Bio

Clinical Focus


  • GI Oncology
  • Hepatobiliary and Pancreas Surgery
  • Minimally Invasive Surgery
  • General Surgery

Academic Appointments


Professional Education


  • Internship:UCSF - East Bay Surgery ProgramCA
  • Residency:Stanford Hospital and Clinics - Dept of SurgeryCA
  • Fellowship:Cleveland Clinic FoundationOH
  • Fellowship:Stanford University School of MedicineCA
  • Medical Education:Drexel University College of Medicine (2005) PA
  • Board Certification, American Board of Surgery, General Surgery (2013)

Research & Scholarship

Current Research and Scholarly Interests


Technical aspects of minimally invasive pancreatic and liver surgery
Minimally invasive strategies for the management of pancreatic necrosis
Management of severe acute pancreatitis – academic vs community treatment
Multidisciplinary treatment of HCC; institutional barriers to appropriate referral/ care
Endocrine/exocrine insufficiency after pancreatectomy; volumetric assessment
Natural history and management of pancreatic cysts

Publications

Journal Articles


  • Cyst Fluid Glucose is Rapidly Feasible and Accurate in Diagnosing Mucinous Pancreatic Cysts. American journal of gastroenterology Zikos, T., Pham, K., Bowen, R., Chen, A. M., Banerjee, S., Friedland, S., Dua, M. M., Norton, J. A., Poultsides, G. A., Visser, B. C., Park, W. G. 2015; 110 (6): 909-914

    Abstract

    Better diagnostic tools are needed to differentiate pancreatic cyst subtypes. A previous metabolomic study showed cyst fluid glucose as a potential marker to differentiate mucinous from non-mucinous pancreatic cysts. This study seeks to validate these earlier findings using a standard laboratory glucose assay, a glucometer, and a glucose reagent strip.Using an IRB-approved prospectively collected bio-repository, 65 pancreatic cyst fluid samples (42 mucinous and 23 non-mucinous) with histological correlation were analyzed.Median laboratory glucose, glucometer glucose, and percent reagent strip positive were lower in mucinous vs. non-mucinous cysts (P<0.0001 for all comparisons). Laboratory glucose<50 mg/dl had a sensitivity of 95% and a specificity of 57% (LR+ 2.19, LR- 0.08). Glucometer glucose<50 mg/dl had a sensitivity of 88% and a specificity of 78% (LR+ 4.05, LR- 0.15). Reagent strip glucose had a sensitivity of 81% and a specificity of 74% (LR+ 3.10, LR- 0.26). CEA had a sensitivity of 77% and a specificity of 83% (LR+ 4.67, LR- 0.27). The combination of having either a glucometer glucose<50 mg/dl or a CEA level>192 had a sensitivity of 100% but a low specificity of 33% (LR+ 1.50, LR- 0.00).Glucose, whether measured by a laboratory assay, a glucometer, or a reagent strip, is significantly lower in mucinous cysts compared with non-mucinous pancreatic cysts.

    View details for DOI 10.1038/ajg.2015.148

    View details for PubMedID 25986360

  • Hepato-pancreatectomy: how morbid? Results from the national surgical quality improvement project. HPB : the official journal of the International Hepato Pancreato Biliary Association Tran, T. B., Dua, M. M., Spain, D. A., Visser, B. C., Norton, J. A., Poultsides, G. A. 2015

    Abstract

    Simultaneous resection of both the liver and the pancreas carries significant complexity. The objective of this study was to investigate peri-operative outcomes after a synchronous hepatectomy and pancreatectomy (SHP).The American College of Surgeons National Surgical Quality Improvement Project database was queried to identify patients who underwent SHP. Resections were categorized as '< hemihepatectomy', '≥ hemihepatectomy' (hemihepatectomy and trisectionectomy), 'PD' (pancreaticoduodenectomy and total pancreatectomy) and 'distal' (distal pancreatectomy and enucleation).From 2005 to 2013, 480 patients underwent SHP. Patients were stratified based on the extent of resection: '< hemihepatectomy + distal (n = 224)', '≥ hemihepatectomy + distal' (n = 49), '< hemihepatectomy + PD' (n = 83) and '≥ hemihepatectomy + PD' (n = 24). Although the first three groups had a reasonable and comparable safety profile (morbidity 33-51% and mortality 0-6.6%), the '≥ hemihepatectomy + PD' group was associated with an 87.5% morbidity (organ space infection 58.3%, re-intubation 12.5%, reoperation 25% and septic shock 25%), 8.3% 30-day mortality and 18.2% in-hospital mortality.A synchronous hemihepatectomy (or trisectionectomy) with PD remains a highly morbid combination and should be reserved for patients who have undergone extremely cautious selection.

