Weight Regain After Bariatric Surgery: Scope of the Problem, Causes, Prevention, and Treatment.

PURPOSE OF REVIEW: Although bariatric surgery is the most effective treatment of severe obesity, a proportion of patients experience clinically significant weight regain (WR) with further out from surgery. The purpose of this review is to summarize the prevalence, predictors, and causes of weight regain. RECENT FINDINGS: Estimating the prevalence of WR is limited by a lack of consensus on its definition. While anatomic failures such as dilated gastric fundus after sleeve gastrectomy and gastro-gastric fistula after Roux-en-Y gastric bypass can lead to WR, the most common causes appear to be dysregulated/maladaptive eating behaviors, lifestyle factors, and physiological compensatory mechanisms. To date, dietary, supportive, behavioral, and exercise interventions have not demonstrated a clinically meaningful impact on WR, and there is limited evidence for pharmacotherapy. Future studies should be aimed at better defining WR to begin to understand the etiologies. Additionally, there is a need for non-surgical interventions with demonstrated efficacy in rigorous randomized controlled trials for the prevention and reversal of WR after bariatric surgery.

Facilitating Success of the Early Stage Surgeon Scientist Trainee: Growing the Surgeon Scientist Pipeline.

OBJECTIVE: Surgeon scientists bring to bear highly specialized talent and innovative and impactful solutions for complicated clinical problems. Our objective is to inform and provide framework for early stage surgeon scientist training and support. SUMMARY OF BACKGROUND DATA: Undergraduate, medical student, and residency experiences impact the career trajectory of surgeon scientists. To combat the attrition of the surgeon scientist pipeline, interventions are needed to engage trainees and to increase the likelihood of success of future surgeon scientists. METHODS: A surgery resident writing group at an academic medical center, with guidance from faculty, prepared this guidance document for early stage surgeon scientist trainees with integration of the published literature to provide context. The publicly available National Institutes of Health RePORTER tool was queried to provide data salient to early stage surgeon scientist training. RESULTS: The educational path of surgeons and the potential research career entry points are outlined. Challenges and critical supportive elements needed to inspire and sustain progress along the surgeon scientist training path are detailed. Funding mechanisms available to support formal scientific training of early stage surgeon scientists are identified and obstacles specific to surgical careers are discussed. CONCLUSIONS: This guidance enhances awareness of essential education, communication, infrastructure, resources, and advocacy by surgery leaders and other stakeholders to promote quality research training in residency and to re-invigorate the surgeon scientist pipeline.

Hope on the horizon: promising novel therapies for necrotizing enterocolitis.

Necrotizing enterocolitis (NEC) remains among the most common and devastating diseases in neonates. Despite advances in neonatal clinical care, specific treatment strategies and diagnostic modalities remain lacking. As a result, morbidity and mortality remain high. Improved understanding of the pathogenesis of NEC has the potential for improved therapeutics. Some of the areas of research leading to promising discoveries include inhibition of Toll-like receptor signaling, modulation of vascular endothelial growth factor signal pathways, defining metabolomic alterations in NEC to discover potential biomarkers, probing for genetic predispositions to NEC susceptibility, determining mechanistic relations between anemia and NEC, and microflora modulation through the use of probiotics. All of these areas may represent novel promising approaches to the prevention and treatment of NEC. This review will focus on these current and possible therapeutic perspectives.

Trends in the Use of Adjuvant Chemotherapy for High-Grade Truncal and Extremity Soft Tissue Sarcomas.

