Randi Lassiter

Racial disparities in the use of laparoscopic surgery to treat colonic diverticulitis Are not fully explained by socioeconomics or disease complexity

BACKGROUND Several studies have demonstrated favorable outcomes for laparoscopic surgery over open surgery for the treatment of diverticular disease. This study was designed to analyze the relationship between race, socioeconomic status and the use of laparoscopy to address diverticulitis. METHODS A retrospective analysis of 53,054 diverticulitis admissions was performed using data from the 2009-2013 National Inpatient Sample (NIS). The primary outcome was the use of laparoscopic versus open colectomy. Bivariate analysis and multivariable logistic regression were used to determine the raw and adjusted odds by race, insurance status, and median household income. RESULTS Overall, 41.6% of colectomies involved the use of laparoscopy. Black patients were 19% less likely than White patients to undergo laparoscopic surgery. Hispanic patients were no more or less likely to undergo laparoscopic colectomy. Lacking private insurance was a strong predictor of undergoing open surgery. Lower income patients were 33% less likely to receive minimally invasive colectomies. CONCLUSIONS These results demonstrate disparities in surgical treatment. Further research is warranted to understand and ameliorate treatment differences which can contribute to outcome disparities.

A model of acute renal allograft rejection in outbred Yorkshire piglets.

Pigs represent a desirable animal model for the study of rejection in kidney transplantation with inbred Yucatan miniature swine (YMS) the most commonly studied strain due to well defined swine leukocyte antigen (SLA) genotypes. However, limitations to YMS may include cost and availability. Outbred Yorkshire pigs are widely available and significantly cheaper than YMS. Recent advances in SLA genotyping have allowed its application to outbred strains. On this basis, we theorized that Yorkshire pigs would be a viable alternative to YMS for the study of rejection in kidney transplantation. To address this question, we performed auto (Auto) and allotransplants (Allo) in 24 Yorkshire pigs, and assessed SLA genotypes and acute rejection after 72h. At sacrifice, and when compared to autotransplants, allotransplants had significant elevations in serum creatinine (8.4±1.3 vs 2.8±2.0mg/dL for Allo vs autotransplants, respectively) and BUN (61±9 vs 19.2±15mg/dL for Allo vs autotransplants, respectively). Warm ischemia times between the two groups did not differ (24±2.3 vs 26.4±1.4min for Auto vs Allo, respectively). There were 16 distinct SLA haplotypes identified from pigs undergoing allotransplantion, no matched donor-recipient pairs, and all allografts demonstrated rejection. Type IIA cellular rejection (Banff) was the most common. One allograft demonstrated hyperacute rejection due a blood group incompatibility. Histologically, the expression of regulatory Tcells and dendritic cells was increased in allografts. These data suggest that Yorkshire pigs may be a useful model for the study of acute rejection in experimental kidney transplantation.

Feasibility and Benefit of Incorporating a Multimedia Cadaver Laboratory Training Program into a Didactics Curriculum for Junior and Senior Surgical Residents

