Marlon A Guerrero

Interests

Research

Dr. Guerrero’s research interest includes the study of thyroid carcinogenesis, advanced thyroid cancers and adrenocortical carcinoma. He is also interested in the systemic effects of the hypercalcemia seen in primary hyperparathyroidism. Dr. Guerrero has been very active in clinical research and has many publications and several presentations in national meetings.

Courses

Scholarly Contributions

Chapters

• Guerrero, M. A. (2017). Sonographic appearance of abnormal cervical lymph nodes in the pre-operative and re-operative/empty neck. In Advanced Thyroid and Parathyroid Ultrasound(pp 215-225).
• Guerrero, M. A., & Maria, M. (2017). Current Management of Adrenal Incidentalomas. In Clinical Management of Adrenal Tumors(pp 1-15). Rijeka, Croatia: Intech.
• Samuel, S., & Guerrero, M. A. (2015). The evidence for and against parathyroid cryopreservation: should we continue to promote parathyroid cryopreservation?. In Difficult Decisions in Endocrine Surgery: An Evidence-Based Approach..
• Rose, J., & Guerrero, M. A. (2012). Management of Primary Hyperparathyroidism. New insights into some old and some new issues. In Thyroid and Parathyroid Diseases.(pp 203-220). Rijeka, Croatia: Intech.
• Guerrero, M. A., & Kebebew, E. (2011). Secondary and Tertiary Hyperparathyroidism. In Current Surgical Therapy. Philadelphia, PA: Saunders, Elsevier Inc.
• Guerrero, M. A., & Perrier, N. (2008). Thyroid Cancer: Conn’s Current Therapy. In Conn's Current Therapy. Philadelphia, PA: Saunders, Elsevier Inc.
• Zhou, W., Zhou, W., Guerrero, M. A., & Lumsden, A. B. (2006). Lower Extremity Arterial Disease. In Endovascular Therapy: Principles of Peripheral Interventions(pp 186-205). Blackwell Science Ltd, Oxford UK: Wiley. doi:10.1002/9780470994863.CH12

