Received date: January 25, 2012; Accepted date: March 27, 2012; Published date: March 28, 2012
Citation: Gad MA, Saber A, ElGazzaz G (2012) Risk of Infection and Recurrence over Prolonged Follow up in Patients Undergoing Ventral Hernia Repair with Underlying Sepsis, Concomitant Bowel Injury or Resection - Can the Use of Synthetic Mesh be Justified? Surgery 2:111. doi: 10.4172/2161-1076.1000111
Copyright: © 2012 Gad MA, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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Introduction: The incidence of hernia in a laparotomy incision has been reported to reach up to 20% percent in clean, uncomplicated cases and believed to be higher in the setting of a contaminated operative field, and comorbidity.
Objectives: The authors evaluated the risk of infection and hernia recurrence after repair with non-absorbable mesh.
Methods: A retrospective review of outcome of all patients who underwent mesh repair for ventral hernias with underlying peritoneal sepsis or during a procedure with bowel anastomosis or repair. Long-term evaluation of outcome included intra-peritoneal or wound infection the need for mesh excision or recurrence and quality of life.
Results: Patients with a recurrence (R) and those without a recurrence (NR) had similar, gender, BMI and ASA. The two groups were also comparable with regards to re-admission rate, peri-operative steroid use and the use of drains. A significantly greater proportion of (R) had hypertension, diabetes, and emergency surgery when compared with (NR).
Conclusion: Frequency of mesh infection with the use of non-absorbable mesh in managing ventral hernia with underlying sepsis, during bowel resection or repair is similar to that during isolated ventral hernia repair with mesh.
The incidence of hernia in a laparotomy incision has been reported to reach up to 20% in clean, uncomplicated cases . The risk of developing a hernia at any site is believed to be even higher when surgery is performed in the setting of a contaminated operative field, seroma, frank wound infection, preoperative radiation, steroid use and comorbidity such as malnutrition, diabetes, obesity, ulcerative colitis, Crohn’s disease, and cancer [2,3]. For ventral hernias (VH), repair with mesh is considered to be the standard treatment  and historically, there has been reluctance to use nonabsorbable synthetic mesh for repair of abdominal-wall defects in an operative field in which the presence of open bowel is accompanied by the potential for contamination [5,6].
Biosynthetic meshes are the newest tool available to surgeons and they could have a role in ventral hernia repair in a potentially contaminated field . The use of polypropylene mesh may increase complication rates when the mesh is placed directly over viscera or the operative site has been irradiated or contaminated with bacteria [1,8].
In the present study, the authors evaluated the risk of infection and hernia recurrence after repair with non-absorbable mesh in patients undergoing bowel procedures or explored for peritonitis, which are traditionally classified as clean contaminated or dirty procedures and evaluated long term outcomes for these patients.
A retrospective review of outcomes of all patients who underwent mesh repair for ventral hernias (VH) in the surgical department at Suez Canal University Hospitals, Ismailia-Egypt between December 2000 and January 2009 was performed. Data relating to the type and size of mesh used is collected. A retrospective review of data of all patients included in the study was hence performed.
Only patients who underwent VH repair with underlying peritoneal sepsis or during a procedure with bowel anastomosis or repair were included into the study. Patients without intra-abdominal sepsis, bowel repair or resection were excluded. Patient demographics, medical and surgical history, size of fascial defect, use of drain, type of mesh used and surgical technique used were reviewed. The mesh used was Prolene mesh ( Ethicon Egypt) and was fixed as onlay fashion. Onlay mesh repair was performed after primary closure of the fascial defect. The advantage of a primary fascial closure is to avoid the contact between the underlying viscera and the prosthetic material. The edges of mesh were fixed to the underlying fascia by eight staples or more according to fascial defect size [4,6].
Postoperative morbidity was reviewed from patient’s records maintained during out-clinic visits. In order to identify factors that might be associated with recurrence, patients who developed a recurrence (R) were compared with those that did not get a recurrence (NR). The frequency of deep seated mesh associated infections manifested by the development of a tender swelling or abscess associated with a discharging sinus requiring drainage or mesh excision was also determined.
Long-term evaluation of outcome
In order to obtain additional information pertaining to the need for mesh excision or recurrence and quality of life, over the long term, patients were contacted via regular visits to determine episodes of infection and recurrence of the hernia detected by the patients and confirmed by a physician at a recent visit. Assessment of quality of life was performed using the Cleveland Global Quality of Life (CGQL) score which includes three items: current quality of life (QOL), current health (QOH), and current level of energy (QOE). Each component was graded on a scale of 0-10 in which 0 was the worst and 10 was the best possible score. The final CGQL score was then calculated by dividing the total by 30 .
