Identification of primary ventral hernia (A), excision of hernia sac (B), excision of preperitoneal fat (C), and complete exposure of the hernia fascial edges (D).
Liang MK, Berger RL, Li LT, Davila JA, Hicks SC, Kao LS. Outcomes of Laparoscopic vs Open Repair of Primary Ventral Hernias. JAMA Surg. 2013;148(11):1043-1048. doi:10.1001/jamasurg.2013.3587
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).
To compare the outcomes of patients who underwent LVHR with the outcomes of patients who underwent OVHR.
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.
Michael E. DeBakey VA Medical Center in Houston, Texas.
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.
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.
Ventral hernia repairs are one of the most common procedures performed in the United States with more than 365 000 repairs performed annually.1 The vast majority of these hernias are primary ventral hernias (PVHs).2 The European Hernia Society classified hernias as either primary hernias (such as umbilical or epigastric hernias) or incisional hernias.
Ventral hernias can be repaired using a laparoscopic or an open technique. Laparoscopic ventral hernia repair (LVHR) has exploded in popularity, and there is a great deal of interest in using this technique for PVHs. With the paucity of adhesions and the simplicity of repair, the laparoscopic approach for PVH is the easiest way for many general surgeons to learn LVHR.3 For experienced laparoscopic surgeons, LVHR of PVHs is popular when evaluating large defects or morbidly obese patients.
There is a paucity of evidence to substantiate the preference of LVHR over OVHR for PVHs. Numerous studies have compared the outcomes of patients who underwent LVHR with the outcomes of patients who underwent OVHR; however, most of these studies have focused on incisional hernias or a mixed population of ventral hernia repairs.4Quiz Ref IDUsing data from a single institution, we conducted a retrospective cohort study to examine outcomes associated with LVHR vs those associated with OVHR for PVHs. We hypothesized that LVHR is associated with fewer surgical site infections (SSIs) but more hernia recurrences and more clinical cases of bulging.
Quiz Ref IDA retrospective risk-adjusted study of all repairs of PVHs with mesh at a single institution from 2000 to 2010 was performed.
The primary outcomes of interest were SSI, hernia recurrence, and bulging. An SSI was classified according to the Centers for Disease Control and Prevention definition.5 Hernia recurrence was determined based on clinical examination, radiographic evaluation, or at the time of reoperation. Hernia recurrence was further classified as central recurrence (recurrence at the site of the hernia repair) or port-site hernia (hernia from a laparoscopic port distant from the hernia repair site). Bulging was defined as any patient complaint or clinician assessment of bulging not related to hernia recurrence or seroma.6 Secondary outcomes of interest included seroma formation, surgical site occurrence, hospital length of stay, hospital readmissions, and reoperation rates. Seroma was determined based on the results of a clinical examination demonstrating a symptomatic fluid collection. Surgical site occurrence was a pooled result of all SSIs, seromas, hematomas, wound dehiscences, and enterocutaneous fistulas.7
Standardized template forms related to anesthesia, surgical history, and a physical examination are routinely used to accurately capture data. Data on patient demographics (age, sex, and ethnicity), American Society of Anesthesiologists class, body mass index, comorbidities (prostate disease, abdominal aortic aneurysm, chronic obstructive pulmonary disease, coronary artery disease, immunosuppression, diabetes mellitus, and alcohol use disorder), steroid use, smoking, type of hernia, hernia area (with size defined by the European Hernia Society), Ventral Hernia Working Group grade,7 and outcome were collected from the patients’ medical records. Immunosuppression was defined as having used steroids or having received chemotherapy within 30 days of surgery. Alcohol use disorder was defined as having more than 2 drinks per day. Data on the diameters of the hernias were captured by operative reports, and if these reports were not available, radiographic data were used. Hernia size was defined by the European Hernia Society classification system.2 Hernia area was calculated as a formula for an ellipse.
Laparoscopic ventral hernia repair was performed in the standard fashion as taught by the American College of Surgeons. Two or 3 ports were placed along the lateral aspect of the abdomen. Once the hernia was identified, a piece of coated mesh was placed as an underlay with at least 3 cm of overlap from the margins of the hernia defect. During the study period, hernia sacs and hernia contents were not routinely excised. Four transfascial sutures were used to secure the mesh in position, and titanium tacks were placed every centimeter on the perimeter of the mesh. The mesh was either coated polypropylene or polytetrafluoroethylene.
For an OVHR with mesh, a polypropylene mesh was placed in the preperitoneal space using the medium- or large-sized Prolene Hernia System (Ethicon). The onlay portion of the mesh was excised, and closure of the fascial defect was at the discretion of the attending surgeon. If the fascia was not closed, the fascia was secured to the central ring of the mesh.
All surgeons were proficient in LVHR and OVHR. Proficiency was determined by prior expertise based on case volume or following 10 observed cases with an experienced surgeon.
Patient groups were compared 2 different ways. First, patients who received an LVHR were matched to patients who received an OVHR, based on hernia size by European Hernia Society classification, American Society of Anesthesiologists class, age, and body mass index. Categorical data were matched by direct matching ±1, and continuous data were matched by the nearest neighbor. Five variables were compared using a paired 2-tailed t test or Mann-Whitney U test. Thirty-one variables were compared using the McNemar test or the χ2 test.
Second, outcomes were examined for the entire cohort (all LVHRs and all OVHRs with mesh) using multivariable logistic analysis adjusted for propensity to receive treatment. A propensity score was developed based on surgeon, hernia size, American Society of Anesthesiologists class, age, year of surgery, and body mass index. These variables were selected for the propensity score based on clinical expertise. All preoperative and intraoperative variables were included in the model and completely reduced to only significant variables using a bootstrapping technique (internal resampling). For recurrence, the duration of follow-up was also included as an independent variable. Models were created for the dependent variables of SSI, hernia recurrence (pooled data on central recurrences and port-site hernias), seroma, and bulging. Diagnostics of the multivariate regression model were assessed, and validation was performed using K-fold cross-validation. All statistical analyses were performed using the statistical software R (Vienna University of Economics and Business).