    View details for DOI 10.1111/hpb.12426

    View details for PubMedID 26058463

  • Prognostic relevance of lymph node ratio and total lymph node count for small bowel adenocarcinoma. Surgery Tran, T. B., Qadan, M., Dua, M. M., Norton, J. A., Poultsides, G. A., Visser, B. C. 2015; 158 (2): 486-93

    Abstract

    Nodal metastasis is a known prognostic factor for small bowel adenocarcinoma. The goals of this study were to evaluate the number of lymph nodes (LNs) that should be retrieved and the impact of lymph node ratio (LNR) on survival.Surveillance, Epidemiology, and End Results was queried to identify patients with small bowel adenocarcinoma who underwent resection from 1988 to 2010. Survival was calculated with the Kaplan-Meier method. Multivariate analysis identified predictors of survival.A total of 2,772 patients underwent resection with at least one node retrieved, and this sample included equal numbers of duodenal (n = 1,387) and jejunoileal (n = 1,386) adenocarcinomas. There were 1,371 patients with no nodal metastasis (N0, 49.4%), 928 N1 (33.5%), and 474 N2 (17.1%). The median numbers of LNs examined for duodenal and jejunoileal cancers were 9 and 8, respectively. Cut-point analysis demonstrated that harvesting at least 9 for jejunoileal and 5 LN for duodenal cancers resulted in the greatest survival difference. Increasing LNR at both sites was associated with decreased overall median survival (LNR = 0, 71 months; LNR 0-0.02, 35 months; LNR 0.21-0.4, 25 months; and LNR >0.4, 16 months; P < .001). Multivariate analysis confirmed number of LNs examined, T-stage, LN positivity, and LNR were independent predictors of survival.LNR has a profound impact on survival in patients with small bowel adenocarcinoma. To achieve adequate staging, we recommend retrieving a minimum of 5 LN for duodenal and 9 LN for jejunoileal adenocarcinomas.

    View details for DOI 10.1016/j.surg.2015.03.048

    View details for PubMedID 26013988

  • Severe acute pancreatitis in the community: confusion reigns. The Journal of surgical research Dua, M. M., Worhunsky, D. J., Tran, T. B., Rumma, R. T., Poultsides, G. A., Norton, J. A., Park, W. G., Visser, B. C. 2015

    Abstract

    The management of acute pancreatitis (AP) has evolved through enhanced understanding of the disease. Despite several evidence-based practice guidelines for AP, our hypothesis is that many hospitals still use historical treatments rather than adhere to the current guidelines, which have demonstrated shorter hospital stays, decreased infectious complications, decreased morbidity, and decreased mortality.Seventy-eight patients transferred to our institution with AP from 2010-2014 were retrospectively studied to compare pretransfer versus posttransfer adherence to current practice guidelines. Primary measures included use of antibiotics (abx), enteral nutrition, drainage of asymptomatic pseudocysts, and interventions for necrosis in the early phase (<4 wk).Pretransfer, abx were given to 51 patients; however, posttransfer, abx were discontinued in 33 patients and started in 6 patients within 24 h of admission (pretransfer versus posttransfer abx, 51 versus 24, P < 0.001). Empiric abx for AP were used in 36 patients pretransfer versus 9 patients posttransfer (P < 0.001). Patients were initially nil per os or on total parenteral nutrition in 89%; this was reduced to 17% within 72 h by starting a diet or enteric feeds (pretransfer versus posttransfer feeding, 9 versus 65 patients, P < 0.001). Fifteen transfer patients had pseudocysts that were believed to "require drainage"; five patients received intervention but >4 wk from initial episode of AP. Pretransfer, five patients had pancreatic debridement in the early phase, which resulted in prolonged postoperative length of stay compared with eight patients requiring debridement, which were delayed (early versus late, 56 versus 16 d, P < 0.05).There is still great confusion in the treatment of AP in community hospitals. Primary principles in the care of these patients are not routinely followed despite established guidelines. Increased dissemination is required to prevent lengthy hospitalizations and long-term morbidity.

    View details for DOI 10.1016/j.jss.2015.04.054

    View details for PubMedID 25972313

  • Laparoscopic Transgastric Necrosectomy for the Management of Pancreatic Necrosis JOURNAL OF THE AMERICAN COLLEGE OF SURGEONS Worhunsky, D. J., Qadan, M., Dua, M. M., Park, W. G., Poultsides, G. A., Norton, J. A., Visser, B. C. 2014; 219 (4): 735-743
  • Getting the dead out: modern treatment strategies for necrotizing pancreatitis. Digestive diseases and sciences Dua, M. M., Worhunsky, D. J., Amin, S., Louie, J. D., Park, W. G., Triadafilopoulos, G., Visser, B. C. 2014; 59 (9): 2069-2075

    View details for DOI 10.1007/s10620-014-3153-z

    View details for PubMedID 24748229

  • Laparoscopic spleen-preserving distal pancreatectomy: the technique must suit the lesion. Journal of gastrointestinal surgery Worhunsky, D. J., Zak, Y., Dua, M. M., Poultsides, G. A., Norton, J. A., Visser, B. C. 2014; 18 (8): 1445-1451