BACKGROUND: In the randomized controlled trial (RCT) EORTC 62931, adjuvant chemotherapy failed to show improvement in relapse-free survival (RFS) or overall survival (OS) for patients with resected high-grade soft tissue sarcoma (STS). We evaluated whether the negative results of this 2012 RCT have influenced multidisciplinary treatment patterns for patients with high-grade STS undergoing resection at seven academic referral centers. METHODS: The U.S. Sarcoma Collaborative database was queried to identify patients who underwent curative-intent resection of primary high-grade truncal or extremity STS from 2000 to 2016. Patients with recurrent tumors, metastatic disease, and those receiving neoadjuvant chemotherapy were excluded. Patients were divided by treatment era into early (2000-2011, pre-European Organisation for Research and Treatment of Cancer [EORTC] trial) and late (2012-2016, post-EORTC trial) cohorts for analysis. Rates of adjuvant chemotherapy and clinicopathologic variables were compared between the two cohorts. Univariate and multivariate regression analyses were used to determine factors associated with OS and RFS. RESULTS: 949 patients who met inclusion criteria were identified, with 730 patients in the early cohort and 219 in the late cohort. Adjuvant chemotherapy rates were similar between the early and late cohorts (15.6% versus 14.6%; P = 0.73). Patients within the early and late cohorts demonstrated similar median OS (128 months versus median not reached, P = 0.84) and RFS (107 months versus median not reached, P = 0.94). Receipt of adjuvant chemotherapy was associated with larger tumor size (13.6 versus 8.9 cm, P < 0.001), younger age (53.3 versus 63.7 years, P < 0.001), and receipt of adjuvant radiation (P < 0.001). On multivariate regression analysis, risk factors associated with decreased OS were increasing American Society of Anesthesiologists class (P = 0.02), increasing tumor size (P < 0.001), and margin-positive resection (P = 0.01). Adjuvant chemotherapy was not associated with OS (P = 0.88). Risk factors associated with decreased RFS included increasing tumor size (P < 0.001) and margin-positive resection (P = 0.03); adjuvant chemotherapy was not associated with RFS (P = 0.23). CONCLUSIONS: Rates of adjuvant chemotherapy for resected high-grade truncal or extremity STS have not decreased over time within the U.S. Sarcoma Collaborative, despite RCT data suggesting a lack of efficacy. In this retrospective multi-institutional analysis, adjuvant chemotherapy was not associated with RFS or OS on multivariate analysis, consistent with the results from EORTC 62931. Rates of adjuvant chemotherapy for high-grade STS were low in both cohorts but may be influenced more by selection bias based on clinicopathologic variables such as tumor size, margin status, and patient age than by prospective, randomized data.

Analysis of textbook outcomes among patients undergoing resection of retroperitoneal sarcoma: A multi-institutional analysis of the US Sarcoma Collaborative.

BACKGROUND: The novel composite metric textbook outcome (TO) has increasingly been used as a quality indicator but has not been reported among patients undergoing surgical resection for retroperitoneal sarcoma (RPS) using multi-institutional collaborative data. METHODS: All patients who underwent resection for RPS between 2000 to 2016 from eight academic institutions were included. TO was defined as a patient with R0/R1 resection that discharged to home and was without transfusion, reoperation, grade ≥2 complications, hospital-stay >50th percentile, or 90-day readmission or mortality. Univariate and multivariable analyses were performed. RESULTS: Among 627 patients, 56.1% were female and the median age was 59 years. A minority of patients achieved a TO (34.9%). Factors associated with achieving a TO were tumor size <20 cm and low tumor grade, while ASA class ≥3, history of a prior cardiac event, resection of left colon/rectum, distal pancreatic resection, major venous resection and drain placement were associated with not achieving a TO (all P < .05). Achievement of a TO was associated with improved survival (median:12.7 vs 5.9 years, P < .01). CONCLUSIONS: Among patients undergoing resection for RPS, failure to achieve TO is common and associated with significantly worse survival. The use of TO may inform patient expectations and serve as a measure for patient-level hospital performance.

Neoadjuvant radiation improves margin-negative resection rates in extremity sarcoma but not survival.

BACKGROUND AND OBJECTIVES: Radiation improves limb salvage in extremity sarcomas. Timing of radiation therapy remains under investigation. We sought to evaluate the effects of neoadjuvant radiation (NAR) on surgery and survival of patients with extremity sarcomas. MATERIALS AND METHODS: A multi-institutional database was used to identify patients with extremity sarcomas undergoing surgical resection from 2000-2016. Patients were categorized by treatment strategy: surgery alone, adjuvant radiation (AR), or NAR. Survival, recurrence, limb salvage, and surgical margin status was analyzed. RESULTS: A total of 1483 patients were identified. Most patients receiving radiotherapy had high-grade tumors (82% NAR vs 81% AR vs 60% surgery; P < .001). The radiotherapy groups had more limb-sparing operations (98% AR vs 94% NAR vs 87% surgery; P < .001). NAR resulted in negative margin resections (90% NAR vs 79% surgery vs 75% AR; P < .0001). There were fewer local recurrences in the radiation groups (14% NAR vs 17% AR vs 27% surgery; P = .001). There was no difference in overall or recurrence-free survival between the three groups (OS, P = .132; RFS, P = .227). CONCLUSION: In this large study, radiotherapy improved limb salvage rates and decreased local recurrences. Receipt of NAR achieves more margin-negative resections however this did not improve local recurrence or survival rates over.