Summaries of quantitative data are in the form ‘mean +/- standard deviation’ while summaries of categorical data are in the form ‘frequency (%)’, using chi-square or Fisher’s exact tests. An association between study variables and the likelihood of recurrence was assessed using logistic regression to produce odds ratios with 95% confidence intervals. Exact time of recurrence was unable to be determined in all cases, so adjustment for patient follow-up time was performed through covariate adjustment in the logistic regression rather than through time-to-event analyses. Multivariable models for recurrence and infection was constructed using variables for which covariate adjustment was desired.
Eighty patients met the inclusion criteria 48 patients (60%) were females and the mean age of the patients was 61 (S. D 12.5) years. Median body mass index (BMI) was 27 kg/m2 (IQR 26,33). Diagnoses included bowel strangulation (n=36), iatrogenic or inevitable bowel injuries due to severe adhesions (n=24), underlying peritonitis or sepsis (n=14), and malignant bowel obstruction (n=6) (Figure 1). Median follow up was 3.8 years (Iyr. 1.7-8.1). Overall wound infection rate was 15% and recurrence rate 38.8% over the period of follow-up. Thirty eight patients underwent elective surgery and 42 patients underwent emergency surgery. After elective surgery, hernia recurrence occurred in 12 (31.6%) patients, while after emergency surgery recurrence occurred in 23 (54.8%) patients (p=0.001).
Comparison between R and NR groups
Patients with a recurrence (n=35) and those without a recurrence (n=45) had similar age (p=0.9), gender (p=0.3), BMI (p=0.8) and ASA (p=0.14). The two groups were also comparable with regards to re-admission rate (p=0.4), peri-operative steroid use (p=0.15) and use of drains (p=0.9). A significantly greater proportion of (R) had hypertension (p=0.01), diabetes (p=0.04), and emergency surgery (p=0.001) when compared with (NR). There was no significant difference between the two groups for renal (p=0.14), pulmonary (p=0.8), or cardiac comorbidities (p=0.4) and history of smoking (p=0.5). As may be expected, the size of the fascial defect in (R) patients was significantly larger than for (NR) where the mean area of fascial defect in square cm were 155.5 ± 124.9 and 94.5 ± 82.1 respectively as the mean length: 11.6 ± 5.5 cm, mean width: 8.9 ± 5.1 cm (p=0.02). Patients who developed a recurrence were more likely to have developed a wound infection at surgery (p=0.001). A significant proportion of patients who developed a recurrence underwent emergency surgery (23 out 35 patients with recurrence), 65.7% when compared with those who did not develop a recurrence (n=45 patients). All patients had a drain placed, for variable durations (Table 1).
|Age||61.2 ± 12.5||61.6 ± 12.9||0.9|
|Gender||Male||14 (43.8%)||18 (56.2%)||?|
|Female||19 (39.6%)||29 (60.4%)|
|Body mass index||27.5 ± 6.3||27.9 ± 5.4||0.8|
|ASA class||2.0 ± 0.9||2.3 ± 0.8||0.14|
|Comorbidity||Hypertension||13 (43.3%)||17 (56.7%)||0.01*|
|Diabetes||5 (33.3%)||10 (66.6%)||0.04*|
|Renal||1 (25.0%)||3 (75.0%)||0.14|
|Pulmonary||14 (63.6%)||8 (36.4%)||0.8|
|Cardiac||13 (54.2%)||11 (45.8%)||0.4|
|Any comorbidity||25 (51.0%)||24 (49.0%)||0.017|
|Fascial Defect (mean area cm2)||94.5 ± 82.1||155.5 ± 124.9||0.02*|
|Perioperative steroid use||12 (48.0%)||13 (52.0%)||0.15|
|Smoking history||14 (66.7%)||7 (33.3%)||0.5|
|Re-admission||3 (30%)||7 (70%)||0.4|
|Emergency operation||18 (40%)||23 (83.3%)||0.8|
*indicates significant difference
Table 1: Patient Characteristics.
Nine patients (11.3%) developed a mesh infection during the period of follow up, six of them followed by hernia recurrence. Five of these patients (55.6%) required readmission for excision of the mesh.
Long term outcomes
Fifty-two (65%) patients were successfully contacted. Results for the remaining patients were not available. Median time of follow up for the 52 patients from the date of operation to the date of our attendance was 4.3 years (IQR 1.8-8.6). Three out of the nine patients with mesh infection reported delayed mesh infection 5-17 months after surgery during the follow up. One of them experienced many episodes of infections followed by mesh excision whereas the other two were treated conservatively. Five of the contacted patients had hernia recurrence diagnosed by a surgeon and were included to the total number of recurrences (n=35) (Table 2).
|Patients satisfied with results of surgery||18(64.3%)||18(75.0%)||0.2|
|Quality of life||8.0 ±1.9||7.0 ±2.3||0.1|
|Quality of health||8.1 ± 2.0||7.0 ± 2.2||0.08|
|Quality of energy||7.3 ± 2.3||6.3 ± 2.3||0.2|
|quality of happiness||8.9 ± 1.8||7.8 ± 2.6||0.07|
|CGQL||0.8 ± 0.2||0.7 ± 0.2||0.1|
Table 2: Quality of life.