    Abstract

    Splenic preservation is currently recommended during minimally invasive surgery for benign tumors of the distal pancreas. The aim of this study was to evaluate the outcomes of patients undergoing laparoscopic spleen-preserving distal pancreatectomy, with particular attention paid to the technique used for spleen preservation (splenic vessel ligation vs preservation). A review of consecutive patients who underwent laparoscopic distal pancreatectomy with the intention of splenic preservation was conducted. Patient demographics, operative data, and outcomes were collected and analyzed. Fifty-five consecutive patients underwent laparoscopic distal pancreatectomy with the intention of splenic preservation; 5 required splenectomy (9 %). Of the remaining 50 patients, 31 (62 %) had splenic vessel ligation, and 19 (38 %) had vessel preservation. Patient demographics and tumor size were similar. The vessel ligation group had significantly more pancreas removed (95 vs 52 mm, P < 0.001) and longer operative times (256 vs 201 min, P = 0.008). Postoperative outcomes, complication rates, and splenic viability were similar between groups. Laparoscopic spleen-preserving distal pancreatectomy is a safe operation with a high rate of success (91 %). Vessel ligation was the chosen technical strategy for lesions that required resection of a greater length of pancreas. We found no advantage to either technique with respect to outcomes and splenic preservation. Operative approach should reflect technical considerations including location in the pancreas.

    View details for DOI 10.1007/s11605-014-2561-x

    View details for PubMedID 24939598

  • Intraoperative Imaging of Nipple Perfusion Patterns and Ischemic Complications in Nipple-Sparing Mastectomies ANNALS OF SURGICAL ONCOLOGY Wapnir, I., Dua, M., Kieryn, A., Paro, J., Morrison, D., Kahn, D., Meyer, S., Gurtner, G. 2014; 21 (1): 100-106

    Abstract

    Nipple-sparing mastectomies (NSM) have gained acceptance in the field of breast oncology. Ischemic complications involving the nipple-areolar complex (NAC) occur in 3-37 % of cases. Skin perfusion can be monitored intraoperatively using indocyanine green (IC-GREEN™, ICG) and a specialized infrared camera-computer system (SPY Elite™). The blood flow pattern to the breast skin and the NAC were evaluated and a classification scheme was developed.Preincision baseline and postmastectomy skin perfusion studies were performed intraoperatively using 3 mL of ICG. The pattern of arterial blood inflow was classified according to whether perfusion appeared to originate predominantly from the underlying breast tissue (V1), the surrounding skin (V2), or a combination of V1 and V2 (V3). Ischemia, resection, or delayed complications of NAC were recorded.Thirty-nine breasts were interrogated. Seven (18 %) demonstrated a V1 pattern, 18 (46 %) a V2 pattern, and 14 (36 %) a V3 pattern. Seven (18 %) NACs were removed; six intraoperatively and the seventh in a delayed fashion. Notably, five of the seven resected NACs had a V1 pattern. Overall, 71 % of all V1 cases demonstrated profound ischemic changes by intraoperative clinical judgment and SPY imaging. The rates of resection of the NAC differed significantly between perfusion patterns (Fisher's exact test, p = 0.0003).Three perfusion patterns for the NAC are defined. The V1 pattern had the highest rate of NAC ischemia in NSM. Imaging NAC and skin perfusion during NSMs is a useful adjunctive tool with potential to direct placement of mastectomy incisions and minimize ischemic complications.

    View details for DOI 10.1245/s10434-013-3214-0

    View details for Web of Science ID 000332671700018

    View details for PubMedID 24046104

  • Non-MalIg(G4)nant Biliary Obstruction: When the Pill Is Mightier than the Knife. Digestive diseases and sciences Dua, M. M., Qadan, M., Lutchman, G. A., Park, W. G., Triadafilopoulos, G., Visser, B. C. 2014

    View details for DOI 10.1007/s10620-014-3329-6

    View details for PubMedID 25138904

  • Early Vein Reconstruction and Right-to-Left Dissection for Left-Sided Pancreatic Tumors with Portal Vein Occlusion. Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract Cloyd, J. M., Dua, M. M., Visser, B. C. 2014

    Abstract

    Large left-sided pancreatic tumors are frequently associated with portal vein (PV) and/or superior mesenteric vein (SMV) occlusion. Traditionally, vein reconstruction is deferred until after removal of the tumor. However, division of venous collaterals, as is done in a typical left-to-right fashion, leads to progressive portal hypertension and increased risk of variceal hemorrhage during the dissection. Conversely, early PV/SMV resection and reconstruction restores mesenteric-portal flow and decompresses varices, thereby enabling a safer and easier right-to-left pancreatic resection. This "How I Do It" report describes the technique and advantages of a "reconstruction-first" approach for large left-sided pancreatic tumors with venous involvement and left-sided portal hypertension.