Perioperative chemotherapy is not associated with improved survival in high-grade truncal sarcoma.

BACKGROUND: The treatment benefit of perioperative chemotherapy (CTX) for truncal soft tissue sarcoma (STS) is not well established. This study evaluates the association of CTX with survival for patients with resected primary high-grade truncal STS. MATERIALS AND METHODS: Adult patients with high-grade truncal STS who had curative-intent resection from 2000 to 2016 at seven U.S. institutions were evaluated retrospectively. Patients were stratified by receipt of CTX. Kaplan-Meier curves with log-rank tests were used to compare overall survival (OS) and recurrence-free survival. Logistic regression models were used to evaluate characteristics associated with OS. RESULTS: Of patients with primary high-grade truncal STS, 235 underwent curative-intent resections. The most common histology was undifferentiated pleomorphic sarcoma and mean tumor size was 7.8 cm. Thirty percent of the patients received CTX (n = 70). Among patients receiving CTX, 34% (n = 24) had neoadjuvant CTX, 44% (n = 31) adjuvant CTX, and 21% (n = 15) had neoadjuvant and adjuvant CTX. Patients receiving CTX were more likely to receive radiation (51% versus 34%, P = 0.01), have deep tumors (86% versus 73%, P = 0.037) and solid organ invasion (14% versus 3%, P = 0.001). On univariate analysis, patients who received CTX had worse OS (P < 0.01) and a trend toward worse recurrence-free survival (P = 0.08). Margin status was the only variable associated with improved OS on multivariate analysis (odds ratio 4.36, 95% confidence interval 1.56, 12.13, P < 0.01). CONCLUSIONS: In this multi-institutional retrospective analysis of resected high-grade truncal STS, receipt of perioperative CTX was not associated with improved OS, which may be related to selection bias. Microscopically negative margin status was the only independent factor associated with OS.

Optimizing Perioperative Fluid Management in Complex Abdominal Wall Reconstruction to Prevent Postoperative Acute Kidney Injury.

BACKGROUND: Acute kidney injury (AKI) is a serious postoperative complication of abdominal wall reconstruction that can significantly impact outcomes of these patients. This study examines AKI following abdominal wall hernia repair to determine incidence and risk factors and outline potential mitigation strategies. METHODS: Using a single institution IRB-approved prospective database, patients undergoing complex abdominal wall reconstruction from 2013 to 2021 were identified. Patients with AKI were compared to controls and preoperative and intraoperative characteristics were evaluated. Multivariate analysis was utilized to identify factors associated with development of AKI. RESULTS: 297 patients were reviewed, 21.2 % (n = 63 patients) had AKI. Patients with AKI had a greater decrease in postoperative GFR to preoperative GFR (40.5% vs 18.3%, p <0.0001). Factors associated with AKI included ASA score >2 (odds ratio (OR) = 2.10, [1.50; 5.12], p = 0.02), HTN (OR = 2.05, [1.05; 4.0], p = 0.04), higher baseline Cr (OR = 5.98, [2.56; 13.98], p <0.0001), and diabetes (OR = 0.135, [0.0275; 0.666], p = 0.01). Operative time was longer in patients who developed AKI [average 400 min (range: 278-510 min) vs 310 min (range: 260-374 min), p = 0.04] and was an independent predictor of developing AKI (OR = 319.59, [137.25; 744.65], p <0.0001). DISCUSSION: Preoperative identification of patients with medical comorbidities undergoing elective complex abdominal wall reconstruction continues to be imperative to improve outcomes. This study demonstrates that perioperative management for high risk patients requires flexibility, including potential adjustments to enhanced recovery after surgery protocols in order to adequately address the risks for AKI.

Antibacterial and anti-inflammatory effects of Lactobacillus reuteri in its biofilm state contribute to its beneficial effects in a rat model of experimental necrotizing enterocolitis.

