Mike K. Liang

Development and Validation of a Risk-Stratification Score for Surgical Site Occurrence and Surgical Site Infection after Open Ventral Hernia Repair

BACKGROUND Current risk-assessment tools for surgical site occurrence (SSO) and surgical site infection (SSI) are based on expert opinion or are not specific to open ventral hernia repairs. We aimed to develop a risk-assessment tool for SSO and SSI and compare its performance against existing risk-assessment tools in patients with open ventral hernia repair. STUDY DESIGN A retrospective study of patients undergoing open ventral hernia repair (n = 888) was conducted at a single institution from 2000 through 2010. Rates of SSO and SSI were determined by chart review. Stepwise regression models were built to identify predictors of SSO and SSI and internally validated using bootstrapping. Odds ratios were converted to a point system and summed to create the Ventral Hernia Risk Score (VHRS) for SSO and SSI, respectively. Area under the receiver operating characteristic curve was used to compare the accuracy of the VHRS models against the National Nosocomial Infection Surveillance Risk Index, Ventral Hernia Working Group (VHWG) grade, and VHWG score. RESULTS The rates of SSO and SSI were 33% and 22%, respectively. Factors associated with SSO included mesh implant, concomitant hernia repair, dissection of skin flaps, and wound class 4. Predictors of SSI included concomitant repair, dissection of skin flaps, American Society of Anesthesiologists class ≥ 3, wound class 4, and body mass index ≥ 40. The accuracy of the VHRS in predicting SSO and SSI exceeded National Nosocomial Infection Surveillance and VHWG grade, but was not better than VHWG score. CONCLUSIONS The VHRS identified patients at increased risk for SSO/SSI more accurately than the National Nosocomial Infection Surveillance scores and VHWG grade, and can be used to guide clinical decisions and patient counseling.

Outcomes of laparoscopic vs open repair of primary ventral hernias

IMPORTANCE More primary ventral hernias (PVHs) are being repaired using the technique of laparoscopic ventral hernia repair (LVHR). Few studies exist comparing the outcomes of LVHR with the outcomes of open ventral hernia repair (OVHR) for PVHs. We hypothesize that LVHR of PVHs is associated with fewer surgical site infections (SSIs) but more hernia recurrences and more clinical cases of bulging (bulging not associated with recurrence or seroma). OBJECTIVE To compare the outcomes of patients who underwent LVHR with the outcomes of patients who underwent OVHR. DESIGN Retrospective study of 532 consecutive patients who underwent an elective PVH repair at a single institution from 2000 to 2010. The outcomes of the 2 procedures were compared using 2 statistical methods. Multivariable logistic regression was used to evaluate the association between outcomes and several independent factors, adjusting for treatment propensity, and the outcomes in the 2 groups of patients were compared using paired univariate analysis. SETTING Michael E. DeBakey VA Medical Center in Houston, Texas. PARTICIPANTS Seventy-nine patients who underwent LVHR and 79 patients who underwent OVHR. MAIN OUTCOMES AND MEASURES The primary outcomes of interest were SSI, hernia recurrence, and bulging. The 2 groups of patients were matched by hernia size, American Society of Anesthesiologists class, age, and body mass index. RESULTS There were 91 patients who underwent an LVHR and 167 patients who underwent an OVHR with mesh, with a median follow-up period of 56 months (range, 1-156 months). Seventy-nine patients with an LVHR were matched to 79 patients with an OVHR. No significant differences in demographic data or confounding factors were detected between the 2 groups. Compared with OVHR, LVHR was significantly associated with fewer SSIs (7.6% vs 34.1%; P < .01) but more clinical cases of bulging (21.5% vs 1.3%; P < .01) and port-site hernia (2.5% vs 0.0%). No differences in recurrence at the site of the hernia repair were observed (11.4% vs 11.4%; P = .99). Propensity score-matched multivariate analysis corroborated that LVHR is associated with more clinical cases of bulging but fewer SSIs. CONCLUSIONS AND RELEVANCE Compared with OVHR of PVHs, LVHR of PVHs is associated with fewer SSIs but more clinical cases of bulging and with the risk of developing a port-site hernia. Further study is needed to clarify the role of LVHR of PVHs and to mitigate the risk of port-site hernia and bulging.