    View details for DOI 10.1007/s11605-014-2616-z

    View details for PubMedID 25091848

  • More with Less: Pancreas-Preserving Total Duodenectomy. Digestive diseases and sciences Qadan, M., Dua, M., Worhunsky, D., Triadafilopoulos, G., Visser, B. 2014

    View details for DOI 10.1007/s10620-014-3331-z

    View details for PubMedID 25138905

  • Extracorporeal Pringle for laparoscopic liver resection. Surgical endoscopy Dua, M. M., Worhunsky, D. J., Hwa, K., Poultsides, G. A., Norton, J. A., Visser, B. C. 2014

    Abstract

    A primary concern during laparoscopic liver resection (lapLR) is hemorrhage during parenchymal transection. Intermittent pedicle clamping is an effective method to minimize blood loss during open liver surgery; however, inflow occlusion techniques are challenging to reproduce during laparoscopy. The purpose of this study is to describe the safety and efficacy of a facile method for Pringle maneuver during lapLR.154 patients who underwent lapLR from 2007 to 2013 were retrospectively reviewed. For Pringle, the hepatoduodenal ligament is encircled with an umbilical tape which is externalized through a flexible Rumel tourniquet running alongside a port used for the operation. The internal end of the catheter is close to the pedicle and the external end is extracorporeal, allowing for easy external occlusion. Patients who underwent Pringle Maneuver (PM, n = 88) were compared to patients who had "No Occlusion" (NO, n = 66) with respect to patient characteristics, operative outcomes, changes in postoperative liver function, and complications.Annual placement of the tourniquet and vascular occlusion increased from 35.7 to 82.8 % (p = 0.004) and 21.4 to 62.1 % (p = 0.02), respectively. Median occlusion time was 24 min (IQR 15-34.3, min 5, max 70). Peak transaminase levels were comparable between groups (AST 298 ± 32 vs 405 ± 47 U/L, p = 0.15; ALT 272 ± 27 vs 372 ± 34 U/L, p = 0.14, NO and PM, respectively). Postoperative transaminase and bilirubin levels for both groups were not significantly different with similar recovery to baseline. Subgroup analysis of cirrhotic patients who underwent Pringle demonstrated similar transaminase profiles compared to non-cirrhotic patients. There were two conversions (1.3 %) and postoperative 30-day mortality was 0.65 %.Extracorporeal tourniquet placement in lapLR is a quick and safe method of gaining control for inflow occlusion. Routine adoption of laparoscopic Pringle maneuver facilitates low conversion rates without liver injury.

    View details for DOI 10.1007/s00464-014-3801-6

    View details for PubMedID 25159645

  • Cardiac metastases and tumor embolization: A rare sequelae of primary undifferentiated liver sarcoma. International journal of surgery case reports Dua, M. M., Cloyd, J. M., Haddad, F., Beygui, R. E., Norton, J. A., Visser, B. C. 2014; 5 (12): 927-931

    Abstract

    Primary hepatic sarcomas are uncommon malignant neoplasms; prognostic features, natural history, and optimal management of these tumors are not well characterized.This report describes the management of a 51-year-old patient that underwent a right trisectionectomy for a large hepatic mass found to be a liver sarcoma on pathology. He subsequently developed tumor emboli to his lungs and was discovered to have cardiac intracavitary metastases from his primary tumor. The patient underwent cardiopulmonary bypass and resection of the right-sided heart metastases to prevent further pulmonary sequela of tumor embolization.The lack of distinguishing symptoms or imaging characteristics that clearly define hepatic sarcomas makes it challenging to achieve a diagnosis prior to pathologic examination. Metastatic spread is frequently to the lung or pleura, but very rarely seen within the heart. Failure to recognize cardiac metastatic disease will ultimately lead to progressive tumor embolization and cardiac failure if left untreated.The most effective therapy for primary liver sarcomas is surgery; radical resection should be performed if possible given the aggressive nature of these tumors to progress and metastasize.

    View details for DOI 10.1016/j.ijscr.2014.10.004

    View details for PubMedID 25460438

  • Laparoscopic Bariatric Surgery Can Be Performed Through a Single Incision: A Comparative Study. Obesity surgery Rogula, T., Daigle, C., Dua, M., Shimizu, H., Davis, J., Lavryk, O., Aminian, A., Schauer, P. 2014

    Abstract

    The application of single-incision laparoscopic surgery (SILS) in bariatric patients has been limited to less complex procedures. We evaluated the short-term outcomes of SILS sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB), compared to a group of well-established minimally invasive techniques.Twenty-eight morbidly obese patients who underwent SILS SG (n = 14) and RYGB (n = 14) were compared to a matched control group composed of 28 cases of conventional laparoscopic surgery (CLS). A single vertical 2.5-3-cm intra-umbilical incision, three-ports placed trans-fascially, and a liver suspension technique were used to perform SILS.Both groups were comparable in terms of age (p = 0.96), gender (p = 1.0), type of procedure (p = 1.0), and number of comorbidities (p = 0.63). Two (7 %) SILS patients required placement of one additional port, and no conversions to CLS or open surgery were needed. The estimated blood loss (p = 0.48), operative time (p = 0.33), length of hospital stay (p = 0.79), overall 90-day perioperative complication rate (p = 1.0), and short-term weight loss (p = 0.53) were comparable between the two groups. In terms of pain control, the frequency of patient-controlled analgesia use in both groups was similar. However, the pain score (assessed by visual analog scale) was significantly less for SILS patients on postoperative days 1 (5.0 ± 2.1 vs. 6.5 ± 1.8; p = 0.007) and 2 (4.0 ± 2.0 vs. 5.1 ± 2.4; p = 0.49). Cosmetic satisfaction with the scar was high in the SILS group. No patients required reoperation or readmission during the 90 days after surgery.SILS is feasible in carefully selected bariatric patients and results in short-term outcomes comparable to those observed after CLS. Improved pain and cosmesis are potential benefits of SILS.