Thirty-six patients (69.2%) of contacted patients were satisfied with the results of their surgery. The CGQL score for patients with recurrent hernia was less than non-recurrent patients although this did not reach statistical significance (p=0.1). Also there was no significant difference in patients satisfaction after surgery between recurrent and non-recurrent patient (p=0.2).
The use of mesh could permit a reduction in the tension developed on fascial sutures placed for repair of hernias especially where there is significant separation or frank loss of fascia . Synthetic mesh has long been used for repair of hernias in selected cases and currently several varieties of mesh are available [1,8].
The risk of associated wound infection during elective or emergency colorectal surgery may deter surgeons from using a mesh for the repair of primary or recurrent ventral hernia, possibly increasing the risk of recurrence . Wound infections have been reported to occur in 2 to 35 percent of patients after colon resection, the likelihood of infection being greater in the case of an emergency procedure . The incidence of mesh related wound infection is variably reported [2,3,13] and may be as high as 100% . In the absence of contamination, the reported infection rate for mesh repair of hernias is 0.8–10 percent . Thus, it is understandable that the use of mesh in potentially contaminated wounds has been strongly discouraged. There is however a dearth of data evaluating long term outcomes for patients undergoing the procedure [2,4]. Although some authors have urged abandonment of the use of mesh for repairs in which open bowel is present or encountered and in contaminated fields [15,16], some series question this consensus. Vix et al.  reported that non-absorbable mesh can be used safely for hernia repair in a contaminated field if placed in the retro-muscular pre-fascial plane.
This study sought to contribute to the debate concerning the safety and efficacy of mesh repair of incisional hernias in the contaminated operative field and to expand the scope of this important discussion. Since these patients were evaluated in our study over a median follow up of 3.8 years, we were able to accurately determine the risk of infection and recurrence over a prolonged period. A large proportion of these patients were further contacted that helped us determine the self-reported incidence of these complications over the long term for these patients.
The recurrence rate for all patients undergoing ventral hernia repair in contaminated operative field was 43.7% and wound infection rate was 15% (12 patients) in our study. For the 38 patients who underwent elective surgery, the hernia recurred in 12 patients (31.6%) after a median follow-up of 3.8 years as determined at office visits.
Because of our preference to avoid the use of mesh in like contaminated situations unless adequate tissue approximation is not possible with sutures placed during abdominal wall closure, the high rate of recurrence of the hernia in these patients may be a reflection of the selective use of mesh in complex procedures associated with significant abdominal wall defects. A greater proportion of patients who developed a recurrence (35 patients) had an emergency procedure, a larger sized fascial defect and wound infection when compared with those who did not develop a recurrence. Recurrence was also associated with co-morbid disease conditions such as diabetes, and hypertension.
Emergency surgery may be expected to be associated with a greater risk of recurrence since patients are expected to be in a suboptimal clinical state when compared with those undergoing elective surgery. Previous studies have reported that the presence of one or more comorbidities predispose patients to development of hernia recurrence . An association between hypertension and diabetes mellitus and poor wound healing and the development of mesh infection has been described [18,19]. A greater proportion of patients in our study who developed a recurrence had these comorbidities thus suggesting that impaired wound healing in these patients may have been contributory.
A body mass index of over 30 kg/m2 has been described to be a known risk factor for the development of ventral hernia due to delayed wound healing, an impaired pulmonary function and a high intraabdominal pressure [3,17] but these co-morbidities are not an absolute contraindication to the use of mesh . In our group of patients, the majority of the patients were obese with little of them being considered overweight. There was no significant difference in the proportion of obese patients in the (R) and (NR) groups.
The strength of this study lies in the fact that outcomes are reported for a large number of patients undergoing repair of ventral hernia with non-absorbable mesh during contaminated bowel surgery. Although outcomes pertaining to mesh infection and recurrence were retrospectively derived, these data were obtained by careful records of patients who continued to have evaluation in the office at our institution and are hence likely to be accurate. The finding that the infection rate for non-absorbable mesh was 15% (12 patients) even in this selected group of patients undergoing complex operations, suggests that the use of non-absorbable mesh during elective colonic surgery may be safe and similar to that reported for patients not undergoing bowel surgery during hernia repair.
Frequency of mesh infection with the use of non-absorbable mesh in managing ventral hernia with underlying sepsis, during bowel resection or repair is similar to that during isolated ventral hernia repair with mesh. Comorbidity, duration of follow up, emergency operations, size of area covered and infection are independent factors associated with recurrence. Regarding patient satisfaction, CGQL score with recurrent hernia was less than non-recurrent patients although this did not reach statistical significance .