Marlon A Guerrero
- Associate Professor, Surgery
- Assistant Professor, Otolaryngology
- Vice Chair, Clinical Quality / Performance - Department of Surgery
Dr. Guerrero received his BS in Biology from California State University, East Bay after graduating Cum laude. He earned his medical degree from Meharry Medical College in Nashville, TN where he was elected into the prestigious Alpha Omega Alpha Honor Medical Society. He completed his general surgery residency from the Michael E. DeBakey Department of Surgery at the Baylor College of Medicine in Houston, TX where he was awarded the St. Luke’s Hospital Resident of the Year award in 2005.
Dr. Guerrero became interested in treating endocrine tumors and disorders after his training at the MD Anderson Cancer Center. He entered a prestigious Endocrine Surgery Fellowship at the University of California, San Francisco under the mentorship of the legendary Dr. Orlo H. Clark. He joined the department of surgery at the University of Arizona in July 2009 as Director of Endocrine Surgery. He holds many adjunct positions within the College of Medicine.
- M.D. Medicine, Alpha Omega Alpha
- Meharry Medical College, Nashville, Tennessee, United States
- B.S. Biology, Cum laude
- California State University, Hayward, California, United States
- Vice Chair of Quality and Performance, University of Arizona, Tucson, Arizona (2017 - Ongoing)
- Associate Professor, Department of Surgery, University of Arizona (2015 - Ongoing)
- Associate Program Director, General Surgery Residency Program, University of Arizona, Tucson, Arizona (2014 - 2016)
- Assistant Program Director, General Surgery Program, University of Arizona, Tucson, Arizona (2012 - 2014)
- Medical Student Mentor, Societies Doctor Patient Program, University of Arizona, Tucson, Arizona (2011 - Ongoing)
- Director, Endocrine Surgery Center, University of Arizona, Tucson, Arizona (2009 - Ongoing)
- Assistant Professor, Department of Surgery, University of Arizona, Tucson, Arizona (2009 - 2015)
- Director, Resident Laparoscopy Training, ASTEC lab, University of Arizona Medical Center (2009 - 2010)
- Clinical Instructor, University of California, San Francisco (2008 - 2009)
- Golden Key National Honor Society
- Fall 1997
- Arnold Air Academic Society
- Fall 1996
- Retired Officers Society Outstanding Leadership Award
- Fall 1996
- Air Force ROTC Academic Excellence Award
- Spring 1996
- NIH Funded Biomedical Research Support Scholar
- Spring 1994
- 2017 Castle Connolly Top Doctor
- Summer 2017
- Award for Dean's List for Excellence in Teaching
- College of Medicine, Fall 2015
- Medical Student Teaching Award
- Surgery Clerkship, Spring 2014
- 3rd Place presentation award (poster award)
- American Association of Clinical Endocrinologist, Spring 2012
- Leader in Patient Satisfaction
- 5 East, Banner University Medical Center, Summer 2011
- Outstanding Resident Teaching Award
- Spring 2009
- Presentation Award (oral presentation)
- International Association of Endocrine Surgery, Summer 2007
- Society of Vascular Surgery Travel Scholarship
- Fall 2006
- St. Luke's Elvin L. Shelton Resident of the Year
- St. Luke's Elvin L. Shelton, Spring 2005
- Alpha Omega Alpha Honor Medical Society
- Fall 2003
- Henry Nehemiah Cooper, M.D. Memorial Scholarship
- Fall 2002
- Hears Endowed Scholarship
- Fall 2000
- Jonathon Wayne House Memorial Scholarship
- Fall 2000
Licensure & Certification
- Arizona State Medical License (2009)
- California State Medical License (2008)
- Basic Life Support, American Heart Association (2015)
- American Board of Surgery, Fellow, American College of Surgeons (2008)
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.
General SurgerySURG 810A (Fall 2013)
- 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., Guerrero, M. A., & Lumsden, A. (2006). Lower Extremity Arterial Disease. In Endovascular Therapy: Principles of Peripheral Interventions(pp 186-205). Oxford, UK: Blackwell Science.
- 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.More infoThe 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.
- 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). Risk factors and outcomes of blood transfusions in adrenalectomy. The Journal of surgical research, 199(2), 505-11.More infoBlood 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.
- 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.More infoNeuroendocrine 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).
- 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.More infoThe 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.More infoCervical hematoma can be a potentially fatal complication after thyroidectomy, but its risk factors and timing remain poorly understood.
- Hannallah, J., Hannallah, J., Rose, J., Rose, J., Guerrero, M. A., & Guerrero, M. A. (2013). Comprehensive literature review: recent advances in diagnosing and managing patients with poorly differentiated thyroid carcinoma. International journal of endocrinology, 2013.More infoPoorly 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., Korovin, L. N., Guerrero, M. A., & 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.More infoThe 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.More infoThyroid 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., Rose, J., Wertheim, B. C., Wertheim, B. C., Guerrero, M. A., & 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.More infoObjective: 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., Venkat, R., Guerrero, M. A., & Guerrero, M. A. (2013). Recent advances in the surgical treatment of differentiated thyroid cancer: a comprehensive review. The Scientific World Journal, 2013.More infoDifferentiated 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., Rose, J., Wertheim, B. C., Wertheim, B. C., Guerrero, M. A., & 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.More infoThe 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., Safavi, A., Vijayasekaran, A., Vijayasekaran, A., Guerrero, M. A., & Guerrero, M. A. (2012). New insight into the treatment of advanced differentiated thyroid cancer. Journal of Thyroid Research, 2012.More infoThe 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.
- 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.More infoTo 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. A. (2012). A rare finding of an ectopic parathyroid gland within a cervical thymic cyst presenting as a lateral neck mass. Am Surg, 78(3), 171-2.
- 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.More infoApproximately 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.More infoThe 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.More infoMedullary 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.More infoThe 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.
- Guerrero, M. A. (2010). Cryopreservation of parathyroid glands. International Journal of Endocrinology.More infoThe 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.More infoAdrenocortical 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., Rahbari, R., Mathur, A., Kitano, M., Shen, W., Duh, Q., Clark, O., & Kebebew, E. (2011). Prospective Randomized Trial of Ligasure Versus Harmonic Hemostasis Technique in Thyroidectomy. Ann Surgical Oncology, 18(4), 1023-1027.
- 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.More infoIntraoperative 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.More infoHürthle 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.More infoSerum 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.More infoPheochromocytomas 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.More infoTo 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.More infoAlthough 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.More infoElectronic 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.More infoFamilial 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.More infoAdrenocortical 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.More infoThere 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.More infoParathyroid 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.
- 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.More infoWe 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.More infoThe 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.More infoAnastomotic 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.More infoEmerging 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.More infoCarotid 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.More infoExtracranial 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.
- 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.More infoCarotid 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., 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.More infoCarotid 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.More infoWe 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.More infoCarotid 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., & Grau, A. (2003). A Case Report of Stromal Overgrowth in a Malignant Cystosarcoma Phyllodes Tumor of the Breast. Surgical Oncology, 12(1), 27-37.
- 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). 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. (2010, October 23-30). Neuroendocrine tumors of the pancreas. Internal 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. (2017, December). Endocrine Quiz. The SCORE Portal.
- Guerrero, M. A. (2017, October). Thyroid Quiz. The SCORE Portal.
- 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.
- 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., 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.
- 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., 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, 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., 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.
- 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.