    View details for DOI 10.1007/s11695-014-1291-1

    View details for PubMedID 24817374

  • RGD-Conjugated Human Ferritin Nanoparticles for Imaging Vascular Inflammation and Angiogenesis in Experimental Carotid and Aortic Disease MOLECULAR IMAGING AND BIOLOGY Kitagawa, T., Kosuge, H., Uchida, M., Dua, M. M., Iida, Y., Dalman, R. L., Douglas, T., McConnell, M. V. 2012; 14 (3): 315-324

    Abstract

    Inflammation and angiogenesis are important contributors to vascular disease. We evaluated imaging both of these biological processes, using Arg-Gly-Asp (RGD)-conjugated human ferritin nanoparticles (HFn), in experimental carotid and abdominal aortic aneurysm (AAA) disease.Macrophage-rich carotid lesions were induced by ligation in hyperlipidemic and diabetic FVB mice (n?=?16). AAAs were induced by angiotensin II infusion in apoE(-/-) mice (n=10). HFn, with or without RGD peptide, was labeled with Cy5.5 and injected intravenously for near-infrared fluorescence imaging.RGD-HFn showed significantly higher signal than HFn in diseased carotids and AAAs relative to non-diseased regions, both in situ (carotid: 1.88?±?0.30 vs. 1.17?±?0.10, p?=?0.04; AAA: 2.59?±?0.24 vs. 1.82?±?0.16, p?=?0.03) and ex vivo. Histology showed RGD-HFn colocalized with macrophages in carotids and both macrophages and neoangiogenesis in AAA lesions.RGD-HFn enhances vascular molecular imaging by targeting both vascular inflammation and angiogenesis, and allows more comprehensive detection of high-risk atherosclerotic and aneurysmal vascular diseases.

    View details for DOI 10.1007/s11307-011-0495-1

    View details for Web of Science ID 000303884400006

    View details for PubMedID 21638084

  • Bioluminescence and Magnetic Resonance Imaging of Macrophage Homing to Experimental Abdominal Aortic Aneurysms MOLECULAR IMAGING Miyama, N., Dua, M. M., Schultz, G. M., Kosuge, H., Terashima, M., Pisani, L. J., Dalman, R. L., McConnell, M. V. 2012; 11 (2): 126-134

    Abstract

    Macrophage infiltration is a prominent feature of abdominal aortic aneurysm (AAA) progression. We used a combined imaging approach with bioluminescence (BLI) and magnetic resonance imaging (MRI) to study macrophage homing and accumulation in experimental AAA disease. Murine AAAs were created via intra-aortic infusion of porcine pancreatic elastase. Mice were imaged over 14 days after injection of prepared peritoneal macrophages. For BLI, macrophages were from transgenic mice expressing luciferase. For MRI, macrophages were labeled with iron oxide particles. Macrophage accumulation during aneurysm progression was observed by in situ BLI and by in vivo 7T MRI. Mice were sacrificed after imaging for histologic analysis. In situ BLI (n ?=? 32) demonstrated high signal in the AAA by days 7 and 14, which correlated significantly with macrophage number and aortic diameter. In vivo 7T MRI (n ?=? 13) at day 14 demonstrated T?* signal loss in the AAA and not in sham mice. Immunohistochemistry and Prussian blue staining confirmed the presence of injected macrophages in the AAA. BLI and MRI provide complementary approaches to track macrophage homing and accumulation in experimental AAAs. Similar dual imaging strategies may aid the study of AAA biology and the evaluation of novel therapies.

    View details for DOI 10.2310/7290.2011.00033

    View details for Web of Science ID 000307645900004

    View details for PubMedID 22469240

  • Hyperglycemia limits experimental aortic aneurysm progression JOURNAL OF VASCULAR SURGERY Miyama, N., Dua, M. M., Yeung, J. J., Schultz, G. M., Asagami, T., Sho, E., Sho, M., Dalman, R. L. 2010; 52 (4): 975-983