Outcomes and Predictors of Incisional Surgical Site Infection in Stoma Reversal

IMPORTANCE Surgical site infection following stoma reversal (SR) poses a substantial burden to the patient and health care system. Its overall incidence is likely underreported and poorly characterized. Improving our understanding of surgical site infection following stoma reversal may help us identify methods to decrease this complication. OBJECTIVE To evaluate the incidence of surgical site infection (SSI) and identify predictors of SSI following SR. DESIGN A review of computerized hospital records on SR performed from January 1, 2005, until February 27, 2011. SETTING An integrated medical system at the Michael E. DeBakey Veterans Affairs Medical Center. PARTICIPANTS AND INTERVENTION All adults undergoing SR during the study period. MAIN OUTCOME MEASURES Rates of SSI and characteristics of patients with and without SSI were compared. A logistic regression model was developed to identify predictors of SSI. RESULTS One hundred twenty-eight patients underwent SR; 46 patients (36.0%) had an SSI. In comparison with no SSI, the infection was associated with seromas (17.4% vs 2.4%, P = .004), fascial dehiscence (15.2% vs 2.4%, P = .01), intensive care unit admission (34.8% vs 17.1%, P = .03), increased hospital length of stay (20 vs 9 days, P = .02), readmission (32.6% vs 13.4%, P = .01), delayed wound healing (91 vs 66 days, P = .02), and reoperation (32.6% vs 13.4%, P = .01). On multivariate analysis, history of fascial dehiscence (odds ratio, 16.9; 95% CI, 1.94-387), colostomy (5.07; 2.12-13.0), thicker subcutaneous fat (2.02; 1.33-3.21), and black race (0.35; 0.13-0.86) were associated with incisional SSI. There was no significant difference in patient satisfaction or functional status in late follow-up (1-73 months). CONCLUSIONS AND RELEVANCE Surgical site infection is common following SR and is associated with significant morbidity. Four factors are strongly associated with increased risk of SSI in SR: history of fascial dehiscence, thicker subcutaneous fat, colostomy, and white race. Patients with none of these risk factors had a 0% SSI risk; patients with all 4 risk factors had a 100% risk of SSI.

Mesh shift following laparoscopic ventral hernia repair

INTRODUCTION Traditionally, laparoscopic ventral hernia repair (LVHR) is performed by placing the trocars on one side of the abdomen. Tacking the mesh on the operative side can be challenging. We hypothesized that mesh shift may occur as a result of this approach. We define mesh shift as any mesh off-center, where the center is the hernia defect. Our objectives were to evaluate whether mesh shift occurs after LVHR, and to develop a grading system to describe this phenomenon. METHODS We conducted a retrospective review of patients who underwent LVHR from 2000 to 2010. We examined patient demographics, comorbidities, radiographic data, surgical data, and outcomes. Using analysis of variance, we analyzed continuous data; we used Chi squared to analyze categorical data. Of the 201 patients, we reviewed 78 postoperative computed tomography (CT) scans. Two surgeons measured mesh overlap of the fascia bilaterally at the level of the hernia defect. We compared a ratio of the two sides of overlap (least overlap/greatest overlap) and classified patients into four grades: grade I, no mesh shift (ratio of 0.5-1.00); grade II, mild mesh shift (ratio of 0.20-0.49); grade III, moderate mesh shift (>0-0.19); and grade IV, major mesh shift with recurrence (<0). Any recurrence was classified as a grade IV shift. RESULTS A total of 48% of patients had mesh shift (grade II = 23%; grade III = 10%; and grade IV = 17%). In 92% of the patients with mesh shift, the mesh migrated away from the port placement site, resulting in decreased mesh/fascial overlap. Patients in the four groups had similar demographics, comorbid conditions, hernia characteristics, operative technique, and outcomes (excluding recurrences, which were all grade IV by definition). Whereas differences in time to follow-up CT scan in the different grades were not statistically significant, there was a trend toward increasing shift with time (mean: grade I, 20 mo; grade II, 38 mo; grade III, 50 mo; and grade IV, 26 mo; P = 0.07). A total of 26 patients (33%) had multiple postoperative CT scans. With time, it appears that mesh tended to shift with time (grade I, 68%-46%; grade II, 12%-19%; grade III, 12%-8%, and grade 4, 8%-23%). CONCLUSIONS Mesh can shift from the ideal central placement after LVHR. Mesh tends to shift away from the operative side and recurrences tend to occur on the operative side. Mesh shift may be a precursor to hernia recurrence. Recurrence may be a two-step process, beginning first with intra-operative mesh shift followed by additional factors (such mesh contraction) that may accentuate the shift and lead to recurrence. Potential solutions include increasing mesh overlap (≥ 6 cm), performing transcutaneous closure of central defect, securing trans-fascial sutures before tacking, placing operative side tacks first, and consider placing contralateral ports to secure the mesh.