Journals/Publications

• El Ghouayel, M., Hamidi, M., Mazis, C., Imam, Z., Abbad, M., Boutall, A., Guerrero, M., & Nfonsam, V. (2022). Surgical Outcomes in Patients With Preoperative Anemia Undergoing Colectomy for Colon Cancer. The Journal of surgical research, 273, 218-225.
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  Preoperative anemia is relatively common in colon cancer patients; however, its impact on short-term surgical outcomes is not well established. The aim of our study was to evaluate short-term surgical outcomes in colon cancer patients with preoperative anemia undergoing colectomy.
• Guerrero, M. A., Anderson, B., Carr, G., Snyder, K. L., Boyle, P., Ugwu, S. A., Davis, M., Bohnenkamp, S. K., Nfonsam, V., & Riall, T. S. (2021). Adherence to a standardized infection reduction bundle decreases surgical site infections after colon surgery: a retrospective cohort study on 526 patients. Patient safety in surgery, 15(1), 15.
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  Colon surgical site infections (SSI) are detrimental to patient safety and wellbeing. To achieve clinical excellence, our hospital set to improve patient safety for those undergoing colon surgery. Our goal was to implement a perioperative SSI prevention bundle for all colon surgeries to reduce colon surgery SSI rates.
• LePoidevin, L., Erebari, C., Kennedy, T., Heiler, J., Jamplis, R., Sheidan, J., Maillet, M., Viscusi, R., Guerrero, M. A., & Henry, M. (2019). Benefit of Peer–to–Peer Instruction in Surgery Clerkship Orientation.. Journal of The American College of Surgeons.
• Memeh, K. O., Palacios, J. E., Khan, R., & Guerrero, M. A. (2019). PRE-OPERATIVE LOCALIZATION OF PARATHYROID ADENOMA: PERFORMANCE OF 4D MRI PARATHYROID PROTOCOL. Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists, 25(4), 361-365.
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  Accurate pre-operative image localization is critical in the selection of minimally invasive parathyroidectomy as a surgical treatment approach in patients with primary hyperparathyroidism (PHPT). Sestamibi scan, ultrasound, computed tomography, and conventional magnetic resonance imaging (MRI) has varying accuracy in localizing parathyroid adenoma (PTA). Our group has previously shown that four-dimensional (4D) MRI is more accurate than conventional imaging in identifying single adenomas. In this study, we set out to determine if it is possible to accurately localize the quadrant of the adenoma using 4D MRI. We analyzed and matched the quadrants of PTA identified by pre-operative 4D-MRI with the operative findings during parathyroidectomy for PHPT at our institution during the study period. All resections were confirmed to be successful with an adequate decrease in intraoperative parathyroid hormone as defined by the Miami criterion. A total of 26 patients with PHPT underwent pre-operative localization with the 4D MRI parathyroid protocol. Fourteen patients had true single-gland adenoma (SGA) and 12 patients had multi-gland disease (MGD). 4D MRI accurately identified all the SGA. Using this method, we were also able to localize the adenoma in the correct quadrant in 14 of the 18 patients with SGA. All 3 double adenomas were accurately identified using 4D MRI; however, MGD was only accurately identified 67% of the time. The 4D MRI had an overall 85% accuracy in distinguishing SGA from MGD. 4D MRI accurately identified single and double adenomas in their respective quadrants. However, accuracy was lower with MGD. = bilateral neck exploration; = computed tomography; = intra-operative parathyroid hormone; = multi-gland disease; = sestamibi; = minimally invasive parathyroidectomy; = magnetic resonance imaging; = primary hyperparathyroidism; = parathyroid adenoma; = parathyroid hormone; = single-gland adenoma; = single photon emission computed tomography; = four-dimensional.
• Lodewijk, L., Kluijfhout, W. P., Kist, J. W., Stegeman, I., Plukker, J. T., Nieveen van Dijkum, E. J., Bonjer, H. J., Bouvy, N. D., Schepers, A., de Wilt, J. H., Netea-Maier, R. T., van der Hage, J. A., Burger, J. W., Ho, G., Lee, W. S., Shen, W. T., Aronova, A., Zarnegar, R., Benay, C., , Mitmaker, E. J., et al. (2016). Characteristics of contralateral carcinomas in patients with differentiated thyroid cancer larger than 1 cm. Langenbeck's archives of surgery, 401(3), 365-73.
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  Traditionally, total thyroidectomy has been advocated for patients with tumors larger than 1 cm. However, according to the ATA and NCCN guidelines (2015, USA), patients with tumors up to 4 cm are now eligible for lobectomy. A rationale for adhering to total thyroidectomy might be the presence of contralateral carcinomas. The purpose of this study was to describe the characteristics of contralateral carcinomas in patients with differentiated thyroid cancer (DTC) larger than 1 cm.
• Aschebrook-Kilfoy, B., James, B., Nagar, S., Kaplan, S., Seng, V., Ahsan, H., Angelos, P., Kaplan, E. L., Guerrero, M. A., Kuo, J. H., Lee, J. A., Mitmaker, E. J., Moalem, J., Ruan, D. T., Shen, W. T., & Grogan, R. H. (2015). Risk Factors for Decreased Quality of Life in Thyroid Cancer Survivors: Initial Findings from the North American Thyroid Cancer Survivorship Study. Thyroid : official journal of the American Thyroid Association, 25(12), 1313-21.
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  The prevalence of thyroid cancer survivors is rising rapidly due to the combination of an increasing incidence, high survival rates, and a young age at diagnosis. The physical and psychosocial morbidity of thyroid cancer has not been adequately described, and this study therefore sought to improve the understanding of the impact of thyroid cancer on quality of life (QoL) by conducting a large-scale survivorship study.
• Martinez, C., Omesiete, P., Pandit, V., Thompson, E., Nocera, M., Riall, T., Guerrero, M., & Nfonsam, V. (2020). A Protocol-Driven Reduction in Surgical Site Infections After Colon Surgery. The Journal of surgical research, 246, 100-105.
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  Surgical site infection (SSI) is an established quality indicator and predictor for adverse patient outcomes. Multiple strategies have been established to reduce SSI; however, optimum protocol remains unclear. The aim of the study was to assess the impact of established protocol on SSI after colon surgery.
• Nael, K., Bauer, A., Khan, R., & Guerrero, M. A. (2015). Dynamic 4D MRI for Characterization of parathyroid Adenomas: Multiparametric Analysis. American Journal of Neuroradiology, 36(11), 2147-52. doi:10.3174/ajnr.A4425
• Venkat, R., & Guerrero, M. A. (2015). Assessment of Morbidity and Mortality after Adrenalectomy using Modified Frailty Index – A National Surgical Quality Improvement Program Analysis. Journal of The American Colleege of Surgeons.
• Venkat, R., & Guerrero, M. A. (2015). Risk factors and outcomes of blood transfusions in adrenalectomy. The Journal of surgical research, 199(2), 505-11.
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  Blood transfusion has been shown to be associated with adverse long-term and short-term outcomes. We sought to evaluate the preoperative risk factors associated with blood transfusion and its effects on postoperative outcomes after adrenalectomy.
• Venkat, R., & Guerrero, M. A. (2015). Risk factors and postoperative outcomes of blood transfusion after adrenalectomy: A NSQIP analysis.. Journal of Surgical Research.
• Glazer, E. S., Stanko, K., Ong, E. S., & Guerrero, M. A. (2014). Decreased inpatient mortality in obese patients with abdominal nets. Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists, 20(12), 1309-14.
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  Neuroendocrine tumors (NETs) of the abdomen are rare tumors with an incidence of 3.56 per 100,000 in the general population. Obesity is a growing public health problem with varying effects on the severities of other diseases. We investigated the association between obesity and inpatient morbidity/mortality in patients with abdominal NETs utilizing the Nationwide Inpatient Sample (NIS).
• Glazer, E., Stanko, K., Ong, E., & Guerrero, M. (2014). Decreased Inpatient Mortality in Obese Patients with Abdominal Nets. Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists, 1-20.
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  Neuroendocrine tumors (NETs) of the abdomen are rare tumors with an incidence of 3.56 per 100,000 in the general population. Obesity is a growing public health problem with varying effects on severity of other disease. We investigated the association between obesity and inpatient morbidity/mortality in patients with abdominal neuroendocrine tumors utilizing the Nationwide Inpatient Sample (NIS).
• Guerrero, M. A., & Cardenas, A. (2014). Complications After Thyroidectomy and Parathyroidectomy at Teaching Hospitals: A Nationwide Inpatient Sample Analysis. Journal of Surgical Research, 186(2), 675. doi:10.1016/j.jss.2013.11.825
• Venkat, R., Guerrero, M. A., & Cardenas, A. R. (2014). Outcomes after pancreatectomy with surgical resident involvement: an American College of Surgeons National Surgical Quality Improvement Program analysis. Journal of The American College of Surgeons, 219(4), e108. doi:10.1016/j.jamcollsurg.2014.07.673
• Venkat, R., Valdivia, P. L., & Guerrero, M. A. (2014). Resident participation and postoperative outcomes in adrenal surgery. The Journal of surgical research, 190(2), 559-64.
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  The changing paradigm of surgical residency training has raised concerns about the effects on the quality of training. The purpose of this study is to identify if resident participation in laparoscopic adrenalectomy (LA) and open adrenalectomy (OA) cases is associated with deleterious outcomes.
• Campbell, M. J., McCoy, K. L., Shen, W. T., Carty, S. E., Lubitz, C. C., Moalem, J., Nehs, M., Holm, T., Greenblatt, D. Y., Press, D., Feng, X., Siperstein, A. E., Mitmaker, E., Benay, C., Tabah, R., Oltmann, S. C., Chen, H., Sippel, R. S., Brekke, A., , Vriens, M. R., et al. (2013). A multi-institutional international study of risk factors for hematoma after thyroidectomy. Surgery, 154(6), 1283-89; discussion 1289-91.
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  Cervical hematoma can be a potentially fatal complication after thyroidectomy, but its risk factors and timing remain poorly understood.
• Hannallah, J., Rose, J., & Guerrero, M. A. (2013). Comprehensive literature review: recent advances in diagnosing and managing patients with poorly differentiated thyroid carcinoma. International journal of endocrinology, 2013.