OBJECTIVE As operative experience in general surgery decreases and work hour limitations increase there is less exposure of surgical residents to advanced vascular and trauma exposures. Many institutions have demonstrated benefits of cadaver laboratory courses. We have incorporated a multimedia cadaver laboratory course into our general surgery residency didactics curriculum with the objective to demonstrate a benefit of the program as well as the feasibility of incorporation. STUDY DESIGN This is a prospective study at a tertiary care institution including general surgery residents within our residency program. A curriculum was designed, requiring residents to complete multimedia learning modules before both a trauma cadaver laboratory and vascular exposure cadaver laboratory. Outcome measures included self-efficacy/confidence (precourse and postcourse 5-point Likert surveys), knowledge (net performance on precourse and postcourse multiple choice examinations), and resident perception of the curriculum (postcourse 5-point Likert survey). Data were analyzed using ANOVA paired t-tests. RESULTS For the vascular cadaver laboratory, resident knowledge improved overall from an average of 41.2% to 50.0% of questions correct (p = 0.032) and self-efficacy/confidence improved by 0.59 from 1.52 to 2.11 out of 5 (p = 0.009). Median confidence is 1.37 out of 5 and 2.32 out of 5, before and after course, respectively. Wilcoxon nonparametric test reveals a p = 0.011. Residents perception of the usefulness of the laboratory evaluation was 3.85 out 5. There were 85.71% agreed that the laboratory is useful and 14.29% were disagree. The Z-score is -0.1579 (means 0.1579 standard deviations a score of 3.85 below the benchmark). The percentile rank is 56.27%. The coefficient of variation is 24.68%. For the trauma cadaver laboratory, resident knowledge improved overall from an average of 55.89% to 66.17% of questions correct (p = 0.001) and self-efficacy/confidence improved by 0.75 from 1.68 out of 5 to 2.43 out of 5 (p = 0.011). Median confidence level is 1.41 out of 5 before the training course and 2.64 out of 5 after the training course. Wilcoxon signed rank test gives a p value of 0.008. Residents perception of the usefulness of the laboratory evaluation was 3.94 out 5. There were 72.22% agreed that the laboratory is useful and 27.78% were neutral. The Z-score is -0.098 (means 0.098 standard deviations a score of 3.94 below the benchmark). The percentile rank is 53.90%. The coefficient of variation is 15.48%. CONCLUSIONS Incorporating a multimedia cadaver laboratory into a residency education didactics curriculum was both feasible and beneficial for resident education. We demonstrate an improvement in knowledge and self efficacy/confidence following both cadaver laboratory courses.

Regulation of indoleamine 2,3 dioxygenase and its role in a porcine model of acute kidney allograft rejection

In kidney transplantation acute allograft rejection is the most common cause of late allograft loss. Changes in indoleamine 2,3 dioxygenase (IDO) activity, which catabolizes the degradation of tryptophan to kynurenine, may predict rejection. However, exogenous IDO is immunosuppressive in rodent kidney transplantation. Thus, the increase in IDO activity observed in acute allograft rejection is insufficient to prevent rejection. To address this question, we assessed the regulation of IDO and its role in acute rejection in a porcine model of kidney transplant. In tissue samples from rejecting kidney allografts, we showed a 13-fold increase in IDO gene transcription and 20-fold increase in IDO enzyme activity when compared with autotransplanted kidneys. Allografts also demonstrated an over fourfold increase in tissue interferon (IFN)-γ, with marked increases in tumor necrosis factor (TNF)-α, TNF-β and interleukin 1β. Gene transcription and protein levels of kynurenine 3-monooxygenase (KMO) were decreased. KMO generates the immunosuppressive kynurenine, 3-hydroxykynurenine. The results of these studies demonstrate a clear association between rejection and increased allograft IDO expression, likely driven in part by IFN-γ and facilitated by other cytokines of the allogeneic response. Moreover, the loss of downstream enzymatic activity in the IDO metabolic pathway may suggest novel mechanisms for the perpetuation of rejection.

Laparoscopy-Assisted PEC Tubes: A Novel Treatment for Sigmoid Volvulus

Introduction: In the United States, sigmoid volvulus is frequently seen in the elderly and neurologically impaired, driving a search for less invasive but effective treatments that may obviate the need for resection. This case study describes a novel technique for sigmoidopexy: a modified endoscopic approach for percutaneous endoscopic colostomy (PEC) tube placement in combination with laparoscopy for safety. Case Description: This is a case study reporting a novel technique. The subject was a 55-year-old man with a history of longstanding constipation and recurrent sigmoid volvulus. Because of religious beliefs, the family refused any surgical procedures requiring bowel resection. Thus, alternative methods for definitive treatment were sought. The patient underwent laparoscopic assisted PEC tube placement with placement of three colostomy tubes for sigmoidopexy. The procedure was tolerated well, and the patient had an uneventful postoperative course. With persistent symptoms of constipation and dysmotility, the colon could be vented and irrigated via the colostomy tubes. Two years after surgery the patient has all 3 PEC tubes in place without complication or recurrence of sigmoid volvulus. Conclusion: PEC tubes have been used for sigmoidopexy with various levels of success in the treatment of recurrent volvulus, but laparoscopic assistance in placement of 3 PEC tubes has not been documented. Laparoscopic assistance allows for reduction of volvulus and decreases complications associated with PEC tube placement. This case demonstrates a novel, safe technique for the treatment of sigmoid volvulus.