There were a total of 532 consecutive patients who underwent an elective PVH repair during the study period (Figure 1). Of these patients, 91 underwent an LVHR and 165 underwent an OVHR with mesh; they were followed up for a median of 56 months (range, 1-156 months).
Of the 91 patients who underwent an LVHR, 79 were matched to 79 patients who underwent an OVHR. Patients were well matched with no differences in demographic or hernia data (Table 1). Matched patients tended to be obese with large hernia defects. Quiz Ref IDPatients with an LVHR were less likely to develop an SSI but more likely to develop a postoperative ileus, to have bulging, and to have a prolonged length of hospital stay (Table 2). Although there were no differences in central recurrence, the rate of port-site recurrence was 2.5% for patients with an LVHR.
Quiz Ref IDOn multivariate analysis, surgical technique (laparoscopic vs open) was associated with an SSI and bulging, whereas only the size of the hernia defect was related to recurrence (Table 3).
Compared with OVHR of PVHs, LVHR of PVHs is associated with fewer SSIs but more clinical cases of bulging. There is no difference in recurrence rates, but LVHRs are subject to port-site recurrences.
There have been 6 prior studies evaluating the outcomes of LVHRs vs OVHRs: 5 retrospective studies8- 12 with no risk adjustment and 1 prospective randomized trial13 with only 40 patients. Including our results, overall, there have been 517 LVHRs and 475 OVHRs compared. For LVHRs, the pooled SSI rate is 3% (range, 0%-13%), and the pooled recurrence rate is 4% (range, 0%-14%). For OVHRs, the pooled SSI rate is 14% (range, 6%-30%), and the pooled recurrence rate is 5% (range, 0%-20%). To our knowledge, the present study is one of the first risk-adjusted controlled studies comparing the outcomes of LVHRs with the outcomes of OVHRs with regard to PVHs, and it is the only study reporting bulging as an outcome.
Similar to studies evaluating ventral and incisional hernia repairs, an LVHR portends identical benefits. In a meta-analysis of all prospective randomized controlled trials of LVHRs vs OVHRs, Sauerland et al14 identified similar results: an LVHR is associated with a lower rate of SSIs and no difference in hernia recurrence.
To our knowledge, the present study is the first to evaluate bulging after the repair of a PVH. Bulging of mesh or tissue is a common concern with laparoscopic repair and is becoming more widely recognized as a primary outcome.6,15,16 With open repair, the hernia contents of preperitoneal fat or hernia sac are typically reduced; however, with laparoscopic repair, it is not routinely taught to surgeons to excise the hernia sac or preperitoneal fat. Following repair, while the hernia is no longer at risk for incarceration, patients will often complain of continued sensation of bulging or persistent “hernia” (Figure 2).
Quiz Ref IDAnother concern of laparoscopic repair of PVHs is the risk of port-site hernias. It is well recognized that the risk of hernia formation with 10- to 12-mm ports ranges from 1% to 5% and that the risk with 5-mm ports ranges from 0.1% to 1%.17 In our study, we noted that 2.5% of patients had port-site hernia recurrences, typically of the 12-mm lateral port site (Figure 3).
One option to obviate these potential complications is to excise the hernia sac and preperitoneal fat prior to mesh placement (Figure 4). In addition, the avoidance of 12-mm ports or the placement of a 12-mm port through the hernia in order to introduce the mesh are other options. Finally, closure of the central defect may play a further role in preventing bulging and seroma formation.18,19
Our study has a number of limitations. This is a retrospective study with inherent selection biases, treatment biases, and classification errors. We attempted to mitigate selection and treatment biases by controlling for confounding factors with both a case-control and a propensity score–adjusted multivariate analysis. In addition, these results were from a tertiary care Veterans Affairs hospital, where largely high-risk, male patients are treated. Generalizing these results to other populations should be approached cautiously. Finally, although all of our surgeons were proficient in LVHR, each surgeon’s experience, expertise, and technique may have an effect on outcomes. Other studies have indicated that surgeon experience, expertise, technique, and case volume may have an effect on outcomes. Our propensity score–adjusted multivariate model adjusted for the surgeon, which may take into account experience, expertise, and technique.
Standard laparoscopic repair of PVHs is associated with a reduced rate of SSIs but predisposes to bulging and port-site hernia recurrences. Prospective randomized trials to clarify the outcomes and the role of laparoscopic repair of PVHs are needed. In addition, there is a need to identify techniques to mitigate the risk of port-site hernia recurrences and bulging with laparoscopic repair, and this warrants further investigation.
Corresponding Author: Mike K. Liang, MD, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, 2002 Holcombe Blvd, OCL (112), Houston, TX 77030 (email@example.com).
Accepted for Publication: May 21, 2013.
Published Online: September 4, 2013. doi:10.1001/jamasurg.2013.3587.
Author Contributions: Study concept and design: Liang.
Acquisition of data: Berger.
Analysis and interpretation of data: Liang, Li, Davila, Hicks, Kao.
Drafting of the manuscript: Liang.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Liang, Davila, Hicks.
Obtained funding: Liang.
Administrative, technical, or material support: Liang, Berger.
Study supervision: Liang, Kao.
Conflict of Interest Disclosures: None reported.
Previous Presentation: This study was presented in part at the 2013 Association of VA Surgeons Annual Meeting; April 22, 2013; Milwaukee, Wisconsin.