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  Poorly differentiated thyroid carcinomas are a rare form of thyroid carcinomas; they display an intermediate behavior between well-differentiated and anaplastic thyroid carcinomas. PDTCs are more aggressive than the well-differentiated, but less aggressive than the undifferentiated or anaplastic, forms. No clinical features can accurately diagnose poorly differentiated thyroid carcinomas. Thus, the results of histocytology, immunohistochemistry, and molecular genetics tests aid in diagnosis. Given the aggressiveness of poorly differentiated thyroid carcinomas and the poor survival rates in patients who undergo surgery alone, a multimodality treatment approach is required. We conducted a comprehensive review of the current diagnostic and therapeutic tools in the management of patients with poorly differentiated thyroid carcinomas.
• Korovin, L. N., & Guerrero, M. A. (2013). Laterality of central venous sampling: lack of effect on the accuracy of intraoperative parathyroid hormone monitoring. American journal of surgery, 206(6), 883-6.
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  The purpose of this study was to determine if laterality of internal jugular vein (IJV) sampling affects the accuracy of intraoperative parathyroid hormone (PTH) monitoring during parathyroidectomy for primary hyperparathyroidism.
• Nielsen, V. G., Garol, B. D., Zelman, E. A., & Guerrero, M. A. (2013). Hemeoxygenase-1 mediated hypercoagulability in a patient with thyroid cancer. Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis, 24(6), 663-5.
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  Thyroid cancers can cause significant regional thrombotic morbidity and mortality. Of interest, thyroid cancer cell lines can have upregulation of the carbon monoxide-producing enzyme, hemeoxygenase-1. Carbon monoxide has been demonstrated to markedly enhance plasmatic coagulation in vitro and in vivo via enhancement of fibrinogen's substrate properties by binding to a fibrinogen-associated heme group(s). We present a patient undergoing removal of a malignant thyroid tumour who was serendipitously found to have abnormally increased carboxyhaemoglobin concentration (2.4%) and plasmatic hypercoagulability with a carbon monoxide-mediated clot strength as determined by a thrombelastographic method. This initial observation serves as a rationale to further investigate the role played by hemeoxygenase-1 upregulation in the setting of cancers associated with increased endogenous carbon monoxide production.
• Rose, J., Wertheim, B. C., & Guerrero, M. A. (2013). Regional Differences in Thyroid Cancer Presentation and Survival: A SEER Study. Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists, 19(6), 998-1006.
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  Objective: The incidence of thyroid cancer has been steadily increasing. Several studies have identified differences in the incidence and prognosis of thyroid cancer according to gender and racial/ethnic differences. In this study, we sought to determine if stage of presentation and survival rate of patients with thyroid cancer in the United States was affected by geographic region.Methods: Using the Surveillance, Epidemiology, and End Results (SEER) database, we identified 100,404 patients with thyroid cancer from 1973 through 2009. We assessed historical stage of diagnosis and cancer-free survival rate according to geographic region. To compare stages of diagnosis, we used multinomial logistic regression. To compare survival rates, we used Cox proportional hazards regression. Models were adjusted for age, year of diagnosis, cancer type, registry site, race/ethnicity, and stage.Results: Of 100,404 patients, 52,902 (52.3%) were from the West, 17,915 (17.8%) from the East, 15,302 (15.2%) from the South, and 14,285 (14.2%) from the Midwest. Overall, most presented with localized disease. Those from the West had a higher risk of presenting with regional and distant metastases. When we double-stratified by cancer subtype and racial group, we found no significant associations between geographic region and cancer-free survival rate.Conclusion: The presentation stage and survival rate of patients with thyroid cancer differed by geographic region, but not within separate racial/ethnic groups.
• Venkat, R., & Guerrero, M. A. (2013). Recent advances in the surgical treatment of differentiated thyroid cancer: a comprehensive review. The Scientific World Journal, 2013.
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  Differentiated thyroid cancers have become one of the fastest growing malignancies in the world. While surgery has remained the cornerstone of management of these tumors, the surgical approach has seen numerous innovations over the past few decades. The use of video-assistance and robotics has revolutionized thyroid surgery. This paper provides a comprehensive evaluation of the different approaches to thyroid surgery, the utility of prophylactic and therapeutic lymph node dissection, and evidence-based guidelines in the treatment of differentiated thyroid cancers. Minimally invasive video-ssisted thyroidectomy is both safe and effective in the hands of the trained surgeon and, in selected patient populations, has comparative perioperative morbidity and better cosmesis as compared to conventional open thyroidectomy. It is universally accepted that therapeutic central lymph node dissection should be performed when metastatic lymph nodes are identified on physical exam, ultrasound, or intraoperatively. In the absence of overt nodal metastasis, the role of elective prophylactic central lymph node dissection remains a matter of debate and prospective, randomized studies are warranted to evaluate the utility of this procedure.
• Rose, J., Wertheim, B. C., & Guerrero, M. A. (2012). Radiation treatment of patients with primary pediatric malignancies: risk of developing thyroid cancer as a secondary malignancy. American Journal of Surgery, 204(6), 881-6.
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  The aim of this study was to estimate the risk of thyroid cancer as a secondary malignancy after radiation treatment of primary pediatric malignancies.
• Safavi, A., Vijayasekaran, A., & Guerrero, M. A. (2012). New insight into the treatment of advanced differentiated thyroid cancer. Journal of Thyroid Research, 2012.
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  The vast majority of patients with differentiated thyroid cancer (DTC) are treated successfully with surgery and radioactive iodine ablation, yet the treatment of advanced cases is frustrating and largely ineffective. Systemic treatment with conventional cytotoxic chemotherapy is basically ineffective in most patients with advanced DTC. However, a better understanding of the genetics and biologic basis of thyroid cancers has generated opportunities for innovative therapeutic modalities, resulting in several clinical trials. We aim to delineate the latest knowledge regarding the biologic characteristics of DTC and to describe the available data related to novel targeted therapies that have demonstrated clinical effectiveness.
• Schreinemakers, J. M., Vriens, M. R., Munoz-Perez, N., Guerrero, M. A., Suh, I., Rinkes, I. H., Gosnell, J., Shen, W. T., Clark, O. H., & Duh, Q. (2012). Fluorodeoxyglucose-positron emission tomography scan-positive recurrent papillary thyroid cancer and the prognosis and implications for surgical management. World journal of surgical oncology, 10, 192.
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  To compare outcomes for patients with recurrent or persistent papillary thyroid cancer (PTC) who had metastatic tumors that were fluorodeoxyglucose-positron emission tomography (FDG-PET) positive or negative, and to determine whether the FDG-PET scan findings changed the outcome of medical and surgical management.
• Tsikitis, V. L., Wertheim, B. C., & Guerrero, M. A. (2012). Trends of incidence and survival of gastrointestinal neuroendocrine tumors in the United States: a seer analysis. Journal of Cancer, 3, 292-302.
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  To examine trends in detection and survival of hollow viscus gastrointestinal neuroendocrine tumors (NETs) across time and geographic regions of the U.S.
• Vijayasekaran, A., Maegawa, F., & Guerrero, M. (2012). A rare finding of an ectopic parathyroid gland within a cervical thymic cyst presenting as a lateral neck mass. The American surgeon, 78(3), E171-2.
• Vriens, M. R., Weng, J., Suh, I., Huynh, N., Guerrero, M. A., Shen, W. T., Duh, Q., Clark, O. H., & Kebebew, E. (2012). MicroRNA expression profiling is a potential diagnostic tool for thyroid cancer. Cancer, 118(13), 3426-32.
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  Approximately 30% of fine-needle aspiration (FNA) biopsies of thyroid nodules are indeterminate or nondiagnostic. Recent studies suggest microRNA (miRNA, miR) is differentially expressed in malignant tumors and may have a role in carcinogenesis, including thyroid cancer. The authors therefore tested the hypothesis that miRNA expression analysis would identify putative markers that could distinguish benign from malignant thyroid neoplasms that are often indeterminate on FNA biopsy.
• Guerrero, M. A., & Clark, O. H. (2011). Controversies in the management of papillary thyroid cancer revisited. ISRN oncology.
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  The debate on the appropriate treatment of patients with papillary thyroid cancer (PTC) has persisted for several decades. The main controversies focus on the extent of surgery, the timing of central neck dissection, and the indications for radioactive iodine ablation. These controversies continue, for the most part, due to the good prognosis of PTC patients and the questionable effect these treatment modalities have on patient survival. This paper addresses these three controversies and the role of molecular tumor markers in the appropriate treatment selection.
• Guerrero, M. A., Lindsay, S., Suh, I., Vriens, M. R., Khanafshar, E., Shen, W. T., Gosnell, J., Kebebew, E., Duh, Q., & Clark, O. H. (2011). Medullary Thyroid Cancer: It is a pain in the neck?. Journal of Cancer, 2, 200-5.
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  Medullary thyroid cancer (MTC) commonly presents with lymph node (LN) metastases, and has a worse prognosis than papillary thyroid cancer (PTC). Tumor size and LN involvement have been shown to affect stage of disease; however, to our knowledge, ours is the first study that attempts to correlate anterior neck pain on presentation with the extent of disease.