    Abstract

    Diabetes mellitus (DM) is associated with reduced progression of abdominal aortic aneurysm (AAA) disease. Mechanisms responsible for this negative association remain unknown. We created AAAs in hyperglycemic mice to examine the influence of serum glucose concentration on experimental aneurysm progression.Aortic aneurysms were induced in hyperglycemic (DM) and normoglycemic models by using intra-aortic porcine pancreatic elastase (PPE) infusion in C57BL/6 mice or by systemic infusion of angiotensin II (ANG) in apolipoprotein E-deficient (ApoE(-/-)) mice, respectively. In an additional DM cohort, insulin therapy was initiated after aneurysm induction. Aneurysmal aortic enlargement progression was monitored with serial transabdominal ultrasound measurements. At sacrifice, AAA cellularity and proteolytic activity were evaluated by immunohistochemistry and substrate zymography, respectively. Influences of serum glucose levels on macrophage migration were examined in separate models of thioglycollate-induced murine peritonitis.At 14 days after PPE infusion, AAA enlargement in hyperglycemic mice (serum glucose ? 300 mg/dL) was less than that in euglycemic mice (PPE-DM: 54% ± 19% vs PPE: 84% ± 24%, P < .0001). PPE-DM mice also demonstrated reduced aortic mural macrophage infiltration (145 ± 87 vs 253 ± 119 cells/cross-sectional area, P = .0325), elastolysis (% residual elastin: 20% ± 7% vs 12% ± 6%, P = .0209), and neovascularization (12 ± 8 vs 20 ± 6 vessels/high powered field, P = .0229) compared with PPE mice. Hyperglycemia limited AAA enlargement after ANG infusion in ApoE(-/-) mice (ANG-DM: 38% ± 12% vs ANG: 61% ± 37% at day 28). Peritoneal macrophage production was reduced in response to thioglycollate stimulation in hyperglycemic mice, with limited augmentation noted in response to vascular endothelial growth factor administration. Insulin therapy reduced serum glucose levels and was associated with AAA enlargement rates intermediate between euglycemic and hyperglycemic mice (PPE: 1.21 ± 0.14 mm vs PPE-DM: 1.00 ± 0.04 mm vs PPE-DM + insulin: 1.14 ± 0.05 mm).Hyperglycemia reduces progression of experimental AAA disease; lowering of serum glucose levels with insulin treatment diminishes this protective effect. Identifying mechanisms of hyperglycemic aneurysm inhibition may accelerate development of novel clinical therapies for AAA disease.

    View details for DOI 10.1016/j.jvs.2010.05.086

    View details for Web of Science ID 000282660300023

    View details for PubMedID 20678880

  • Live Transference of Surgical Subspecialty Skills Using Telerobotic Proctoring to Remote General Surgeons JOURNAL OF THE AMERICAN COLLEGE OF SURGEONS Ereso, A. Q., Garcia, P., Tseng, E., Gauger, G., Kim, H., Dua, M. M., Victorino, G. P., Guy, T. S. 2010; 211 (3): 400-411

    Abstract

    Certain clinical environments, including military field hospitals or rural medical centers, lack readily available surgical subspecialists. We hypothesized that telementoring by a surgical subspecialist using a robotic platform is feasible and can convey subspecialty knowledge and skill to a remotely located general surgeon.Eight general surgery residents evaluated the effect of remote surgical telementoring by performing 3 operative procedures, first unproctored and then again when teleproctored by a surgical subspecialist. The clinical scenarios consisted of a penetrating right ventricular injury requiring suture repair, an open tibial fracture requiring external fixation, and a traumatic subdural hematoma requiring craniectomy. A robotic platform consisting of a pan-and-tilt camera with laser pointer attached to an overhead surgical light with integrated audio allowed surgical subspecialists the ability to remotely teleproctor residents. Performance was evaluated using an Operative Performance Scale. Satisfaction surveys were given after performing the scenario unproctored and again after proctoring.Overall mean performance scores were superior in all scenarios when residents were proctored than when they were not (4.30 +/- 0.25 versus 2.43 +/- 0.20; p < 0.001). Mean performance scores for individual metrics, including tissue handling, instrument handling, speed of completion, and knowledge of anatomy, were all superior when residents were proctored (p < 0.001). Satisfaction surveys showed greater satisfaction and comfort among residents when proctored. Proctored residents believed the robotic platform facilitated learning and would be feasible if used clinically.This study supports the use of surgical teleproctoring in guiding remote general surgeons by a surgical subspecialist in the care of a wounded patient in need of an emergency subspecialty operation.

    View details for DOI 10.1016/j.jamcollsurg.2010.05.014

    View details for Web of Science ID 000281708500014

    View details for PubMedID 20800198

  • Hyperglycemia modulates plasminogen activator inhibitor-1 expression and aortic diameter in experimental aortic aneurysm disease SURGERY Dua, M. M., Miyama, N., Azuma, J., Schultz, G. M., Sho, M., Morser, J., Dalman, R. L. 2010; 148 (2): 429-435

    Abstract

    Extracellular matrix degradation is a sentinel pathologic feature of abdominal aortic aneurysm (AAA) disease. Diabetes mellitus, a negative risk factor for AAA, may impair aneurysm progression through its influence on the fibrinolytic system. We hypothesize that hyperglycemia limits AAA progression through effects on endogenous plasminogen activator inhibitor-1 (PAI-1) levels and subsequent reductions in plasmin generation.Experimental AAAs were induced in diabetic and control mice via the intra-aortic elastase infusion method. Serial transabdominal high-frequency ultrasound examinations were performed to monitor aortic diameter following elastase infusion. Circulating PAI-1 and plasmin alpha2-antiplasmin (PAP) complex concentrations were determined by ELISA and local expression of PAI-1 levels was examined by RT-PCR and immunohistochemistry.Hyperglycemia was associated with reduced AAA diameter, increased plasma PAI-1 concentration and reduced plasmin generation. Aneurysmal aortic PAI-1 gene expression increased in parallel with plasma concentration, with peak expression occurring early after aneurysm initiation.Hyperglycemia increases PAI-1 expression and attenuates AAA diameter in experimental AAA disease. These results emphasize the role of the fibrinolytic pathway in AAA pathophysiology, and suggest a candidate mechanism for hyperglycemic inhibition of AAA disease.