INTRODUCTION: Necrotizing enterocolitis (NEC) remains a significant surgical emergency in neonates. We have demonstrated the efficacy of Lactobacillus reuteri (Lr) in protecting against experimental NEC when administered as a biofilm by incubation with maltose loaded dextranomer microspheres. Lr possesses antimicrobial and anti-inflammatory properties. We developed mutant strains of Lr to examine the importance of its antimicrobial and anti-inflammatory properties in protecting the intestines from NEC. METHODS: Premature rat pups were exposed to hypoxia/hypothermia/hypertonic feeds to induce NEC. To examine the importance of antimicrobial reuterin and anti-inflammatory histamine, pups received either native or mutant forms of Lr, in either its planktonic or biofilm states, prior to induction of NEC. Intestinal histology was examined upon sacrifice. RESULTS: Compared to no treatment, administration of a single dose of Lr in its biofilm state significantly decreased the incidence of NEC (67% vs. 18%, p < 0.0001), whereas Lr in its planktonic state had no significant effect. Administration of reuterin-deficient or histamine-deficient forms of Lr, in either planktonic or biofilm states, resulted in significant loss of efficacy. CONCLUSION: Antimicrobial and anti-inflammatory effects of Lr contribute to its beneficial effects against NEC. This suggests that both infectious and inflammatory components contribute to the etiology of NEC.

A comparison of robotic-assisted splenectomy and laparoscopic splenectomy for children with hematologic disorders.

INTRODUCTION: Laparoscopic splenectomy (LS) is the standard of care for hematologic disorders requiring splenectomy. Less is known about the outcomes following robotic-assisted splenectomy (RS) for this indication. Our aim was to describe outcomes of RS to LS in pediatric patients with hematologic disorders in our institution. METHODS: A single institution retrospective review was performed of pediatric patients undergoing LS vs. RS from 2014 to 2019. Patient demographics, diagnosis, spleen size, hospital length of stay (LOS), operative time, post-operative opioid use, and hospital charges were evaluated. Standard univariate analyses were performed. RESULTS: Twenty-four patients were included in the study (14 LS, 10 RS). The mean spleen size at the time of surgery was larger in the RS group compared to LS (14.5 cm vs. 12.2 cm, p = 0.03). Operative time between the two cohorts was comparable (RS 140.5 vs LS 154.9 min). Median LOS for RS was shorter than LS (2.1 vs. 3.2 days, p = 0.02). Cumulative postoperative opioid analgesic requirements were not significantly different between the groups (17.4 mg vs. 30.5 mg). The median hospital charges, including the surgical procedure and hospital stay were higher in the RS group ($44,724 RS vs $30,255 LS, p = 0.01). CONCLUSION: Robotic splenectomy is a safe and feasible option for pediatric patients with hematologic disorders, and was associated with decreased LOS but higher charges compared to laparoscopic splenectomy. Further studies are required to delineate the optimal use and potential benefits of robot-assisted surgical techniques in children. LEVEL OF EVIDENCE: II.

Comparative analysis of robotic-assisted versus laparoscopic cholecystectomy in pediatric patients.

BACKGROUND: Despite increased utilization of robotic-assisted surgery in the pediatric population during the past decade, reports of comparative analysis between robotic surgery and laparoscopic surgery are lacking. Our aim was to evaluate outcomes between pediatric robotic-assisted cholecystectomy (RC) and laparoscopic cholecystectomy (LC). METHODS: A single institution retrospective analysis of 299 patients undergoing either RC or LC, between January 2015 and December 2018 was performed. Demographic data as well as clinical characteristics and related outcomes were abstracted and compared using univariate analysis. Related hospital costs were estimated using a charge to cost methodology. RESULTS: The median age of the cohort was 15.5 years (IQR 14.0-17.0); 76% females and 70% white, with 74% (n = 220) undergoing LC and 26% (n = 79) undergoing RC. The majority of RC were performed using single-site technique and RC proportion increased with time (10% in 2015 vs. 41% in 2018, p<0.001). The majority of RC were more commonly attributed to patients with nonacute indications for cholecystectomy compared to acute clinical indications (87% vs. 13%). Median operative time was 98 min vs. 79 min for RC and LC respectively (p<0.001). Median postoperative LOS was similar between groups (22 h). There were no significant differences in postoperative complication, in-hospital opioid utilization and 30-day readmissions. Average total hospital costs for RC were $15,519 compared to $11,197 for LC. CONCLUSIONS: Pediatric robotic-assisted cholecystectomy is feasible with similar outcomes compared to laparoscopic cholecystectomy. However, it is associated with longer operative times and higher costs. The single-site RC technique may provide a potential cosmetic benefit.