• Palstra, A. P., Guerrero, M. A., de Laak, G., Klein Breteler, J. P., & van den Thillart, G. E. (2011). Temporal progression in migratory status and sexual maturation in European silver eels during downstream migration. Fish physiology and biochemistry, 37(2), 285-96.
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  The onset of downstream migration of European eels is accompanied by a cessation of feeding and the start of sexual maturation which stresses the link between metabolism and sexual maturation, also suggesting an important role for exercise. Exercise has been tested with eels in swim tunnels and was found to stimulate the onset of sexual maturation. In this study, we have investigated the interplay between migration and maturation in the field during the downstream migration of female silver eels. Temporal changes in migratory status and sexual maturation among silver eels of the upstream Rhine River system over 3 months of the migration season (August, September and October) were determined in biometrical parameters, plasma 17β-estradiol and calcium levels, oocyte histology and gonadal fat levels. Furthermore, the ecological relevant parameters age as determined by otolithometry and health aspects indicated by haematocrit, haemoglobin and swim-bladder parasite load were measured. Silver eels were estimated to be 14 years old. A strong temporal progression in migratory stage was shown over the months of downstream migration. Catches probably represented a mix of reproductive migrants and feeding migrants of which the ratio increased over time. Furthermore, this study confirmed our hypothesis linking the migratory stage to early maturation as indicated by enlargement of the eyes, oocyte growth and fat deposition in the oocytes, exactly the same changes as found induced by exercise but not ruling out environmental influences. Migrants show extensive fat uptake by the oocytes, probably stimulated by the swimming exercise. In addition, at least 83% of the silver eels in this spawning run may have suffered from negative effects of swim-bladder parasites on their swimming performance.
• Rahbari, R., Mathur, A., Kitano, M., Guerrero, M., Shen, W. T., Duh, Q. Y., Clark, O. H., & Kebebew, E. (2011). Prospective randomized trial of ligasure versus harmonic hemostasis technique in thyroidectomy. Annals of surgical oncology, 18(4), 1023-7.
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  Two surgical devices have become popular in thyroid surgery: a bipolar energy sealing system (B) and ultrasonic coagulation (UC). Retrospective and prospective studies have demonstrated that the use of these surgical devices for thyroidectomy compared with conventional thyroidectomy (clamp-and-tie) techniques reduces operative time and cost. We conducted a prospective randomized clinical trial to determine if there is any difference in operative time and cost between B and UC.
• Guerrero, M. A. (2010). Cryopreservation of parathyroid glands. International Journal of Endocrinology.
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  The risk of permanent hypoparathyroidism following thyroid and parathyroid surgery is around 1% in the hands of experienced endocrine surgeons. Although this complication is rare, rendering a patient permanently aparathyroid has significant consequences on the health and quality of life of the patient. Immediate autotransplantation of parathyroid glands that are injured or unintentionally removed offers the best possibility of graft viability and functionality. However, since the majority of cases of hypoparathyroidism are transient, immediate autotransplantation can complicate postoperative surveillance in certain patients, especially those with primary hyperparathyroidism. Cryopreservation of parathyroid tissue is an alternate technique that was developed to treat patients with permanent hypoparathyroidism. This method allows for parathyroid tissue to be stored and then autotransplanted in a delayed fashion once permanent hypoparathyroidism is confirmed. This article provides a contemporary review on cryopreservation of parathyroid tissue and its current role in thyroid and parathyroid surgery.
• Guerrero, M. A., & Clark, O. (2010). A Comprehensive Review of Intraoperative Parathyroid Hormone Monitoring. World Journal of Endocrine Surgery, 2(1), 21-27.
• Guerrero, M. A., & Kebebew, E. (2010). Adrenocortical carcinoma and synchronous malignancies. Journal of Cancer, 1, 108-11.
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  Adrenocortical carcinoma (ACC) is an aggressive tumor that accounts for 0.02% of all reported cancers. ACC commonly arises in a sporadic manner, but may also manifest as part of a familial syndrome. Regardless of the setting, ACC rarely arises concurrent with other malignant tumors.
• Guerrero, M. A., Suh, I., Vriens, M. R., Shen, W. T., Gosnell, J., Kebebew, E., Clark, O. H., & Duh, Q. (2010). The number of needle passes affects the accuracy of parathyroid hormone assay with intraoperative parathyroid aspiration. American journal of surgery, 200(6), 701-5; discussion 705-6.
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  Intraoperative aspiration of a nodule and parathyroid hormone (PTH) assay has been shown to accurately confirm parathyroid tissue. However, the reported aspiration technique varies in the literature. We sought to determine if the number of passes affected the accuracy of PTH analysis.
• Guerrero, M. A., Suh, I., Vriens, M. R., Shen, W. T., Gosnell, J., Kebebew, E., Duh, Q., & Clark, O. H. (2010). Age and tumor size predicts lymph node involvement in Hürthle Cell Carcinoma. Journal of Cancer, 1, 23-6.
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  Hürthle cell carcinoma (HCC) is a rare tumor that tends to metastasize to the lymph nodes. Some studies have correlated size of Hürthle cell tumors with the risk of malignancy. Whether the size of HCC correlates with the risk of lymph node (LN) metastases, to our knowledge has not been addressed.
• Suh, I., Vriens, M. R., Guerrero, M. A., Griffin, A., Shen, W. T., Duh, Q., Clark, O. H., & Kebebew, E. (2010). Serum thyroglobulin is a poor diagnostic biomarker of malignancy in follicular and Hurthle-cell neoplasms of the thyroid. American Journal of Surgery, 200(1), 41-6.
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  Serum thyroglobulin (Tg) is the most accurate biomarker for thyroid cancer recurrence. However, some clinicians measure preoperative Tg as a diagnostic cancer marker despite lack of supporting evidence. We examined whether Tg accurately predicts malignancy in follicular or Hürthle-cell neoplasms.
• Guerrero, M. A., Schreinemakers, J. M., Vriens, M. R., Suh, I., Hwang, J., Shen, W. T., Gosnell, J., Clark, O. H., & Duh, Q. (2009). Clinical spectrum of pheochromocytoma. Journal of the American College of Surgeons, 209(6), 727-32.
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  Pheochromocytomas vary in presentation, tumor size, and in catecholamine production. Whether pheochromocytoma size correlates with hormone levels, clinical presentation, and perioperative complications is not known. The goal of this study was to determine if tumor size and hormone level correlate according to the clinical presentation at diagnosis.
• Guerrero, M. A., Vriens, M. R., Suh, I., Khanafshar, E., & Clark, O. H. (2009). Intraoperative diagnostic strategy to distinguish parathyroid adenomas from metastatic thyroid cancer. Endocrinology Practice, 15(5), 454-7.
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  To report the limitations of frozen section examination and the value of intraoperative tissue aspiration for parathyroid hormone assay to distinguish parathyroid adenomas from metastatic thyroid carcinoma.
• Moalem, J., Guerrero, M., & Kebebew, E. (2009). Bilateral neck exploration in primary hyperparathyroidism--when is it selected and how is it performed?. World Journal of Surgery, 33(11), 2282-91.
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  Although most patients with primary hyperparathyroidism (PHPT) are ideal candidates for minimally invasive parathyroidectomy, some will have more than one enlarged gland and require bilateral neck exploration to achieve biochemical cure. We evaluated the clinical evidence for when to choose bilateral neck exploration for patients with PHPT.
• Sinigalliano, C. D., Winshell, J., Guerrero, M. A., Scorzetti, G., Fell, J. W., Eaton, R. W., Brand, L., & Rein, K. S. (2009). Viable cell sorting of dinoflagellates by multiparametric flow cytometry. Phycologia, 48(4), 249-257.
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  Electronic cell sorting for isolation and culture of dinoflagellates and other marine eukaryotic phytoplankton was compared to the traditional method of manually picking cells using a micropipette. Trauma to electronically sorted cells was not a limiting factor, as fragile dinoflagellates, such as Karenia brevis (Dinophyceae), survived electronic cell sorting to yield viable cells. The rate of successful isolation of large-scale (> 4 litres) cultures was higher for manual picking than for electronic cell sorting (2% vs 0.5%, respectively). However, manual picking of cells is more labor intensive and time consuming. Most manually isolated cells required repicking, as the cultures were determined not to be unialgal after a single round of isolation; whereas, no cultures obtained in this study from electronic single-cell sorting required resorting. A broad flow cytometric gating logic was employed to enhance species diversity. The percentages of unique genotypes produced by manual picking or electronic cell sorting were similar (57% vs 54%, respectively), and each approach produced a variety of dinoflagellate or raphidophyte genera. Alternatively, a highly restrictive gating logic was successfully used to target K. brevis from a natural bloom sample. Direct electronic single-cell sorting was more successful than utilizing a pre-enrichment sort followed by electronic single-cell sorting. The appropriate recovery medium may enhance the rate of successful isolations. Seventy percent of isolated cells were recovered in a new medium (RE) reported here, which was optimized for axenic dinoflagellate cultures. The greatest limiting factor to the throughput of electronic cell sorting is the need for manual postsort culture maintenance and assessment of the large number of isolated cells. However, when combined with newly developed automated methods for growth screening, electronic single-cell sorting has the potential to accelerate the discovery of new algal strains.
