Rachel L. Berger

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.

Abdominal reoperation and mesh explantation following open ventral hernia repair with mesh

BACKGROUND This study sought to identify the incidence, indications, and predictors of abdominal reoperation and mesh explantation following open ventral hernia repair with mesh (OVHR). METHODS A retrospective cohort study of all patients at a single institution who underwent an OVHR from 2000 to 2010 was performed. Patients who required subsequent abdominal reoperation or mesh explantation were compared with those who did not. Reasons for reoperation were recorded. The 2 groups were compared using univariate and multivariate analysis (MVA). RESULTS A total of 407 patients were followed for a median (range) of 57 (1 to 143) months. Subsequent abdominal reoperation was required in 69 (17%) patients. The most common reasons for reoperation were recurrence and surgical site infection. Only the number of prior abdominal surgeries was associated with abdominal reoperation on MVA. Twenty-eight patients (6.9%) underwent subsequent mesh explantation. Only the Ventral Hernia Working Group grade was associated with mesh explantation on MVA. CONCLUSIONS Abdominal reoperation and mesh explantation following OVHR are common. Overwhelmingly, surgical complications are themost common causes for reoperation and mesh explantation.

Outcomes with Porcine Acellular Dermal Matrix versus Synthetic Mesh and Suture in Complicated Open Ventral Hernia Repair

BACKGROUND Mesh reinforcement as part of open ventral hernia repair (OVHR) has become the standard of care. However, there is no consensus on the ideal type of mesh to use. In many clinical situations, surgeons are reluctant to use synthetic mesh. Options in these complicated OVHRs include suture repair or the use of biologic mesh such as porcine acellular dermal matrix (PADM). There has been a paucity of controlled studies reporting long-term outcomes with biologic meshes. We hypothesized that compared with synthetic mesh in OVHR, PADM is associated with fewer surgical site infections (SSI) but more seromas and recurrences. Additionally, compared with suture repair, we hypothesized that PADM is associated with fewer recurrences but more SSIs and seromas. METHODS A retrospective study was performed of all complicated OVHRs performed at a single institution from 2000-2011. All data were captured from the electronic medical records of the service network. Data were compared in two ways. First, patients who had OVHR with PADM were case-matched with patients having synthetic mesh repairs on the basis of incision class, Ventral Hernia Working Group (VHWG) grade, hernia size, American Society of Anesthesiologists (ASA) class, and emergency status. The PADM cases were also matched with suture repairs on the basis of incision class, hernia grade, duration of the operation, ASA class, and emergency status. Second, we developed a propensity score-adjusted multi-variable logistic regression model utilizing internal resampling to identify predictors of primary outcomes of the overall cohort. The U.S. Centers for Disease Control and Prevention (CDC) definition of SSI was utilized; seromas and recurrences were defined and tracked similarly for all patients. Data were analyzed using the McNemar, X(2), paired two-tailed Student t, or Mann-Whitney U test as appropriate. RESULTS A total of 449 complicated OVHR cases were reviewed for a median follow up of 61 mos (range 1-143 mos): 94 patients had PADM repairs, whereas 154 patients underwent synthetic mesh repairs, and 201 had suture repairs. The 40 PADM repairs were matched to synthetic repairs and 59 were matched to suture repairs. The PADM repairs that could not be well matched (n=54 unmatched for synthetic repairs, 35 unmatched for suture repairs) were characterized generally by larger hernias, VHWG grades of 3 or 4, and incision class 3 or 4 with longer operative durations and more ASA class 4 cases. The patients were well matched. Comparing PADM with synthetic mesh, there was no difference in SSI (20% vs. 35%; p=0.29), seromas (32.5% vs. 15%; p=0.17), mesh explantations (5% vs. 15%, p=0.28), readmissions within 90 d (37.5% vs. 45%; p=1.00), or recurrence (8.5% vs. 22.5%; p=0.15). Compared with suture repair, patients with PADM had fewer recurrences (11.9% vs. 33.9%; p<0.01) and more seromas (32.2% vs. 10.2%; p=0.02), but a similar number of SSIs (23.7% vs. 39.0%; p=0.19) and 90-d readmissions (35.6% vs. 39.0%; p=0.88). Propensity score-adjusted multi-variable logistic regression of the entire cohort corroborated the results of the case-matched patients. CONCLUSIONS The PADM repair of complicated OVHR resulted in fewer recurrences, more seromas, and no difference in SSI compared with suture repair. Although no reduction in SSI was identified with the use of PADM rather than synthetic mesh or suture for OVHR, the meaning of this finding is unclear, as this case-controlled study was underpowered and limited by selection bias. According to our data, 280 patients would have been needed to identify a clinically significant difference in the primary outcome of SSI as well as secondary outcomes of mesh explantation and recurrence (α=0.05; β=0.20). A randomized trial is warranted to compare PADM with synthetic mesh in complicated OVHR.