Readmission following open ventral hernia repair: incidence, indications, and predictors

BACKGROUND The aim of this study was to evaluate the incidence, indications, and predictive factors of hospital readmission after open ventral hernia repair. METHODS A retrospective review of all open ventral hernia repairs at a single institution from 2000 to 2010 was performed to assess readmissions between 1 to 30, 1 to 90, and 91 to 365 days. Multivariate analysis was performed to identify independent predictors of 30-day readmission. RESULTS Of the 888 patients, 75 (8%) were readmitted between 1 and 30 days, 97 (11%) between 1 and 90 days, and 78 (9%) between 91 and 365 days. Unplanned readmissions related to the surgery constituted the majority of 1-day to 30-day and 1-day to 90-day readmissions (82% and 74%, respectively) but not between 91 and 365 days (32%). Prior superficial or deep surgical-site infection (odds ratio, 2.39; 95% confidence interval, 1.32 to 4.32) and duration of surgery (odds ratio, 1.35; 95% confidence interval, 1.05 to 1.73) were associated with 30-day readmission. CONCLUSIONS Efforts to reduce readmissions should be directed at modifiable risk factors for surgical-site infection and other surgical complications, particularly among those with prior skin infections and longer durations of surgery.

Laparoscopic transcutaneous closure of central defects in laparoscopic incisional hernia repair

Purpose: The aim of this technical report is to investigate the safety, efficacy, and outcome of transcutaneous closure of central defects (TCCD) for laparoscopic incisional hernia repair (LIHR). Methods: Twenty-two patients with incisional hernias underwent a LIHR-TCCD repair. After clearance of the abdominal wall from adhesions, laparoscopic central closures were performed transcutaneously with 0-polypropelene sutures placed every 1 cm of the defect starting at the cranial-most edge of the hernia and ending at the caudal-most edge of the hernia. A standard LIHR was performed with coated polyester mesh placed with at least 6 cm of overlap with mesh on all borders. Transfascial sutures with 0-polypropelene sutures were placed every 4 cm circumferentially, and titanium tacks were used to secure the mesh to the peritoneum every 1 cm. Results: The mean age was 52 years and the mean body mass index was 35 kg/m2. The mean hernia defect was 4.7 cm×7.2 cm with a mean area of 37 cm2. There were no mortalities and no major perioperative morbidities. Minor complications included 2 (9%) cases of pneumonia/pneumonitis. There were no clinically significant seromas, no radiographic or clinical eventrations, and no hernia recurrences with a mean follow-up of 21 months. Conclusions: LIHR-TCCD is safe and technically feasible in incisional hernias of width <10 cm. By closing the central defect, seromas and eventrations can be reduced.

Predictors of relaparotomy after nontrauma emergency general surgery with initial fascial closure.

BACKGROUND Relaparotomy after emergency surgery for nontrauma intraabdominal catastrophes (NTIAC) is morbid. Our objective was to identify patients who likely will need on-demand relaparotomy after surgery for NTIAC. METHODS A retrospective chart review of patients from 1998 to 2008 identified cases of NTIAC surgery with fascial closure. Demographics, comorbidities, intraoperative findings, morbidity, and mortality were analyzed. Relaparotomy was defined as any return to the operating room with surgical re-entry of the abdominal cavity. RESULTS A total of 129 patients underwent NTIAC surgery with fascial closure. Twenty-nine patients (22%) required relaparotomy and 100 patients (78%) did not. Multivariate analysis identified the following predictors of relaparotomy: peripheral vascular disease (P = .04), alcohol abuse (P = .02), body mass index of 29 kg/m(2) or greater (P = .04), the finding of any ischemic bowel (P = .02), and operating room latency of 60 hours or longer (P = .01). Patients with 2 or more of these predictors had a 55% risk of relaparotomy whereas patients with fewer than 2 of these predictors had a 9% risk (P < .001). CONCLUSIONS Patients whose fascia is closed during NTIAC surgery do worse when they require relaparotomy. We have identified preoperative and intraoperative predictors that may help identify patients at high risk of on-demand relaparotomy.

True duplication of the vas deferens: a case report and review of literature

BackgroundDuplication of the vas deferens is the identification of a second vas deferens within the spermatic cord; it is a rarely reported congenital anomaly. Duplicate vas deferens should not be confused with double vas deferens that describes ipsilateral renal agenesis with a blind ureter ending in the ejaculatory system.Data sourcesWe present a case of duplicated vas deferens, and a PubMed Medline (National Library of Medicine) search was performed using the terms “[duplicated OR double]” and “vas deferens”. Nineteen papers for a total of twenty-two cases (including ours) were identified.ConclusionsDuplication of vas deferens is a rare finding; it is likely under-reported and underrecognized. Failure to recognize this variation can result in injury to the vas deferens or an ineffective vasectomy. Following identification of a suspected duplicated vas deferens, the structure should be tracked from the internal ring down to the epididymis and intra-operative Doppler should be performed. Post-operatively, renal and bladder imaging can be considered though there have been no reported cases of non-testicular genito-urinary anomalies associated with duplicated vas deferens.