• Suh, I., Filetti, S., Vriens, M. R., Guerrero, M. A., Tumino, S., Wong, M., Shen, W. T., Kebebew, E., Duh, Q., & Clark, O. H. (2009). Distinct loci on chromosome 1q21 and 6q22 predispose to familial nonmedullary thyroid cancer: a SNP array-based linkage analysis of 38 families. Surgery, 146(6), 1073-80.
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  Familial nonmedullary thyroid cancer (FNMTC) is associated with earlier onset and more aggressive behavior than its sporadic counterpart. Although candidate chromosomal loci have been proposed for isolated families with variants of FNMTC, the etiology of most cases is unknown. We aimed to identify loci linked to FNMTC susceptibility using single-nucleotide polymorphism (SNP) array-based linkage analysis in a broad sampling of affected families.
• Suh, I., Guerrero, M. A., & Kebebew, E. (2009). Gene-expression profiling of adrenocortical carcinoma. Expert Review of Molecular Diagnostics, 9(4), 343-51.
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  Adrenocortical carcinoma (ACC) is a rare malignancy of the adrenal cortex, associated with a generally dismal prognosis owing to its aggressive behavior. The clinical management of ACC is complicated by the inadequacy of current diagnostic modalities to accurately distinguish benign from malignant adrenocortical tumors. In addition, efforts to better predict clinical tumor behavior are limited by the lack of a better understanding of the molecular mechanisms of adrenocortical carcinogenesis. There have been no significant improvements in the treatment of ACC. Thus, there is a pressing need for the development of new therapeutic approaches for patients with ACC, as most patients present with advanced locoregional and metastatic disease. The prospects of identifying diagnostic and prognostic markers or gene profiles for ACC have significantly improved with the development of genome-wide gene-expression analysis. Since 2003, several studies have reported distinct gene-expression profiles between benign and malignant adrenocortical tumors that may have diagnostic and prognostic clinical utility. In this article, we discuss the limitations of the clinical management of ACC, and the gene-expression profile studies that have attempted to address these limitations.
• Vriens, M. R., Schreinemakers, J. M., Suh, I., Guerrero, M. A., & Clark, O. H. (2009). Diagnostic markers and prognostic factors in thyroid cancer. Future Oncology (London, England), 5(8), 1283-93.
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  There has been considerable progress identifying biomarkers in thyroid tumors that improve the accuracy of fine-needle aspiration biopsy and also help predict tumor aggressiveness or behavior. In this review we address both the clinical potential of molecular biomarkers and their usefulness, based on the most recent literature. We describe the current best clinical staging systems and the common somatic mutations in thyroid cancer. The BRAF mutation is the most common mutation in papillary thyroid cancer and has recently been reported to be associated with disease aggressiveness; it is also an independent predictor of tumor behavior. Combined testing of RET/PTC, NTRK, RAS and PAX8-PPARgamma, which are mutually exclusive mutations, helps improve the accuracy of fine-needle aspiration biopsy. Gene-expression profiling studies have identified a variety of potential molecular markers to help distinguish benign from malignant thyroid neoplasms. Expression analysis of differentially expressed microRNAs also appears to be a promising diagnostic approach for distinguishing benign from malignant thyroid neoplasm. It is especially useful for indeterminate nodules by fine-needle aspiration biopsy.
• Guerrero, M. A., Evans, D. B., Lee, J. E., Bao, R., Bereket, A., Gantela, S., Griffin, G. D., & Perrier, N. D. (2008). Viability of cryopreserved parathyroid tissue: when is continued storage versus disposal indicated?. World Journal of Surgery, 32(5), 836-9.
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  Parathyroid cryopreservation is used for potential autografting in patients who are rendered hypocalcemic following surgery. Cryopreservation employs multiple resources and carries a significant cost for processing and storage of tissue. Importantly, the length of time that parathyroid tissue remains functional after cryopreservation is not known. The goal of our study was to assess ex-vivo viability of parathyroid tissue in relation to the length of time in storage. We sought to define the appropriate time frame for tissue utilization and disposal to assist with long-term surgical planning.
• Philip, M., Guerrero, M. A., Evans, D. B., Hunter, G. J., Edeiken-Monroe, B. S., Vu, T., & Perrier, N. D. (2008). Efficacy of 4D-CT preoperative localization in 2 patients with MEN 2A. Journal of Surgical Education, 65(3), 182-5.
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  Multiple endocrine neoplasia type 2A (MEN2A) is an autosomal dominant syndrome that is associated with hyperparathyroidism in 20% to 30% of adult gene carriers. The appropriate surgical management of these patients remains in question. Approaches to this disease range from selective gland resection to a subtotal parathyroidectomy with or without autotransplantation. Despite surgical intervention, disease recurrence is problematic. Surgical management of patients found to have recurrence relies on localizing the anatomic location of the hyperfunctional gland(s). The primary imaging modality for localization of hyperfunctioning parathyroid glands is technetium 99m sestamibi single photon emission computed tomography (SPECT). Although sestamibi imaging has a sensitivity of 60% to 90%, specific anatomic detail is not always present by this imaging modality. Four-dimensional computed tomography (4D-CT) scans allow localization of ectopic parathyroid glands and autotransplanted parathyroid tissue, and they provide the anatomic detail necessary for decisions about appropriate surgical management. Another benefit of the 4D-CT scan is that enhancement characteristics, which are determined by contrast opacification of the hyperfunctional parathyroid tissue over 4 phases of the scan, correlate with metabolic activity. We recommend the use of 4D-CT scanning because of its capacity to identify hyperfunctional parathyroid glands and to provide anatomic information important in preoperative planning.
• Guerrero, M. A., Cross, C. A., Lin, P. H., Keane, T. E., & Lumsden, A. B. (2007). Inferior vena cava reconstruction using fresh inferior vena cava allograft following caval resection for leiomyosarcoma: midterm results. Journal of Vascular Surgery, 46(1), 140-3.
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  We present a 56-year-old woman affected by a large leiomyosarcoma originating from the suprarenal inferior vena cava (IVC). A computed tomography (CT) scan revealed near obstruction of the IVC and involvement of the right renal vein. The patient underwent successful en bloc resection of the tumor, right kidney, right adrenal gland, and IVC. Caval reconstruction was performed using a non-type specific allograft, followed by left renal vein re-implantation. The patient tolerated the procedure well without any complications. The use of an IVC allograft allowed for continued graft patency, without the need of immunosuppression or long-term anticoagulation. However, local recurrence did occur.
• Guerrero, M. A., Gomberawalla, M., Brandt, M., & Brunicardi, F. (2007). Recurrent Cervical Lymphangioma (Cystic Hygroma) of the Neck in Adults: Case Report and Review of the Literature. Surgical Rounds, 30(11), 542-5.
• Guerrero, M. A., Wray, C. J., Kee, S. S., Frenzel, J. C., & Perrier, N. D. (2007). Minimally invasive parathyroidectomy complicated by pneumothoraces: a report of 4 cases. Journal of surgical education, 64(2), 101-7; discussion 113.
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  The traditional approach to primary hyperparathyroidism has been a bilateral neck exploration for evaluation of all four parathyroid glands. With the advent of minimally invasive surgery, minimally invasive parathyroidectomy has become a popular approach for the treatment of parathyroid adenomas. Though exceedingly rare, pneumothorax formation is a potential complication following this procedure. In this paper, we report four cases of pneumothorax following minimally invasive parathyroidectomies. The commonality in all these cases was positioning with extreme neck hyperextension. Additional risks in three patients were dissection in the superior mediastinum, traction on the thyrothymic ligament, and a low-lying inferior parathyroid gland. One patient developed a pneumothorax prior to dissection along the superior mediastinum. This suggests that further risk factors may be heat conduction from the electrocautery and total intravenous anesthesia with spontaneously breathing of the patient.
• Guerrero, M. A., Zhou, W., El Sayed, H. F., Kougias, P., & Lin, P. H. (2009). Subcapsular hematoma of the kidney secondary to paintball pellet injuries. The Journal of emergency medicine, 36(3), 300-1.
• Guerrero, M. A., Zhou, W., Kougias, P., El Sayed, H., & Lin, P. H. (2007). Multiple giant anastomotic pseudoaneurysms of the carotid and femoral arteries: combined endovascular and open surgical approach. Vascular, 15(3), 158-61.
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  Anastomotic pseudoaneurysm is a known complication following carotid artery endarterectomy and aortobifemoral bypass surgeries. However, giant concurrent carotid and femoral artery anastomotic pseudoaneurysms are rare. We herein report a case of successful treatment of multiple giant anastomotic pseudoaneurysms using a combined endovascular and surgical approach. Our case highlights the fact that endovascular techniques can facilitate open surgical repair of complex anastomotic pseudoaneurysms.
• Lin, P. H., Zhou, W., Guerrero, M. A., McCoy, S. A., Felkai, D., Kougias, P., & El Sayed, H. F. (2006). Carotid artery stenting with distal protection using the carotid wallstent and filterwire neuroprotection: single-center experience of 380 cases with midterm outcomes. Vascular, 14(5), 237-44.