Circular closure is associated with the lowest rate of surgical site infection following stoma reversal: a systematic review and multiple treatment meta-analysis.

Stoma reversal is frequently complicated by surgical site infection (SSI). To reduce SSI, several techniques for skin closure have been studied, with no agreement on which is best. The aim of this study was to identify the skin closure technique associated with the lowest rate of SSI following stoma reversal.

Outcomes of acute versus elective primary ventral hernia repair.

BACKGROUND The morbidity and mortality associated with acute primary ventral hernia repair have not been well described. We examined the rate of surgical site infection (SSI), hernia recurrence, and mortality in acute versus elective primary ventral hernia repair and identified predictors of morbidity and mortality after primary ventral hernia repair. METHODS A retrospective study on all patients undergoing open primary ventral hernia repair at a single institution (2000–2010) was performed. Primary outcomes were mortality at any time, SSI, and recurrence. Survival analysis for the entire, unmatched sample was conducted. We performed a risk-adjusted analysis of outcomes using two methods as follows: (1) case matching and (2) propensity score–adjusted regression model. RESULTS We identified 497 patients; 57 (11%) underwent acute primary ventral hernia repair. For the entire cohort, survival was worse for patients undergoing acute repair (log rank, 0.03). Following case matching on age, body mass index, American Society of Anesthesiologists score, and hernia size, there was no difference in mortality, SSI, or recurrence. After propensity score adjustment, acute surgery was not a predictor for mortality or SSI; however, incarcerated hernias predicted recurrence. CONCLUSION After risk adjustment, acute primary ventral hernia repair was not associated with higher mortality, infection, or recurrence compared with elective repair. LEVEL OF EVIDENCE Therapeutic study, level IV.

Review of stoma site and midline incisional hernias after stoma reversal

BACKGROUND The incidence of incisional hernias after stoma reversal is not well reported. The aim of this study was to systematically review the literature reporting data on incisional hernias after stoma reversal. We evaluated both the incidence of stoma site and midline incisional hernias. METHODS A systematic review identified studies published between January 1, 1980, and December 31, 2012, reporting the incidence of incisional hernia after stoma reversal at either the stoma site or at the midline incision (in cases requiring laparotomy). Pediatric studies were excluded. Assessment of risk of bias, detection method, and essential study-specific characteristics (follow-up duration, stoma type, age, body mass index, and so forth) was done. RESULTS Sixteen studies were included in the analysis; 1613 patients had 1613 stomas formed. Fifteen studies assessed stoma site hernias and five studies assessed midline incisional hernias. The median (range) incidence of stoma site incisional hernias was 8.3% (range 0%-33.9%) and for midline incisional hernias was 44.1% (range 8.7%-58.1%). When evaluating only studies with a low risk of bias, the incidence for stoma site incisional hernias is closer to one in three and for midline incisional hernias is closer to one in two. CONCLUSION Stoma site and midline incisional hernias are significant clinical complications of stoma reversals. The quality of studies available is poor and heterogeneous. Future prospective randomized controlled trials or observational studies with standardized follow-up and outcome definitions/measurements are needed.