    View details for DOI 10.1016/j.surg.2010.05.014

    View details for Web of Science ID 000280433200034

    View details for PubMedID 20561659

  • Hemodynamic Influences on abdominal aortic aneurysm disease: Application of biomechanics to aneurysm pathophysiology VASCULAR PHARMACOLOGY Dua, M. M., Dalman, R. L. 2010; 53 (1-2): 11-21

    Abstract

    "Atherosclerotic" abdominal aortic aneurysms (AAAs) occur with the greatest frequency in the distal aorta. The unique hemodynamic environment of this area predisposes it to site-specific degenerative changes. In this review, we summarize the differential hemodynamic influences present along the length of the abdominal aorta, and demonstrate how alterations in aortic flow and wall shear stress modify AAA progression in experimental models. Improved understanding of aortic hemodynamic risk profiles provides an opportunity to modify patient activity patterns to minimize the risk of aneurysmal degeneration.

    View details for DOI 10.1016/j.vph.2010.03.004

    View details for Web of Science ID 000278450300002

    View details for PubMedID 20347049

  • Lipoxin A(4) Attenuates Microvascular Fluid Leak During Inflammation JOURNAL OF SURGICAL RESEARCH Ereso, A. Q., Cureton, E. L., Cripps, M. W., Sadjadi, J., Dua, M. M., Curran, B., Victorino, G. P. 2009; 156 (2): 183-188

    Abstract

    The release of proinflammatory cytokines during inflammation disturbs the endothelial barrier and can initiate significant intravascular volume loss. Proinflammatory cytokines also induce the expression of anti-inflammatory mediators, such as lipoxin, which promote the resolution of inflammation. Our hypothesis is that lipoxin A(4) (LXA(4)) reverses the increased microvascular fluid leak observed during inflammatory conditions.Microvascular fluid leak (L(p)) was measured in rat mesenteric venules using a micro-cannulation technique. L(p) was measured under the following conditions: (1) LXA(4) (100 nM) alone (n = 5), (2) LXA(4) (100 nM) administered after endothelial hyperpermeability induced by a continuous perfusion of 10 nM platelet activating factor (PAF) (n = 5), (3) LXA(4) (100 nM) perfused after inflammation induced by a systemic bolus of 10 mg/kg lipopolysaccharide (LPS) (n = 5), and (4) LXA(4) (100 nM) perfused after LPS-induced inflammation during inhibition of c-Jun N-terminal kinase (n = 4).LXA(4) alone slightly increased L(p) from baseline (L(p)-baseline = 1.05 +/- 0.03, L(p)-LXA(4) = 1.55 +/- 0.04; P < 0.0001). PAF increased L(p) 4-fold (L(p)-baseline = 1.20 +/- 0.10, L(p)-PAF = 4.49 +/- 0.95; P < 0.0001). LXA(4) administration after PAF decreased L(p) 66% versus PAF alone (from 4.49 +/- 0.95 to 1.54 +/- 0.13; P = 0.0004). LPS-induced inflammation increased L(p) over 2-fold (L(p)-baseline = 1.05 +/- 0.03, L(p)-LPS = 2.27 +/- 0.13; P < 0.0001). LXA(4) administration after LPS decreased L(p) 42% versus LPS alone (from 2.27 +/- 0.13 to 1.31 +/- 0.05; P < 0.0001). The effect of c-Jun N-terminal kinase inhibition during LPS-induced inflammation attenuated the decrease in leak cause by LXA(4) by 51% (P = 0.0002).After either LPS or PAF, LXA(4) attenuated the intravascular volume loss caused by these inflammatory mediators. The activity of LXA(4) may be partly mediated by the c-Jun N-terminal kinase signaling pathway. These data support an anti-inflammatory role for LXA(4) and suggests a potential pharmacologic role for LXA(4) during inflammation.