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  Emerging data have supported the clinical efficacy of carotid artery stenting (CAS) in stroke prevention in high-risk surgical patients. This study was performed to evaluate the midterm clinical outcome of CAS using the Carotid Wallstent and FilterWire distal protection (both Boston Scientific, Natick, MA) at an academic institution. Risk factors for in-stent restenosis (ISR) were also analyzed. Clinical variables and treatment outcome of high-risk patients who underwent Carotid Wallstent placement with FilterWire EX/EZ neuroprotection were analyzed during a recent 54-month period. Three hundred eighty CAS procedures were performed in 354 patients. Technical success was achieved in 372 cases (98%), and symptomatic lesions existed in 85 (24%) patients. No patient experienced periprocedural mortality or neuroprotective device-related complication. The 30-day stroke and death rate was 2.7%, and the overall complication rate was 6.9%. The overall major or fatal stroke rates in symptomatic and asymptomatic patients were 4.6% and 1.3%, respectively (not significant). The overall stroke and death rates between the symptomatic and asymptomatic groups were 5.8% and 2.4%, respectively (not significant). The median follow-up period was 29 months (range 1-53 months). With Kaplan-Meier analysis, the rates of freedom from 60% or greater ISR after CAS procedures at 12, 24, 36, and 48 months were 97%, 94%, 92%, and 90%, respectively. The rates of freedom from all fatal and nonfatal strokes at 12, 24, 36, and 48 months were 97%, 91%, 89%, and 85%, respectively. Multivariable analysis of significant univariate predictors identified that postendarterectomy stenosis (odds ratio [OR] 3.98, p = .02) and multiple stent placement (OR 3.68, p = .03) were independent predictors of ISR. Our study yielded favorable short-term and midterm clinical results using Carotid Wallstent with FilterWire neuroprotection. Late follow-up results showed low rates of fatal and nonfatal stroke and favorable ISR rates compared with other carotid stent trials. Postendarterectomy and multiple stent placement were associated with subsequent ISR.
• Zhou, W., Lin, P. H., Bush, R. L., Peden, E. K., Guerrero, M. A., Kougias, P., & Lumsden, A. B. (2006). Management of in-sent restenosis after carotid artery stenting in high-risk patients. Journal of Vascular Surgery, 43(2), 305-12.
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  Carotid artery stenting (CAS) has emerged as an acceptable treatment alternative in patients with carotid bifurcation disease. Although early results of CAS have been promising, long-term clinical outcomes remain less certain. We report herein the frequency, management, and clinical outcome of in-stent restenosis (ISR) after CAS at a single academic institution.
• Zhou, W., Lin, P. H., Bush, R. L., Peden, E., Guerrero, M. A., Terramani, T., Lubbe, D. F., Nguyen, L., & Lumsden, A. B. (2006). Carotid artery aneurysm: evolution of management over two decades. Journal of Vascular Surgery, 43(3), 493-6; discussion 497.
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  Extracranial carotid artery aneurysm (CCA), although uncommon, represents a challenge to treatment strategy. The purpose of this study was to analyze the treatment evolution and clinical outcome of all patients with CCA over a two decade period.
• Zhou, W., Lin, P. H., Bush, R. L., Terramani, T. T., Matsuura, J. H., Cox, M., Peden, E., Guerrero, M., Silberfein, E. J., Dardik, A., Rosenthal, D., & Lumsden, A. B. (2006). In situ reconstruction with cryopreserved arterial allografts for management of mycotic aneurysms or aortic prosthetic graft infections: a multi-institutional experience. Texas Heart Institute Journal, 33(1), 14-8.
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  We designed this study to evaluate a multi-institutional experience regarding the efficacy of cryopreserved aortic allografts in the treatment of infected aortic prosthetic grafts or mycotic aneurysms. We reviewed clinical data of all patients from 4 institutions who underwent in situ aortic reconstruction with cryopreserved allografts for either infected aortic prosthetic graft or mycotic aneurysms from during a 6-year period. Relevant clinical variables and treatment outcomes were analyzed. A total of 42 patients (37 men; overall mean age 63 +/- 13 years, range 41-74 years) were identified during this study period. Treatment indications included 34 primary aortic graft infections (81%), 6 mycotic aneurysms (22%), and 2 aortoenteric erosions (5%). Transabdominal and thoracoabdominal approaches were used in 38 (90%) and 4 patients (10%), respectively. Staphylococcus aureus was the most commonly identified organism (n=27, 64%). Although there was no intraoperative death, the 30-day operative mortality was 17% (n=7). There were 21 (50%) nonfatal complications, including local wound infection (n=8), lower-extremity deep venous thrombosis (n=5), amputation (n=6), and renal failure requiring hemodialysis (n=2). The average length of hospital stay was 16.4 +/- 7 days. During a mean follow-up period of 12.5 months, reoperation for allograft revision was necessary in 1 patient due to graft thrombosis (6%). The overall treatment mortality rate was 21% (n=9). In situ aortic reconstruction with cryopreserved allografts is an acceptable treatment method in patients with infected aortic prosthetic graft or mycotic aneurysms. Our study showed that mid-term graft-related complications such as reinfection or aneurysmal degeneration were uncommon.
• Bush, R. L., Kougias, P., Guerrero, M. A., Lubbe, D. F., Zhou, W., Lumsden, A. B., & Lin, P. H. (2005). A comparison of carotid artery stenting with neuroprotection versus carotid endarterectomy under local anesthesia. American journal of surgery, 190(5), 696-700.
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  Carotid endarterectomy (CEA) and carotid artery stenting (CAS) reduce the risk of stroke in patients with high-grade carotid artery stenosis. Despite the known impact of type of anesthesia on outcome after CEA, none of the current studies comparing CEA with CAS addresses the effect of anesthetic choice on perioperative events. In this study, we compare our results of distally protected CAS versus CEA under local anesthesia.
• Guerrero, M. A., Lin, P. H., Bush, R. L., & Lumsden, A. B. (2005). Splenic and pancreatic infarction due to motorcycle handlebar injury. The Journal of trauma, 58(6), 1304.
• Lin, P. H., Bush, R. L., Nguyen, L., Guerrero, M. A., Chen, C., & Lumsden, A. B. (2005). Anastomotic strategies to improve hemodialysis access patency--a review. Vascular and endovascular surgery, 39(2), 135-42.
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  The number of patients with end-stage renal disease (ESRD) who require maintenance hemodialysis has risen sharply in the past 2 decades. It is estimated that more than 60% of all patients with ESRD who require chronic hemodialysis are accessed through an arteriovenous fistula (AVF) or graft (AVG), and the incidence is increasing at a rate of 2% to 4% per year. The long-term patency rate of an upper extremity AVF or AVG for hemodialysis access remains suboptimal owing in part to progressive stenosis at the venous anastomosis. This article reviews the causative factors of dialysis access-related anastomotic stenosis, or intimal hyperplasia. This article also reviews the clinical experience of various anastomotic strategies to ameliorate the hemodynamic environment in an effort to improve the clinical outcome of hemodialysis access. These strategies include the use of (1) vein cuff at the expanded polytetrafluoroethylene (ePTFE)-venous anastomosis of AVG, (2) cuffed ePTFE dialysis AVG, and (3) anastomotic devices that create an interrupted anastomosis with staples or clips.
• Lin, P. H., Bush, R. L., Peden, E. K., Zhou, W., Guerrero, M., Henao, E. A., Kougias, P., Mohiuddin, I., & Lumsden, A. B. (2005). Carotid artery stenting with neuroprotection: assessing the learning curve and treatment outcome. American journal of surgery, 190(6), 850-7.
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  Carotid artery stenting (CAS) has emerged as an acceptable treatment alternative in high-risk patients with carotid stenosis. The purpose of this study was to assess the effect of the learning curve on treatment complications and the clinical outcomes of CAS.
• Guerrero, M. A., Cox, M., Lumsden, A. B., Reardon, M., & Howell, J. (2004). Embolus of surgical adhesive to the extremities causing acute ischemia: report of two cases. Journal of vascular surgery, 40(3), 571-3.
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  We present 2 cases in which a surgical adhesive embolized to the extremities. In the first case an adhesive was successfully used in the repair of a DeBakey type I aortic dissection. The patient was seen 2 months postoperatively with acute lower extremity ischemia, and a large piece of adhesive was extracted from the iliac and femoral arteries at embolectomy. In the second case the adhesive was used to seal a pericardial patch during repair of a ventricular septal defect. This patient was seen 1 day postoperatively with acute arm ischemia, and the adhesive particle was extracted from the brachial artery during embolectomy.
• Watts, K., Lin, P. H., Bush, R. L., Awad, S., McCoy, S. A., Felkai, D., Zhou, W., Nguyen, L., Guerrero, M. A., Shenaq, S. A., & Lumsden, A. B. (2004). The impact of anesthetic modality on the outcome of carotid endarterectomy. American journal of surgery, 188(6), 741-7.
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  Carotid endarterectomy (CEA) reduces the risk of stroke in patients with high-grade carotid artery stenosis. This study evaluates the clinical outcome of CEA performed under local anesthesia (LA) versus general anesthesia (GA).
• Guerrero, M. A., Ballard, B. R., & Grau, A. M. (2003). Malignant phyllodes tumor of the breast: review of the literature and case report of stromal overgrowth. Surgical oncology, 12(1), 27-37.
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  Cystosarcoma phyllodes constitutes only 0.3-0.9% of all breast tumors. The term "sarcoma" was initially used because of its fleshy appearance, a more modern term is Phyllodes tumor (PT). The behavior of PT constitutes a spectrum from benign and locally recurrent to malignant and metastatic. In a general surgical series, 6.2% of the tumors were malignant. The microscopic appearance of PT is that of epithelial elements and connective tissue stroma. Malignancy is determined by characteristics of the stroma. The metastatic spread of malignant PT is mainly hematogenous to lung, with infrequent lymphatic involvement. Wide local excision with 2 cm margins is the treatment of choice. In 20% of both benign and malignant cases, PT will locally recur. There is no proven benefit of radiation or chemotherapy, although radiotherapy may be useful in selected cases. We present a case of a sarcomatous overgrowth in a malignant phyllodes tumor involving multiple histologic types.

Presentations

• Memeh, K., & Guerrero, M. A. (2019, September). Mixed Iodine–avid and FDG–avid Papillary Thyroid Cancer. American Thyroid Association. Denver, CO.
• Guerrero, M. A. (2016, October 17-19). Thyroid and Parathyroid Ultrasound in Practice: Improving Interpretation, Expanding. American College of Surgeons Congress. Washington, DC: American College of Surgeons.
• Guerrero, M. A. (2014, April 13-16). Panelist: Management of primary hyperparathyroidism. Southwest Surgical Congress, 66th Annual Meeting. Scottsdale, AZ: Southwest Surgical Congress.
• Guerrero, M. A. (2014, April 13-16). Panelist: Management of thyroid cancer. Southwest Surgical Congress, 66th Annual Meeting. Scottsdale, AZ: Southwest Surgical Congress.
• Guerrero, M. A. (2014, April 13-16). Prophylactic central neck dissection in well-differentiated thyroid cancer: Con’s against its use. Southwest Surgical Congress, 66th Annual Meeting. Scottsdale, AZ: Southwest Surgical Congress.
• Guerrero, M. A. (2014, March 1). Panelist; Management of complex thyroid cancers. ENT in the Desert, Updates in Otolaryngology Symposium. Tucson, AZ.
• Guerrero, M. A., & Cardenas, A. (2014, April). Obesity contributes to increased complication rates after thyroidectomy and parathyroidectomy.. Southwest Surgical Congress, 66th Annual Meeting. Scottsdale, AZ.
• Guerrero, M. A. (2013, March 21). Panelist; Management of complex thyroid cancers. ENT in the Desert, Updates in Otolaryngology Symposium. Tucson, AZ.
• Guerrero, M. A. (2012, March). Surgical Oncology Paper Session, Moderator. Southwest Surgical Congress, 64th Annual Meeting. Rancho Palo Verdes, CA: Southwest Surgical Congress.
• Guerrero, M. A. (2012, November). Minimally invasive parathyroidectomy; Should we abandon this approach?. American College of Surgeons, Arizona Chapter. Tucson, AZ: American College of Surgeons.
• Guerrero, M. A. (2011, August 8-12). Approach to patients with advanced and recurrent thyroid cancer. Universidad de Ciencias Médicas International Congress. Costa Rica.
• Guerrero, M. A. (2011, August 8-12). Current management of thyroid nodules and thyroid cancer. Universidad de Ciencias Médicas International Congress. Costa Rica.
• Vijayasekaran, A., Maegawa, F., Gruessner, A., & Guerrero, M. A. (2011, April 7). Parathyroid gland size limits the accuracy of bilateral internal jugular vein sampling of parathyroid hormone in the localization of parathyroid adenomas. The Southwestern Surgical Congress 63rd Annual Meeting. Oahu, HI: The Southwestern Surgical Congress.
• Guerrero, M. A. (2010, October 23-30). Current treatment of thyroid cancer. International Congress Mexicana. Guadalajara, Mexico.
• Guerrero, M. A. (2010, October 23-30). Neuroendocrine tumors of the pancreas. Internal Congress Mexicana. Guadalajara, Mexico.
• Guerrero, M. A. (2010, October 23-30). Primary hyperparathyroidism: Current management. International Congress Mexicana. Guadalajara, Mexico.
• Guerrero, M. A. (2010, October 23-30). Transaxillary thyroidectomy and parathyroidectomy: Technique. International Congress Mexicana. Guadalajara, Mexico.
• Guerrero, M. A. (2010, October). Current treatment guidelines: Adrenal tumors. International Congress Mexicana. Guadalajara, Mexico.
• Guerrero, M. A., Schreinemakers, J., Suh, J., Vriens, M., & Shen, W. (2010, February 3-5). Tumor size predicts lymph node involvement in Hürthle cell carcinoma. Fifth Annual Academic Surgical Congress. San Antonio, TX.
• Guerrero, M. A., Shen, W., & Gosnell, J. (2010, March 21-24). The number of needle passes affects the accuracy of parathyroid hormone assay with intraoperative parathyroid aspiration. Southwestern Surgical Congress 62nd Annual Meeting. Tucson, AZ: Southwestern Surgical Congress.
• Guerrero, M. A. (2009, October 14). Pain is a Predictor of Extensive Disease in Medullary Thyroid Cancer. American College of Surgeons, Scientific Papers Session. Chicago, IL: American College of Surgeons.
• Guerrero, M. A. (2009, October 15). Pain is a Predictor of Extensive Disease in Medullary Thyroid Cancer. American College of Surgeons 95th Clinical Congress. Chicago, IL: American College of Surgeons.
• Guerrero, M. A. (2009, September 25). Tumor size predicts lymph node involvement in Hürthle cell carcinoma.. American Thyroid Association Meeting. Palm Beach, FL: American Thyroid Association.
• Guerrero, M. A. (2009, September 26). Medullary Thyroid Cancer: A Pain in the Neck!. American Thyroid Association Meeting. Palm Beach, FL: American Thyroid Association.

Poster Presentations

• Guerrero, M. A. (2018, January). Standardized Infection Reduction Bundle Leads to Decrease in Colorectal Surgical Site Infection. Academic Surgical Congress. Jacksonville, FL.
• Guerrero, M. A., & Mehem, K. O. (2017, April). The Sensitivity of 4D MRI in Preoperative Localization of Parathyroid Adenoma is Influenced by the Size of the Adenoma. Southwestern Surgical Congress.

Others

• Guerrero, M. A. (2017, December). Endocrine Quiz. The SCORE Portal.
• Guerrero, M. A. (2017, October). Thyroid Quiz. The SCORE Portal.
• Memeh, K., Palacios, J., & Guerrero, M. A. (2016, Spring). Quadrant Localization of Parathyroid Adenoma; Performance of 4D-MRI Neck Parathyroid Protocol. Academic Surgical Congress 2016.
• Venkat, R., & Guerrero, M. A. (2015, April). Risk factors and postoperative outcomes of blood transfusion after adrenalectomy: A NSQIP analysis..
• Cardenas, A., & Guerrero, M. A. (2014, April 13-16). Obesity contributes to increased complication rates after thyroidectomy and parathyroidectomy.. Southwest Surgical Congress, 66th Annual Meeting.
• Cardenas, A., & Guerrero, M. A. (2014, February 4-6). Complications after thyroidectomy and parathyroidectomy at teaching hospitals: A nationwide inpatient sample analysis. Academic Surgical Congress, 9th Annual Conference.
• Cardenas, A., Venkat, R., & Guerrero, M. A. (2014, October 26-30). Outcomes After Pancreatectomy with Surgical Resident Involvement: A NSQIP Analysis.. American College of Surgeons 2014 Clinical Congress.
• Glazer, E., & Guerrero, M. A. (2014, February 4-6). Rates are decreased in obese patients with abdominal neuroendocrine tumors. Academic Surgical Congress, 9th Annual Conference.
• Venkat, R., & Guerrero, M. A. (2014, February 4-6). The impact of resident participation on surgical outcomes in laparoscopic adrenalectomy.. Academic Surgical Congress, 9th Annual Conference.
• Cardenas, A., Ong, E., & Guerrero, M. A. (2013, October 16-20). Patients with multiple comorbidities have more complications after elective thyroid surgery. American Thyroid Association, 83rd Annual Meeting.
• Rose, J., & Guerrero, M. A. (2012, March). Radiation treatment of pediatric malignancies and risk of developing thyroid cancer as a secondary malignancy in adulthood. Southwest Surgical Congress 64th Annual Meeting.
• Rose, J., Wertheim, B., & Guerrero, M. A. (2012, May). Regional differences in stage of presentation and survival of individuals with thyroid cancer. American Association of Clinical Endocrinologists, 21st Annual Scientific and Clinical Congress.
• Vijayasekaran, A., Wertheim, B., & Guerrero, M. A. (2012, March). Limitations of intraoperative bilateral internal jugular venous sampling for parathyroid hormone in patients with primary hyperparathyroidism.. American Association of Endocrine Surgeons Annual Meeting.
• Grogan, R., Kuo, J., Mitmaker, E., & Guerrero, M. A. (2011, March). Large Neck Circumference Decreases the Accuracy of Preoperative Imaging for Primary Hyperparathyroidism. American College of Surgeons.
• Maegawa, F., Vijayasekaran, A., & Guerrero, M. A. (2012, Spring). A rare finding of an ectopic parathyroid gland within a cervical thymic cyst presenting as a lateral neck mass. Southwestern Surgical Congress 63nd Annual Mtg.
• Shufeldt, M., Rilo, H., & Guerrero, M. A. (2011, April). Optimization of parathyroid preparation and cryopreservation.. University of Arizona School of Medicine.
• Vijayasekaran, A., Maegawa, F., Gruessner, A., & Guerrero, M. A. (2011, April). Parathyroid gland size limits the accuracy of bilateral internal jugular vein sampling of parathyroid hormone in the localization of parathyroid adenoma.. Southwestern Surgical Congress 63nd Annual Mtg.
• Guerrero, M. A., Schreinemakers, J., Suh, J., Vriens, M., Shen, W., Gosnell, J., Kebebew, E., Duh, Q., & Clark, O. (2010, February 3-5). Tumor size predicts lymph node involvement in Hürthle cell carcinoma. Fifth Annual Academic Surgical Congress.
• Guerrero, M. A., Shen, W., & Gosnell, J. (2010, March 21-24). The number of needle passes affects the accuracy of parathyroid hormone assay with intraoperative parathyroid aspiration. Southwestern Surgical Congress 62nd Annual Mtg..
• Guerrero, M. A. (2009, September). Tucson Osteopathic Medical Foundation. HealthWise.
• Guerrero, M. A., Lindsay, S., Suh, I., Vriens, M., Khanafshar, E., Schreinemakers, J., Shen, W., Gosnell, J., Kebebew, E., Duh, Q., & Clark, O. (2009, October 14). Pain is a Predictor of Extensive Disease in Medullary Thyroid Cancer.. American College of Surgeons.
• Guerrero, M. A., Lindsay, S., Suh, I., Vriens, M., Khanafshar, E., Schreinemakers, J., Shen, W., Gosnell, J., Kebebew, E., Duh, Q., & Clark, O. (2009, October 15). Pain is a Predictor of Extensive Disease in Medullary Thyroid Cancer.. American College of Surgeons 95th Clinical Congress.
• Guerrero, M. A., Lindsay, s., Suh, I., Vriens, M., Khanafshar, E., Schreinemakers, J., Shen, W., Gosnell, J., Kebebew, E., Duh, Q., & Clark, O. (2009, September 26). Medullary Thyroid Cancer: A Pain in the Neck!. American Thyroid Association Meeting.
• Guerrero, M. A., Suh, I., Vriens, M., Shen, W., Gosnell, J., Kebebew, E., Duh, Q., & Clark, O. (2009, September 25). Tumor size predicts lymph node involvement in Hürthle Cell Carcinoma. American Thyroid Association Meeting.
• Guerrero, M. A., Anaya, D., Bao, R., Gantela, S., Evans, D., Lee, J., Griffin, G., Bereket, A., & Perrier, N. (2007, April). A retrospective analysis to determine ex-vivo viability of cryopreserved parathyroid tissue: Storage or Disposal?. 42nd World Congress of Surgery of the International Society of Surgery International Surgical Week.
• Guerrero, M. A., Perrier, N., Gantela, S., Rich, T., Lee, J., & Evans, D. (2007, April). Optimal surgical approach to MEN 2A-associated hyperparathyroidism.. The Endocrine Society's 89th Annual Meeting.
• Guerrero, M. A., Cox, M., Reardon, M., & Howell, J. (2006, April). Determinants of Functional Outcome following Penetrating Trauma to the Brachial Artery.. American College of Surgeons South Texas Chapter Annual Meeting.
• Guerrero, M. A., Cox, M., Lumsden, A., Reardon, M., & Howell, J. (2004, April). Embolus of Surgical Adhesive to the Extremities Causing Acute Ischemia: A Report of Two Cases. Southwest Surgical Congress 56th Annual Meeting.
• Guerrero, M. A., & Grau, A. (2002, November). Cystosarcoma Phyllodes: A Case Report of Sarcomatous Overgrowth in a Malignant Cystosarcoma Phyllodes Tumor. Southern Medical Association 96th Annual Scientific Assembly.
• Guerrero, M. A., Printz, R., & Granner, D. (2000, August). Identification of the Insulin Signaling Pathway Regulating HKII Gene Activity. Vanderbilt University Diabetes Center Student Research Symposium.
• Cardenas, A., Guerrero, M. A., & McPartland, A. (1996, June). Effects of the SfiD-25 mutation on the function of the SulA inhibitor protein.. Annual NIH-MBRS National Research Symposium.