Resection Status Does Not Impact Recurrence in Well-Differentiated Liposarcoma of the Extremity.

BACKGROUND: Well-differentiated liposarcoma (WDLPS) is a low-grade soft tissue sarcoma with a propensity for local recurrence. The necessity of obtaining microscopically free surgical margins (R0) to minimize local recurrence is not clear. This study evaluates recurrence-free survival (RFS) of extremity WDLPS in relation to resection margin status. METHODS: A retrospective review of adult patients with primary extremity WDLPS at seven US institutions from 2000 to 2016 was performed. Patients with recurrent tumors or incomplete resection (R2) were excluded. Clinicopathologic factors were analyzed to assess impact on local RFS. RESULTS: 97 patients with primary extremity WDLPS were identified. The majority of patients had deep, lower extremity tumors. Mean tumor size was 18.2±8.9cm. Patients were treated with either radical (76.3%) or excisional (23.7%) resections; 64% had R0 and 36% had microscopically positive (R1) resection margins. Ten patients received radiation therapy with no difference in receipt of radiation between R0 vs R1 groups. Thirteen patients (13%) developed a local recurrence with no difference in RFS between R0 vs R1 resection. Five-year RFS was 59.5% for R0 vs 85.2% for R1. Only one patient died of disease after developing dedifferentiation and distant metastasis despite originally having an R0 resection. DISCUSSION: In this large multi-institutional study of surgical resection of extremity WDLPS, microscopically positive margins were not associated with an increased risk of recurrence. Positive microscopic margin resection for extremity WDLPS may yield similar rates of local control while avoiding a radical approach to obtain microscopically negative margins.

Key Areas for Development in Oncoplastic Breast Reconstruction.

Oncoplastic breast reconstruction addresses lumpectomy or partial mastectomy defects after breast conserving surgery. A large subset of breast cancer patients may be candidates for oncoplastic partial breast reconstruction, but are likely underserved in the United States due to multiple factors. In this article, the authors provide an understanding of current trends in the literature and an overview of key areas for improvement in the delivery of breast cancer surgical care. METHODS: A literature search of peer-reviewed articles relating to oncoplastic breast reconstruction was performed. In addition, current US laws relating to breast reconstruction, and communication and content from key surgical societies were reviewed. Key areas of improvement were identified after qualitative review of all sources. RESULTS: Thirty-four relevant resources were included. There is a large potential population need for oncoplastic breast reconstruction, but no current accurate estimate of patients undergoing this type of reconstruction. There are a multitude of definitions and algorithms attempting to define and organize oncoplastic breast surgery. Legislative initiatives could be improved to prevent coverage gaps. Coding and billing for oncoplastic surgery is not standardized, which complicates both clinical implementation and research efforts. Collaboration between national societies is needed. CONCLUSIONS: Oncoplastic partial breast reconstruction is an important part of the total package of care that can be offered to the breast cancer patient. Improvements in legislation, coding, and billing, and unification of national society communications and initiatives can lead to better surgical outcomes for the breast cancer patient.

A novel probiotic therapeutic in a murine model of Clostridioides difficile colitis.

For prophylactic therapy, mice received an oral antibiotic cocktail followed by clindamycin injection, followed by probiotic administration (planktonic vs. biofilm state), followed by C. difficile oral gavage. For treatment therapy, mice received antibiotics and C. difficile first, followed by probiotic administration. Clinical sickness scores (CSS) and intestinal histologic injury scores (HIS) were assigned.In the Prophylactic Therapy model, CSS: 67% of untreated mice exposed to C. difficile demonstrated CSS ≥ 6, which is consistent with C. difficile infection (p< .001 compared to unexposed mice). In mice treated with planktonic Lr, 55% had a CSS ≥ 6, but only 19% of mice treated with Lr in its biofilm state had CSS ≥ 6 (p< .001). Mice receiving Lr + DM-Maltose lost the least amount of weight compared to mice receiving saline (p = .004676) or to mice receiving Lr (p= .003185). HIS: 77% of untreated mice exposed to C. difficile had HIS scores ≥4, which is consistent with C. difficile infection. In mice treated with planktonic Lr, 62% had HIS ≥4, but only 19% of mice treated with Lr in its biofilm state had HIS ≥4. (p< .001). Additionally, mice treated with Lr in its biofilm state had better survival compared to untreated mice and to mice treated with planktonic Lr (p ≤ 0.05). Similar findings for weight loss, CSS, HIS and survival were obtained for Treatment Therapy.A single dose of Lactobacillus reuteri in its biofilm state reduces the severity and incidence of experimental C. difficile infection when administered as both prophylactic and treatment therapy.