    View details for DOI 10.1016/j.jss.2009.01.009

    View details for Web of Science ID 000270564300002

    View details for PubMedID 19524267

  • Usability of Robotic Platforms for Remote Surgical Teleproctoring TELEMEDICINE JOURNAL AND E-HEALTH Ereso, A. Q., Garcia, P., Tseng, E., Dua, M. M., Victorino, G. P., Guy, T. S. 2009; 15 (5): 445-453

    Abstract

    Military field hospitals and rural medical centers may lack surgical subspecialists. Robotic technology can enable proctoring of remotely located general surgeons by subspecialists. Our objective compared three proctoring platforms: (1) 6-degree-of-freedom (DOF) computer input devices controlling a camera and laser pointer mounted on robotic arms, (2) a computer mouse controlling a pan-tilt-zoom (PTZ) camera and robotic laser scanner, and (3) a computer pen/tablet controlling a PTZ-camera and robotic laser scanner. Our hypothesis was that a pen/tablet or mouse platform would be superior to the 6-DOF-input device platform. Five surgeons used each platform by simulating the creation of operative incisions. Qualitative (instrument handling, time, motion, spatial awareness) and quantitative performance (accuracy, speed) was assessed on a five-point scale. Each surgeon completed a satisfaction survey. Both mouse and pen/tablet had higher mean performance scores than the 6-DOF-input device in all quantitative (6-DOF = 1.7 +/- 0.8, mouse = 4.3 +/- 0.2, pen = 4.1 +/- 0.6; p < 0.001) and qualitative measures (6-DOF = 1.7 +/- 0.2, mouse = 4.8 +/- 0.0, pen = 4.6 +/- 0.1; p < 0.001). Handling, motion, and instrument awareness were superior with the mouse and pen/tablet versus 6-DOF-input devices (p < 0.0001). Speed and accuracy were also superior using the mouse or pen/tablet versus 6-DOF-input devices (p < 0.0001). Surgeons completed tasks faster using the mouse versus pen/tablet (p = 0.02). Satisfaction surveys revealed a preference for the mouse. This study demonstrates the superiority of a mouse or pen/tablet controlling a PTZ-camera and robotic laser scanner for remote surgical teleproctoring versus 6-DOF-input devices controlling a camera and laser pointer. Either a mouse or pen/tablet platform allows subspecialists to proctor remotely located surgeons.

    View details for DOI 10.1089/tmj.2008.0164

    View details for Web of Science ID 000267334300008

    View details for PubMedID 19548825

  • Identifying abdominal aortic aneurysm risk factors in postmenopausal women. Women's health (London, England) Dua, M. M., Dalman, R. L. 2009; 5 (1): 33-37

    Abstract

    Evaluation of: Lederle FA, Larson JC, Margolis KL et al.: Abdominal aortic aneurysm events in the Women's Health Initiative: cohort study. Br. Med. J. 337, A1724 (2008). A linked cohort study of 161,808 postmenopausal women aged 50-79 years enrolled in the Women's Health Initiative was conducted during which participants were followed for the incidence of abdominal aortic aneurysm repair or rupture. This study evaluated the association between potential risk factors and subsequent abdominal aortic aneurysm events in women. A total of 467 women reported a diagnosis of abdominal aortic aneurysm before entering the study or during participation, with 184 aneurysm-related events identified. Abdominal aortic aneurysm events were strongly associated with age and smoking and negatively associated with diabetes and baseline use of postmenopausal hormone supplementation. Previous studies investigating abdominal aortic aneurysm have focused primarily on men, with little reliable information available on women. This study contributes a large female cohort to provide better insight into gender-specific abdominal aortic aneurysm risks and disease associations.

    View details for DOI 10.2217/17455057.5.1.33

    View details for PubMedID 19102638

  • Evaluation of platybasia with MR imaging AMERICAN JOURNAL OF NEURORADIOLOGY Koenigsberg, R. A., Vakil, N., Hong, T. A., Htaik, T., Faerber, E., Maiorano, T., Dua, M., FARO, S., Gonzales, C. 2005; 26 (1): 89-92

    Abstract

    Platybasia, or abnormal obtuseness of the basal angle, was first measured on plain skull images. At present, evaluation of the brain and skull more commonly involves CT and MR imaging. We evaluated a new MR imaging method of evaluating platybasia.We retrospectively evaluated midline sagittal MR images in 200 adults and 50 children. The basal angle of the skull base was measured by using two methods: The standard MR imaging technique measured the angle formed by two lines-one joining the nasion and the center of the pituitary fossa connected by a line joining the anterior border of the foramen magnum and center of the pituitary fossa. The modified technique measured the angle formed by a line across the anterior cranial fossa and dorsum sellae connecting a line along the clivus.With the standard MR imaging technique, we obtained mean angles of 129 degrees +/- 6 degrees for adults and 127 degrees +/- 5 degrees for children, compared with 135.3 degrees (composite mean) in previous series. The modified technique produced values of 117 degrees +/- 6 degrees for adults and 114 degrees +/- 5 degrees for children, which were significantly lower that those of standard MR imaging and traditional radiography (P <.05).Both the standard and modified MR imaging techniques produced basal angles lower than those previously reported with standard radiography. The modified technique uses clearly featured landmarks that can be reproduced consistently on midline sagittal T1 images. This technique and its corresponding values can be used as the new standard for evaluating the basal angle.

    View details for Web of Science ID 000226729300021

    View details for PubMedID 15661707

Stanford Medicine Resources: