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Reprint requests: John P. Fischer, MD, MPH, Division of Plastic Surgery, Department of Surgery, Penn Presbyterian Medical Center at the University of Pennsylvania, Perelman School of Medicine, 2nd Floor Wright-Saunders Building, 51 N 39th Street, Philadelphia, PA 19104.
Operative intervention to correct incisional hernia affects 150,000 patients annually, with 1 in 3 repairs recurring within 9 years. The aim of this study was to compare the incidence of incisional hernia and postoperative complications in elective midline laparotomy patients after the use of prophylactic mesh placement and primary suture closure.
Methods
A systematic review was performed to identify studies comparing prophylactic mesh placement to primary suture closure in elective, midline laparotomy at index abdominal aponeurosis closure. The primary outcome was incisional hernia. Secondary outcomes included postoperative complications.
Results
Fourteen studies were included (2,114 patients), with 1,152 receiving prophylactic mesh placement. Prophylactic mesh placement decreased the risk of incisional hernia overall when compared to primary suture closure (relative risk = 0.15; P < .00001) and in trials using only polypropylene mesh versus 4:1 primary suture closure (relative risk = 0.15; P = .003). Prophylactic mesh placement reduced the risk of incisional hernia regardless of mesh location or composition: onlay (relative risk = 0.07; P < .0001), retrorectus (relative risk = 0.04; P = .002), and preperitoneal (relative risk = 0.18; P = .02). Prophylactic mesh placement increased risk of seroma overall (relative risk = 1.95; P < .0001), onlay (relative risk = 2.43; P = .01) and preperitoneal (relative risk = 1.47; P = .01) but not retrorectus plane (relative risk = 1.55; P = .26). Polypropylene mesh increased seroma risk only in the onlay position (relative risk = 2.77; P = .04). Prophylactic mesh placement patients are at increased risk for chronic wound pain compared to primary suture closure (relative risk = 1.70; P = .03).
Conclusion
Prophylactic mesh placement is associated with an 85% postoperative incisional hernia risk reduction when compared to primary suture closure in at-risk patients undergoing elective, midline laparotomy closure. This technique appears to be safe with comparable complication profiles, barring an increased risk of seroma, especially with the onlay technique, and the possibility for an increased risk of chronic pain. Despite this verification, evidence from large domestic trials that sufficiently addresses major knowledge gaps is simply lacking.
Incisional hernia (IH) after midline laparotomy and other anterior abdominal wall operations is a common, challenging problem for all surgeons.
Obesity, an extremely prevalent health condition in the United States, represents a portion of the high-risk population in which up to 70% of patients experience IH after open operations.
Hernia repairs are associated with significant financial losses and remain a major public health issue.
Various methods of suture closure and mesh reinforcement have been used to treat IH and restore abdominal wall integrity. Despite advances in IH repair, recurrence rates remain unacceptable (12–54%), and those who experience recurrence are susceptible to a vicious cycle of morbidity, because each subsequent repair presents greater technical challenges and an increased risk for recurrence and morbidity.
Failure to effectively close the abdominal wall after open operations leaves the patient at risk for developing IH, an extremely unfavorable health state.
Cost-utility analysis of the use of prophylactic mesh augmentation compared with primary fascial suture repair in patients at high risk for incisional hernia.
Patients suffering from IH experience deterioration in quality of life (QoL), including disability, pain, and long-term dysfunction and dissatisfaction.
Cost-utility analysis of the use of prophylactic mesh augmentation compared with primary fascial suture repair in patients at high risk for incisional hernia.
This proactive viewpoint is paramount for developing strategies to prevent costly iatrogenic complications after abdominal operations. Prophylactic mesh placement (PMP) involves mesh implantation, usually in the onlay or retrorectus positions, at the time of initial abdominal aponeurosis closure to prevent postoperative IH. Recent studies suggest that prevention of IH via PMP may be the solution to this hernia epidemic.
Prevention of incisional hernias by prophylactic meshaugmented reinforcement of midline laparotomies for abdominal aortic aneurysm treatment: a randomized controlled trial.
This systematic review and meta-analysis aimed to assess the overall efficacy of PMP in reducing the incidence of IH when compared to suture closure techniques and assessed the effect of different perioperative PMP compositions and lays while also addressing the incidence of postoperative complications.
Methods
Search strategy
A systematic search of PubMed, MEDLINE via OVID, EMBASE via OVID, Scopus, Cochrane CENTRAL Register of Controlled Trials, and clinicaltrials.org was performed for full-text, randomized controlled trials (RCTs) and prospective cohort studies published after 1995 comparing PMP to traditional primary suture closure (PSC) after elective, midline laparotomy. This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines.
A manual search of relevant articles found from review citations was also performed. The search strategy used for each database is reported in the appendix (supplementary content with a table describing search terms per database). The final search was performed on May 28, 2016.
Study selection
Studies were evaluated by 2 reviewers (Z.B., S.S.), and a third reviewer (M.T.) resolved any discrepancies regarding inclusion. After identifying relevant studies through title and abstract information, studies were selected for inclusion based upon full-text evaluation. Target studies were trials of elective laparotomy patients who were closed with either PMP or PSC. Inclusion criteria included patients between the ages of 18 and 75 years undergoing elective laparotomy with a vertical midline incision and ≥1 IH risk factor (ie, body mass index [BMI] ≥ 25 kg/m2, prior abdominal operation, history of abdominal aortic aneurysm, ≥45 years of age, and smoking or history of chronic obstructive pulmonary disease).
Closure was to be done in a single stage. All PSC techniques were acceptable, as well as all mesh locations, compositions, and fixations were acceptable. Exclusion criteria included prior hernia or existing abdominal mesh, nonelective cases (ie, urgent or emergency), history of metastatic cancer, immunosuppression, active infection, life expectancy <24 months, and pre-existing pregnancy.
Data extraction and assessment of methodologic quality
Two authors (S.S., Z.B.) independently extracted data using a template data extraction sheet, with a third author (M.T.) serving as a tiebreaker when consensus was not achieved. Information gathered included study characteristics, patient demographics, comorbidities, perioperative details, and primary and secondary outcomes. Characteristics included study design, year of publication, geographic location, patient population, and cohort size. Patient demographics and comorbidities included age, sex, BMI, diabetes mellitus, smoking, chronic obstructive pulmonary disease, and cardiovascular disease.
Perioperative details included wound class, suture type, mesh type, mesh placement, mesh fixation method, and postoperative hernia detection method. The primary outcome of interest was incidence of IH. Secondary outcomes included duration of stay, duration of follow-up, surgical site infection, chronic pain, mesh infection, mesh removal, and rate of reoperation. The number of patients recorded at follow-up was used as denominator, instead of the enrollment number. Two authors (S.S., Z.B.) independently assessed the methodologic quality of included RCTs using the Cochrane Collaboration risk-of-bias tool.
Patients were classified according to abdominal incision closure as either PSC or PMP. Patient demographics were reported via standard summary statistics and compared using the Wilcoxon–Mann Whitney test, with significance set to P < .05. Data were pooled for meta-analysis when interventions, patients, and outcomes were sufficiently similar (determined by consensus). A random-effects model was used to pool data. For dichotomous outcomes, we calculated the Mantel-Haenszel risk ratio (RR) and corresponding 95% confidence interval.
Subgroup analyses by mesh location were performed when data were available. Heterogeneity across studies was assessed using the χ2 test. The I2 statistic was used to quantify heterogeneity.
Sensitivity analyses were conducted to explore potential explanations for heterogeneity and the impact on the effect estimate by excluding nonrandomized studies. Publication bias was explored by constructing funnel plots where appropriate (ie, when there were ≥10 studies in a pooled analysis).
All analyses were conducted in Stata IC software (release 13.1; StataCorp LP, College Station, TX) and figures generated with RevMan software (version 5.3; The Cochrane Collaboration, London, UK).
Results
Fourteen studies (11 RCTs and 3 prospective cohort trials, including 2,114 patients) met the inclusion criteria (Table I, Fig 1).
Prevention of incisional hernias by prophylactic meshaugmented reinforcement of midline laparotomies for abdominal aortic aneurysm treatment: a randomized controlled trial.
A prospective, randomized, multicenter trial of Surgisis Gold, a biologic prosthetic, as a sublay reinforcement of the fascial closure after open bariatric surgery.
In total, 2,069 participants were analyzed, of which 1,128 received PMP. Weighted means for the studied populations were 52.9 ± 14.98 years old, 44.95 ± 29.81% men, BMI 41.7 ± 9.27 kg/m2, and duration of follow-up 25.67 ± 9.92 months. There were no significant differences in demographics, comorbidities, duration of stay, or duration of follow-up between cohorts (Table II).
Prevention of incisional hernias by prophylactic meshaugmented reinforcement of midline laparotomies for abdominal aortic aneurysm treatment: a randomized controlled trial.
A prospective, randomized, multicenter trial of Surgisis Gold, a biologic prosthetic, as a sublay reinforcement of the fascial closure after open bariatric surgery.
The Timmermans et al39 study provided only short-term results (1-month follow-up); due to this, the data were not included in the quantitative meta-analysis.
N/A
1
PMP-onlay, retrorectus
373
Overall study quality for RCTs was assessed using the Cochrane's risk-of-bias tool.
Prevention of incisional hernias by prophylactic meshaugmented reinforcement of midline laparotomies for abdominal aortic aneurysm treatment: a randomized controlled trial.
A prospective, randomized, multicenter trial of Surgisis Gold, a biologic prosthetic, as a sublay reinforcement of the fascial closure after open bariatric surgery.
Prevention of incisional hernias by prophylactic meshaugmented reinforcement of midline laparotomies for abdominal aortic aneurysm treatment: a randomized controlled trial.
A prospective, randomized, multicenter trial of Surgisis Gold, a biologic prosthetic, as a sublay reinforcement of the fascial closure after open bariatric surgery.
A prospective, randomized, multicenter trial of Surgisis Gold, a biologic prosthetic, as a sublay reinforcement of the fascial closure after open bariatric surgery.
Prevention of incisional hernias by prophylactic meshaugmented reinforcement of midline laparotomies for abdominal aortic aneurysm treatment: a randomized controlled trial.
(67.7%) did not report specific time points (supplementary content, risk of bias summary; Newcastle-Ottawa scale summary).
The three observational studies were evaluated using the Newcastle-Ottawa quality assessment scale and all were rated as low risk for selection and comparability parameters.
A prospective, randomized, multicenter trial of Surgisis Gold, a biologic prosthetic, as a sublay reinforcement of the fascial closure after open bariatric surgery.
Prevention of incisional hernias by prophylactic meshaugmented reinforcement of midline laparotomies for abdominal aortic aneurysm treatment: a randomized controlled trial.
Ten of the 14 studies used polypropylene (PP) mesh (71.4%), one used absorbable polyglactin mesh (7.1%), and 3 used biologic mesh (21.4%) (Table III). Light-weight PP mesh (26–40 g/m2) was used in 2 studies,
Prevention of incisional hernias by prophylactic meshaugmented reinforcement of midline laparotomies for abdominal aortic aneurysm treatment: a randomized controlled trial.
and the remaining PP-mesh studies did not specify weight. Of the 3 biologics, bovine pericardium (Peri-Guard, Synovis Surgical Innovations, St. Paul, MN), Alloderm (LifeCell Corporation, Branchburg, NJ), and Surgisis Gold (Cook Biotech Inc, West Lafeyette, IN) were placed. Thirteen of the studies specified the exact anatomic location of the mesh, one
Prevention of incisional hernias by prophylactic meshaugmented reinforcement of midline laparotomies for abdominal aortic aneurysm treatment: a randomized controlled trial.
A prospective, randomized, multicenter trial of Surgisis Gold, a biologic prosthetic, as a sublay reinforcement of the fascial closure after open bariatric surgery.
In 5 intervention groups the onlay technique was used, 4 used retrorectus, 4 used preperitoneal, and 1 used intraperitoneal. The onlay method placed the mesh above the anterior rectus sheath, retrorectus between the rectus abdominis muscle and posterior rectus aponeurosis, preperitoneal between the posterior rectus aponeurosis and the parietal peritoneum, and intraperitoneal within the abdominal cavity. Eight studies (57.1%) reported using a PSC 4:1 suture length to incision length ratio. Thirteen studies (92.8%) used a continuous facial closure, and 1 reported an interrupted technique. The suture type used to close the aponeurosis was slowly absorbable monofilament in 8 studies and nonabsorbable monofilament in 7 studies. Suture sizes ranged from 0 to 2. Details of the PSCs and mesh location, fixation, and suture techniques are provided in Table III.
Outcomes assessment
The primary outcome of interest was incidence of IH. Thirteen studies, including 1,589 (75.2%) patients, reported IH outcome data. One trial published short-term, 30-day postoperative results for 480 patients, where IH was not assessed and would not be assessed until the 6-month time point.
In addition, 45 patients were lost to follow-up, including 30 postoperative deaths unrelated to PMP or PSC complications. Nine of the 13 studies (69.2%) reported using imaging studies to detect IH. The time points for follow-up, however, varied widely.
All studies planned for an end point of at least 14 months (supplementary content, table detailing the clinical and radiological assessments to detect the incidence of IH). PMP significantly decreased the risk of IH development compared to PSC. Ten percent (77/755) of PMP patients developed IH compared to 25% (207/834) of PSC patients (RR 0.23; P < .0001). However, statistically significant heterogeneity was detected for this comparison (I2 = 72%). A visual inspection of the forest plot identified 2 potential outliers.
A prospective, randomized, multicenter trial of Surgisis Gold, a biologic prosthetic, as a sublay reinforcement of the fascial closure after open bariatric surgery.
A prospective, randomized, multicenter trial of Surgisis Gold, a biologic prosthetic, as a sublay reinforcement of the fascial closure after open bariatric surgery.
) that are not commonly used and do not appear to provide a benefit. A sensitivity analysis excluding these two studies appears to explain the heterogeneity as the I2 value drops to 0%. PMP still significantly reduces the risk of IH compared to PSC.
Additionally, a sensitivity analysis excluding the cohort studies did not have a significant impact on the overall results with IH rates of 2.8% (9/325) and 27.7% (93/335) in the PMP and PSC groups, respectively (RR 0.15; P < .00001) (Fig 2, A; Table IV). The majority of studies placed PP mesh in the PMP cohort and used a 4:1 suture length to wound length closure technique in the PSC cohort. To limit variability between comparisons, an analysis of only these parameters revealed that PP mesh placed in any location significantly decreased the risk of IH development (RR 0.15; P = .0003) when compared directly to 4:1 suture length to wound length PSC (Fig 2, B).
Fig 2(A) Forest plot comparing overall risk of IH in patients receiving PMP versus PSC after a sensitivity analysis. (B) Forest plot comparing risk of IH in patients receiving polypropylene PMP versus 4:1 (SL:WL) PSC. A Mantel-Haenszel random-effects model was used to conduct the meta-analysis, and risk ratios are presented with 95% confidence intervals. (Color version of this figure is available online.)
A subgroup analysis by mesh location revealed that PMP placed in the onlay (RR 0.08; P < .0001) and retrorectus (RR 0.10; P < .0001) positions significantly decreased the risk of IH development. PMP placed in the preperitoneal position did not significantly decrease the risk of IH, with Mantel-Haenszel pooled RR = 0.43 (P = .21). Statistically significant heterogeneity, however, was detected for this comparison (I2 = 75%). A visual inspection of the forest plot identified a potential outlier.
A prospective, randomized, multicenter trial of Surgisis Gold, a biologic prosthetic, as a sublay reinforcement of the fascial closure after open bariatric surgery.
A sensitivity analysis excluding this study appears to explain the heterogeneity as the I2 value drops to 0%. Without this outlier, PMP placed in the preperitoneal position (RR 0.18; P = .02) significantly decreased the risk of IH development. Furthermore, a sensitivity analysis excluding cohort studies had some impact on the overall results. PMP placed in the onlay (RR 0.07; P < .00001), retrorectus (RR 0.04; P = .002), and preperitoneal positions (RR 0.18; P = .02) significantly decreased the risk of IH development (Fig 3, A). To limit variability in the subgroups, an analysis including only meshes composed of PP also revealed a significant decrease in IH regardless of mesh location, onlay (RR 0.08; P < .0001), retrorectus (RR 0.10; P < .0001), and preperitoneal positions (RR 0.18; P = .02) (Fig 3, B).
Fig 3(A) Forest plot comparing risk of IH in patients receiving PMP versus PSC, with subgroups analyzed by mesh location (onlay, retrorectus, preperitoneal) after a sensitivity analysis. (B) Forest plot comparing risk of IH in patients receiving polypropylene PMP versus PSC, with subgroups analyzed by mesh location. A Mantel-Haenszel random-effects model was used to conduct the meta-analysis, and risk ratios are presented with 95% confidence intervals. (Color version of this figure is available online.)
The use of PMP was found to be associated with a significantly increased rate of postoperative seroma. Twelve percent (117/984) of PMP patients had a postoperative seroma compared to 5% (41/768) of PSC patients (RR 1.91; P < .0001). A sensitivity analysis excluding cohort studies did not significantly alter the results. Eleven percent (101/883) of PMP patients had a postoperative seroma compared to 5% (33/631) of PSC patients (RR 1.95; P = .001) (Fig 4, A). PMP in the onlay (RR 2.43; P = .01) and preperitoneal positions (RR 1.47; P = .01) significantly increased the risk of postoperative seroma. Mesh placed in the retrorectus position (RR 1.55; P = .26) did not increase the risk of seroma (Fig 4, B). Limiting the previous analysis to only PP mesh revealed that PP mesh also increased seroma risk when placed in the onlay position (RR 2.77; P = .04) but not in the retrorectus (RR 1.37; P = .30) or preperitoneal positions (RR 1.46; P = .39) (Table IV).
Fig 4(A) Forest plot comparing overall risk of seroma in patients receiving PMP versus PSC after a sensitivity analysis. (B) Forest plot comparing risk of seroma in patients receiving PMP versus PSC, with subgroups analyzed by mesh location after a sensitivity analysis. A Mantel-Haenszel random-effects model was used to conduct the meta-analysis, and risk ratios are presented with 95% confidence intervals. (Color version of this figure is available online.)
Four studies (28.6%) included chronic wound pain as an outcome measure. PMP patients have a significantly increased risk of chronic postoperative wound pain compared to PSC patients. Twelve percent (38/305) of PMP patients reported chronic wound pain at follow-up compared to 7% (22/317) of PSC patients (RR 1.70; P = .03) (Fig 5). There were no statistically significant differences in other postoperative complications, including surgical site infection, hematoma, wound dehiscence, or other medical complications (supplementary content, table showing postoperative complications per study).
Fig 5Forest plot comparing overall risk of chronic pain in patients receiving PMP versus PSC. A Mantel-Haenszel random-effects model was used to conduct the meta-analysis, and risk ratios are presented with 95% confidence intervals. (Color version of this figure is available online.)
PMP appears to significantly reduce the risk of IH in at-risk patients after elective, midline laparotomy. While offering a comparable complication profile compared to PSC alone, PMP increases the risk of seroma formation, especially in the onlay position, and may increase the risk of chronic postoperative pain. The existing body of literature related to PMP overwhelmingly supports its use as a technique to reduce IH across various at-risk open operation patient populations, including abdominal aortic aneurysm, obese, and bariatric cohorts. PMP appears to decrease the incidence of IH independent of mesh location (ie, onlay, retrorectus, or preperitoneal tissue planes). Data were not sufficient to detect incidence of chronic pain by mesh location.
Incidence of hernia
The main outcome of this review revealed that PMP significantly reduces the risk of IH when compared to PSC. This outcome was statistically significant when analyzed with all variations of PMP and PSC but also remained significant when comparing only PP mesh to 4:1 PSC technique, when comparing all PMP subgrouped by location and when comparing only PP mesh subgrouped by location (Table IV). By analyzing the data in this way, we were able to explore if any differences in mesh material, mesh position, or PSC technique had any impact on the development of IH.
Ten RCTs and 3 prospective consecutive cohort studies provided data for this outcome measure.
Prevention of incisional hernias by prophylactic meshaugmented reinforcement of midline laparotomies for abdominal aortic aneurysm treatment: a randomized controlled trial.
A prospective, randomized, multicenter trial of Surgisis Gold, a biologic prosthetic, as a sublay reinforcement of the fascial closure after open bariatric surgery.
Analysis based on 8 randomized studies (Fig 2, A) indicated that the overall quality of available evidence supporting this outcome was low due to unknown or high risk of detection bias and sparse data. Although patient demographics were similar between studies and cohorts, other study details, such as technique and materials, varied greatly. Due to this heterogeneity, it is unknown what the most efficacious material or technique may be to prevent IH. Data analysis revealed that all 3 locations subgroups (ie, onlay, retrorectus, and preperitoneal) were significantly associated with IH risk reduction, with the onlay and retrorectus positions being associated with the most relative efficacy.
Postoperative complications
Between the PMP and PSC cohorts, seroma remained the only postoperative complication that was significantly different between groups. Patients with PMP were almost twice as likely to experience postoperative seroma, but upon subgroup analysis, we revealed this relationship exists only in the onlay and preperitoneal mesh positions. To explore this further, a pooled analysis performed on studies that included only PP mesh revealed that risk of seroma was substantially higher in the onlay position, and there was no evidence of increased risk with PP mesh placed in the retrorectus or preperitoneal planes. Therefore the type of mesh may play a role in the development of seroma.
These results are in concordance with other mesh studies that have shown mesh placed in more superficial positions are associated with seroma.
The majority of seromas in this study were managed conservatively or with percutaneous drainage, only one seroma led to reoperation and partial mesh removal due to suspected infection, where cultures later proved to be negative. In a PMP cost-utility analysis, survey data from 300 individuals indicated that seroma was one of the most favorable health states after abdominal operations with a visual analog score of 67.4 out of 100 (perfect health), indicating that seroma mattered less to patients when compared to other complications.
Cost-utility analysis of the use of prophylactic mesh augmentation compared with primary fascial suture repair in patients at high risk for incisional hernia.
Outside of seroma and chronic pain, there were no differences in other postoperative complications, including superficial infection, deep infection, hematoma, wound dehiscence, and reoperation. Furthermore, no clear definitions were described for any of the postoperative complications. For this reason and lack of standardized complication assessment protocols among the studies, it is likely that complication rates underestimate true occurrences in these patient populations. Although no risk of SSI was found with PMP in this analysis, the introduction of implants in patients has been associated with infection risk and may play an important role as more studies on PMP are performed.
Four studies included chronic wound pain as a secondary outcome and upon pooled analysis, PMP was shown to have a moderate yet significant increased risk of chronic pain compared to PSC.
Prevention of incisional hernias by prophylactic meshaugmented reinforcement of midline laparotomies for abdominal aortic aneurysm treatment: a randomized controlled trial.
A prospective, randomized, multicenter trial of Surgisis Gold, a biologic prosthetic, as a sublay reinforcement of the fascial closure after open bariatric surgery.
The method of data acquisition for pain assessment in these studies, however, lacked standardized pain scales and assessment tools. Consequently, a thorough interpretation of the intensity of postoperative pain was not possible. There is a significant knowledge gap in patient-reported outcomes after PMP intervention. No study has performed long-term QoL, return to work, chronic pain, or abdominal wall function with validated reporting measures. In other words, do the potential long-term risks of mesh symptoms outweigh its presumed benefit? These unanswered questions likely represent barriers to the widespread adoption of PMP to prevent IH.
Application beyond high risk
While target populations in existing studies involve high-risk patients (ie, obesity, connective tissue disorders, malignancy, diabetes, smoking, immunosuppression, malnutrition), additional patient populations may benefit from PMP.
Increased prevalence of abdominal aortic aneurysm in patients undergoing inguinal hernia repair compared with patients without hernia receiving aneurysm screening.
Recent meta-regression analyses suggest that 1 in 8 patients undergoing elective, midline laparotomy of a mixed-risk population will develop postoperative IH.
Cost-utility analysis of the use of prophylactic mesh augmentation compared with primary fascial suture repair in patients at high risk for incisional hernia.
This suggests that PMP may have an even broader indication than originally thought.
Major knowledge gaps
Identification of the most efficacious mesh type in the optimal position remains elusive. Known characteristics of an ideal mesh include inert material, mechanical strain resistance, minimal foreign body reaction, flexibility, infection resistance, protection against visceral adhesion formation, and similar tensile strength to autologous tissue. Several mesh types, including permanent synthetic,
Prevention of incisional hernias by prophylactic meshaugmented reinforcement of midline laparotomies for abdominal aortic aneurysm treatment: a randomized controlled trial.
PREBIOUS trial: a multicenter randomized controlled trial of PREventive midline laparotomy closure with a BIOabsorbable mesh for the prevention of incisional hernia: rationale and design.
meshes have demonstrated effectiveness, yet no one type offers the optimal combination of characteristics. Identifying the best mesh type and location in the prophylactic versus hernia setting poses a unique set of challenges that remains unstudied.
New bioabsorbable meshes, including Bio-A (W. L. Gore and Associates, Inc, Flagstaff, AZ), PHASIX (C. R. Bard, Inc/Davol Inc, Warwick, RI), and TIGR matrix (Novus Scientific, Uppsala, Sweden), offer appropriate tensile strengths and low recurrence rates comparable to synthetics while mirroring the decreased reactivity and infection rates associated with biologics.
Bioabsorbable meshes may offer a unique solution to mesh pain and seroma incidence previously associated with synthetic permanent mesh, because they behave like synthetics and then are resorbed. The PREBIOUS trial is currently evaluating Bio-A mesh with the “sandwich” technique in humans to prevent IH.
PREBIOUS trial: a multicenter randomized controlled trial of PREventive midline laparotomy closure with a BIOabsorbable mesh for the prevention of incisional hernia: rationale and design.
Little data exist, however, and evidence to support the broad application of this mesh class is limited, especially in the prophylactic setting until further research is performed.
Ideal mesh positioning also remains poorly studied, as the onlay, retrorectus (sublay), and preperitoneal (underlay) planes are all associated with differing complication profiles. Onlay mesh offers the simplest, quickest closure and can be considered a generalizable technique adoptable across surgical practices. Possible drawbacks include increased seroma rates, infection rates, and exposure risks, which may be mitigated by patient and mesh selection and tissue management. The Rives-Stoppa technique in the retrorectus plane offers advantages, including even tension distribution, no cutaneous or visceral exposure, and intra-abdominal pressure resistance; however, it poses a significant technical challenge and added time that may lead to poor adaptability among varying surgeons in the prophylactic setting. The preperitoneal position offers similar benefits and technical challenges as retrorectus placement; however, it exposes the mesh to the viscera and subsequent intra-abdominal complications.
Current PMP literature fails to sufficiently address patient-centered outcomes.
Measures including QoL, return to work, chronic pain assessments, and overall functionality will need to be further analyzed to help improve delivery to various patient populations that may benefit from prophylactic mesh placement. Bridging these knowledge gaps will help surgeons to develop PMP clinical decision-making tools and guidelines that can be further personalized based on an individual's baseline risk, comorbidities, and expected postoperative functionality.
PMP has been described in the literature as prophylactic mesh “augmentation.”
Cost-utility analysis of the use of prophylactic mesh augmentation compared with primary fascial suture repair in patients at high risk for incisional hernia.
We believe that the previous adoption of this term to describe fixation of mesh to the abdominal aponeurosis is not accurate, as nothing is becoming larger as a result of the procedure. Instead, we would like to introduce the term “placement” to replace “augmentation” in the literature, because it better describes the action of the operative procedure.
Optimal RCT design
Despite the supporting body of literature highlighting the protective effects of PMP on IH, existing studies remain heterogeneous with several knowledge gaps. The published literature on this topic is limited due to specific surgical indications, narrow patient population, differing mesh types/locations/fixations, and lack of standardized follow-up times and outcome measures. Table V outlines an ideal design for a comprehensive RCT aimed to address these inadequacies.
Table VSuggestions to improve future trials
Include
Purpose/notes
Population
High-risk elective patients
Include all patients with known risk factors (such as BMI ≥25 kg/m2, prior abdominal operation, history of AAA, age >45 years, smoking, or COPD)
Exclusion criteria
Prior hernia or existing abdominal mesh, metastatic cancer, immunosuppression, active infection, life expectancy <24 mo, pregnant women
Mixed-risk elective patients
Identify if low-risk population can benefit from PMP
Patient demographics
Document to control for factors that impact baseline IH risk
Design Details
Block randomization
Block to ensure adequate representation of variables
Multicenter
Recruitment of 10+ large academic centers able to host data coordinating center
Power of trial
Assuming 12.8% and 7% IH formation in the PSC and PMP groups, respectively, a sample of 1,000 equally allocated patients would maintain 82% power for Fischer exact tests and 86% power for log-rank tests; this takes into account 5% loss to follow-up
Operative details
Wound class
Identify if PMP can be used in higher classes of contamination
Index procedure
Stratify risk of outcome measures by procedure type
Laparotomy length
Is the benefit of PMP limited to a particular wound size?
PSC suture material
Absorbable, nonabsorbable, and suture size
PSC SL:WL
4:1 or other
PSC closure method
Loop/continuous/locking/interrupted
Mesh position
Onlay, retrorectus, preperitoneal, intraperitoneal (see methods for definition)
Mesh type
Synthetic compositions versus biologic compositions
Mesh fixation suture
Absorbable versus nonabsorbable
Mesh fixation method
Suture (interrupted tacking/continuous) versus fibrin glue
Closure operative time
For mesh-fixation comparisons
PMP time
For procedure type and mesh-positioning comparisons
PMP team
Did the original surgical team close or get help for PMP
Outcome measures
Incisional hernia
Blinded evaluator performs clinical exam. If positive for IH Imaging using ultrasound to confirm.
Time to incisional hernia
SSO
Minor SSOs defined as those that resolve within 90 days with local wound care alone. Major SSOs require local wound care for >90 days or additional intervention
SSI
Minor SSIs defined as those that resolve within 90 days with local wound care alone. Major SSIs require local wound care for >90 days or additional intervention
Mesh infection
Any mesh infection requiring mesh removal
Mesh removal
Provide indication, operative details, and results of cultures performed
Rehabilitation
Any physical therapy or occupational therapy required
Activity level
Use IPAQ or similar instrument to compare activity level; also, document any activities/careers that increase intra-abdominal pressure
Reoperation
Related to PSC or PMP complication; provide operation details
Chronic pain
Use PROMIS scale; avoid broad definitions of chronic pain
Quality of life
Use accepted QALY tool (HerQLes, Carolinas Comfort Scale)
Duration of follow-up
Defined by most recent clinic visit; only include patient if >2 years
Evaluation timeline
Postoperative evaluations
14 days, 30 days, 3 mo, 6 mo, 1–5 years annually
SL:WL, Suture length to wound length; SSI, surgical site infection; SSO, surgical site occurrence; QALY, quality adjusted life years.
In conclusion, PMP is associated with an 85% postoperative IH risk reduction when compared to traditional suture closure in at-risk patients undergoing elective, midline laparotomy closure. PMP appears to be effective regardless of location. This technique appears to be safe with current data revealing comparable postoperative complication profiles, barring an increased risk of seroma, especially with the onlay technique, and a possible increased risk for the development of chronic pain. Despite this verification, PMP evidence from large domestic pragmatic trials is simply lacking. We expect increased domestic adoption of PMP and subsequent development of strong evidence-based guidelines with the introduction of a dedicated Category III Current Procedure Terminology code (0437T) in July 2016 by the American Medical Association for prophylactic mesh placement.
Cost-utility analysis of the use of prophylactic mesh augmentation compared with primary fascial suture repair in patients at high risk for incisional hernia.
Prevention of incisional hernias by prophylactic meshaugmented reinforcement of midline laparotomies for abdominal aortic aneurysm treatment: a randomized controlled trial.
A prospective, randomized, multicenter trial of Surgisis Gold, a biologic prosthetic, as a sublay reinforcement of the fascial closure after open bariatric surgery.
Increased prevalence of abdominal aortic aneurysm in patients undergoing inguinal hernia repair compared with patients without hernia receiving aneurysm screening.
PREBIOUS trial: a multicenter randomized controlled trial of PREventive midline laparotomy closure with a BIOabsorbable mesh for the prevention of incisional hernia: rationale and design.
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