Development of a Standardized Scoring System to Assess a Murine Model of Clostridium difficile Colitis.

Background: Clostridium difficile infection is the most common cause of antimicrobial-associated diarrhea. Our aim was to introduce a novel and efficient clinical sickness score (CSS), and to define a detailed histologic injury score (HIS) in a murine model of C. difficile colitis. Methods: Mice received an antibiotic cocktail (kanamycin, gentamicin, colistin, metronidazole, and vancomycin) for 96 h. After 48 h, mice received an intraperitoneal injection of clindamycin, followed by oral C. difficile (1.5 × 107 CFU). Signs of sickness were scored using a novel CSS (range 0-12) with scores ≥6 consistent with C. difficile colitis. Intestinal tissue was analyzed utilizing an adapted HIS (range 0-9) with scores ≥4 consistent with C. difficile colitis. Stool was analyzed for C. difficile, and survival evaluated. Results: No control mice showed signs of sickness, whereas 23% of mice receiving antibiotics alone and 65% of mice exposed to antibiotics and subsequently C. difficile demonstrated signs of sickness (p = 0.0134). No control mice had histologic injury, whereas 8% of mice receiving antibiotics alone and 75% of mice exposed to antibiotics followed by C. difficile had evidence of histologic injury (p = 0.0001). Mice exposed to C. difficile lost more weight, although not significant (p = 0.070). Mice that received C. difficile had decreased survival compared to control mice and mice receiving antibiotics only (p = 0.03). Conclusions: We have developed a novel clinical scoring system, and detailed histological grading system, that enables the objective evaluation of a murine C. difficile colitis model. This model allows the study of this disease in a host that demonstrates clinical and histologic signs comparable to human C. difficile infection. This will allow for improved study of therapeutics for this disease in the future.

Influence of Growth Factors on the Development of Necrotizing Enterocolitis.

Growth factors have important roles in gastrointestinal tract development, maintenance, and response to injury. Various experiments have been used to demonstrate growth factor influence in multiple disease processes. These studies demonstrated enhancement of mucosal proliferation, intestinal motility, immune modulation, and many other beneficial effects. Select growth factors, including epidermal growth factor and heparin-binding epidermal growth factor like growth factor, demonstrate some beneficial effects in experimental and clinical intestinal injury demonstrated in necrotizing enterocolitis. The roles of glucagon-like peptide 2, insulin-like growth factor 1, erythropoietin, growth hormone, and hepatocyte growth factor in necrotizing enterocolitis are summarized in this article.

Volume of Irrigation Does Not Affect Rate of Abscess in Perforated Appendicitis.

Background: Although previous studies have evaluated whether use of irrigation decreases postoperative intraabdominal abscess (PO-IAA) formation, these studies treated irrigation as a dichotomous variable and concluded that no irrigation resulted in a decreased incidence of PO-IAA formation. However, a recent study found decreased incidence with small aliquots to a total volume of 6 L. We hypothesized that higher volumes of irrigation would result in a lower incidence of PO-IAA. Materials and Methods: A postoperative template was developed as a quality improvement initiative and included descriptors for complex appendicitis and volume of irrigation. Data were prospectively collected from February 2016 to December 2018. Patients with complex appendicitis (fibropurulent exudate, extraluminal fecalith, well-formed abscess, visible hole in the appendix) were identified and analyzed by using standard statistical analysis. Volume of irrigation was categorized for analysis. Results: Two thousand three hundred six appendicitis patients were identified; 408 had complex appendicitis (17.7%). Three hundred eighty-four patients with complex appendicitis had documented irrigation volumes. The overall incidence of PO-IAA was 13.8%. Irrigation was commonly used (92.7%). The median amount of irrigation was 1000 mL (500 mL, 2500 mL), but it ranged from none to 9000 mL. There was no overall difference in the volume of irrigation used between those who developed a PO-IAA and those who did not (P = .34). No specific intraoperative finding was associated with the development of PO-IAA. Increasing volume of irrigation did not lower PO-IAA incidence (P = .24). Conclusions: The volume of irrigation did not appear to affect the rate of PO-IAA formation. The use of irrigation should be left to the discretion of the operating surgeon.