Differentiation of ileostomy from colostomy procedures: Assessing the accuracy of current procedural terminology codes and the utility of natural language processing

BACKGROUND Large databases provide a wealth of information for researchers, but identifying patient cohorts often relies on the use of current procedural terminology (CPT) codes. In particular, studies of stoma surgery have been limited by the accuracy of CPT codes in identifying and differentiating ileostomy procedures from colostomy procedures. It is important to make this distinction because the prevalence of complications associated with stoma formation and reversal differ dramatically between types of stoma. Natural language processing (NLP) is a process that allows text-based searching. The Automated Retrieval Console is an NLP-based software that allows investigators to design and perform NLP-assisted document classification. In this study, we evaluated the role of CPT codes and NLP in differentiating ileostomy from colostomy procedures. METHODS Using CPT codes, we conducted a retrospective study that identified all patients undergoing a stoma-related procedure at a single institution between January 2005 and December 2011. All operative reports during this time were reviewed manually to abstract the following variables: formation or reversal and ileostomy or colostomy. Sensitivity and specificity for validation of the CPT codes against the mastery surgery schedule were calculated. Operative reports were evaluated by use of NLP to differentiate ileostomy- from colostomy-related procedures. Sensitivity and specificity for identifying patients with ileostomy or colostomy procedures were calculated for CPT codes and NLP for the entire cohort. RESULTS CPT codes performed well in identifying stoma procedures (sensitivity 87.4%, specificity 97.5%). A total of 664 stoma procedures were identified by CPT codes between 2005 and 2011. The CPT codes were adequate in identifying stoma formation (sensitivity 97.7%, specificity 72.4%) and stoma reversal (sensitivity 74.1%, specificity 98.7%), but they were inadequate in identifying ileostomy (sensitivity 35.0%, specificity 88.1%) and colostomy (75.2% and 80.9%). NLP performed with greater sensitivity, specificity, and accuracy than CPT codes in identifying stoma procedures and stoma types. Major differences where NLP outperformed CPT included identifying ileostomy (specificity 95.8%, sensitivity 88.3%, and accuracy 91.5%) and colostomy (97.6%, 90.5%, and 92.8%, respectively). CONCLUSION CPT codes can identify effectively patients who have had stoma procedures and are adequate in distinguishing between formation and reversal; however, CPT codes cannot differentiate ileostomy from colostomy. NLP can be used to differentiate between ileostomy- and colostomy-related procedures. The role of NLP in conjunction with electronic medical records in data retrieval warrants further investigation.

Protocol for a randomized trial of the effect of timing of cholecystectomy during initial admission for predicted mild gallstone pancreatitis at a safety-net hospital

Background There is evidence-based consensus for laparoscopic cholecystectomy during index admission for predicted mild gallstone pancreatitis, defined by the absence of organ failure and of local or systemic complications. However, the optimal timing for surgery within that admission is controversial. Early cholecystectomy may shorten hospital length of stay (LOS) and increase patient satisfaction. Alternatively, it may increase operative difficulty and complications resulting in readmissions. Methods This trial is a single-center randomized trial of patients with predicted mild gallstone pancreatitis comparing laparoscopic cholecystectomy with intraoperative cholangiogram (IOC) at index admission within 24 hours of presentation versus after clinical resolution on clinical and patient-reported outcomes (PROs). The primary endpoint is 30-day LOS (hours) after initial presentation, which includes the index admission and readmissions. Secondary outcomes are conversion to open, complications, time from admission to cholecystectomy, initial hospital LOS, number of procedures within 30 days, 30-day readmissions, and PROs (change in Gastrointestinal Quality-of-Life Index). Discussion The primary goal of this research is to obtain the least biased estimate of effect of timing of cholecystectomy for mild gallstone pancreatitis on clinical and PROs; the results of this trial will be used to inform patient care locally as well as to design future multicenter effectiveness and implementation trials. This trial will provide data regarding PROs including health-related quality of life that can be used in cost-utility and cost-effectiveness analyses. Trial registration number NCT02806297, ClinicalTrials.gov.