Decreasing Surgical Site Infection Associated with the Use of Circular Staplers During Roux-En-Y Gastric Bypass.

Background: Laparoscopic Roux-en-Y gastric bypass (LRYGB) has been established as a leading treatment of obesity. Surgical site infections (SSIs) remain the most common complication. Objective: To compare the incidence of SSIs before and after the implementation of our technique. Methods: Our intraoperative technique limits enteric contact with the abdominal wall through a wound protector at the end-to-end anastomosis stapler port site, with enteric retrieval with a specimen bag followed by betadine irrigation. We analyzed our SSIs outcomes before and after implementation of our technique in all RYGB and laparoscopic sleeve-to-bypass conversions at our institution performed by two providers between January 1, 2009 to December 31, 2011 and January 1, 2019 to December 31, 2021. We compared patient age, sex, body mass index, American Society of Anesthesiologists class; and comorbidities including hypertension, diabetes, and hyperlipidemia. The χ2, Fischer exact, Wilcoxon Rank Sum tests, and multivariate analysis were performed. Results: Four hundred twenty-nine patients underwent LRYGB and sleeve-to-bypass conversion during the two study periods. Group 1 (162 patients, 37.76%) all underwent RYGB. Group 2 (267 patients, 62.24%) of whom 199 underwent RYGB and 68 underwent a laparoscopic sleeve-to-bypass conversion. The SSI rate was 9.26% in Group 1 and 2.62% in Group 2 (p = 0.002514). Statistical significance was also noted for operating room time (137 min vs 123 min, p = 0.02) and hospital length of stay (2 - 3 interquartile range vs 1 - 2 interquartile range, p = 0.04). Conclusion: We propose a safe, reproducible technique that significantly reduces SSI rates during LRYGB.

Transversus abdominis plane block with liposomal bupivacaine and its effect on opiate use after weight loss surgery: a randomized controlled trial.

BACKGROUND: Liposomal bupivacaine (LB), as an extended-release local anesthetic, may provide lasting pain control and therefore decrease the need for narcotics in the immediate postoperative period. OBJECTIVES: The aim of this study was to evaluate whether transversus abdominis plane (TAP) block with LB decreased the use of postoperative narcotics compared with regular bupivacaine (RB) and no TAP block in patients undergoing weight loss procedures. SETTING: A large, metropolitan, university-affiliated, tertiary hospital. METHODS: Patients undergoing laparoscopic Roux-en-Y gastric bypass, sleeve gastrectomy, or sleeve-to-bypass conversion over 1 year were randomized to receive TAP block using LB, TAP block with RB, or no block in a double-blind, randomized controlled trial. The outcomes measured were postoperative use of opiates, pain score, length of stay, time to ambulation, and nausea. Data were analyzed using χ2 test and analysis of variance F test. RESULTS: Two hundred nineteen patients were included in the study. Fentanyl patient-controlled analgesia usage was not significantly different between the groups (LB 351.4 versus RB 360.7 versus no TAP block 353.9, P = .97) at 48 hours post operation. The pain scores (scale 1-10) were similar among the groups with the mean for the LB group at 4.3, and RB and no TAP block groups both at 4.7 (P = .35). The type of block or lack of block did not significantly impact the length of stay, time to ambulation, or presence of nausea. CONCLUSION: The LB TAP block did not significantly reduce the total opiate pain medication consumption nor did it reduce pain scores among bariatric surgery patients.

ß-Catenin in dendritic cells exerts opposite functions in cross-priming and maintenance of CD8+ T cells through regulation of IL-10.

Recent studies have demonstrated that ß-catenin in DCs serves as a key mediator in promoting both CD4(+) and CD8(+) T-cell tolerance, although how ß-catenin exerts its functions remains incompletely understood. Here we report that activation of ß-catenin in DCs inhibits cross-priming of CD8(+) T cells by up-regulating mTOR-dependent IL-10, suggesting blocking ß-catenin/mTOR/IL-10 signaling as a viable approach to augment CD8(+) T-cell immunity. However, vaccination of DC-ß-catenin(-/-) (CD11c-specific deletion of ß-catenin) mice surprisingly failed to protect them against tumor challenge. Further studies revealed that DC-ß-catenin(-/-) mice were deficient in generating CD8(+) T-cell immunity despite normal clonal expansion, likely due to impaired IL-10 production by ß-catenin(-/-) DCs. Deletion of ß-catenin in DCs or blocking IL-10 after clonal expansion similarly led to reduced CD8(+) T cells, suggesting that ß-catenin in DCs plays a positive role in CD8(+) T-cell maintenance postclonal expansion through IL-10. Thus, our study has not only identified mTOR/IL-10 as a previously unidentified mechanism for ß-catenin-dependent inhibition of cross-priming, but also uncovered an unexpected positive role that ß-catenin plays in maintenance of CD8(+) T cells. Despite ß-catenin's opposite functions in regulating CD8(+) T-cell responses, selectively blocking ß-catenin with a pharmacological inhibitor during priming phase augmented DC vaccine-induced CD8(+) T-cell immunity and improved antitumor efficacy, suggesting manipulating ß-catenin signaling as a feasible therapeutic strategy to improve DC vaccine efficacy.

Regulating mammalian target of rapamycin to tune vaccination-induced CD8(+) T cell responses for tumor immunity.

Vaccine strategies aimed at generating CD8(+) T cell memory responses are likely to show augmented efficacy against chronic challenges like tumor. The abundance in variety of memory CD8(+) T cells behooves development of vaccine strategies that generate distinct memory responses and evaluate them for tumor efficacy. In this study, we demonstrate the ability of a variety of rapamycin treatment regimens to regulate virus vaccination-induced CD8(+) T cell memory responses and tumor efficacy. Strikingly, a short course of high-dose, but not low-dose, rapamycin treatment transiently blocks viral vaccination-induced mammalian target of rapamycin activity in CD8(+) T cells favoring persistence and Ag-recall responses over type 1 effector maturation; however, prolonged high-dose rapamycin administration abrogated memory responses. Furthermore, a short course of high-dose rapamycin treatment generated CD8(+) T cell memory responses that were independent of IL-15 and IL-7 and were programmed early for sustenance and greater tumor efficacy. These results demonstrate the impact a regimen of rapamycin treatment has on vaccine-induced CD8(+) T cell responses and indicates that judicious application of rapamycin can augment vaccine efficacy for chronic challenges.