Prophylactic Mesh During Colostomy Does Not Prevent Hernia

In This Article

Abstract and Introduction

Abstract

Objective: The aim of this study was to determine whether parastomal hernia (PSH) rate can be reduced by using synthetic mesh in the sublay position when constructing permanent end colostomy. The secondary aim was to investigate possible side-effects of the mesh.

Background: Prevention of PSH is important as it often causes discomfort and leakage from stoma dressing. Different methods of prevention have been tried, including several mesh techniques. The incidence of PSH is high; up to 78%.

Methods: Randomized controlled double-blinded multicenter trial. Patients undergoing open colorectal surgery, including creation of a permanent end colostomy, were randomized into 2 groups, with and without mesh. A lightweight polypropylene mesh was placed around the colostomy in the sublay position. Follow up after 1 month and 1 year. Computerized tomography and clinical examination were used to detect PSH at the 1-year follow up. Data were analyzed on an intention-to-treat basis.

Results: After 1 year, 211 of 232 patients underwent clinical examination and 198 radiologic assessments. Operation time was 36 minutes longer in the mesh arm. No difference in rate of PSH was revealed in the analyses of clinical (P = 0.866) and radiologic (P = 0.748) data. There was no significant difference in perioperative complications.

Conclusions: The use of reinforcing mesh does not alter the rate of PSH. No difference in complication rate was seen between the 2 arms. Based on these results, the prophylactic use of mesh to prevent PSH cannot be recommended.

Introduction

Parastomal hernia (PSH) is a common complication after stomal surgery. Though the exact incidence has not been fully established, figures range between a few and 78%.^[1–3] Most PSHs develop within 2 years of surgery but can occur up to 30 years later. Approximately, one third of patients operated for rectal cancer in Sweden have a permanent colostomy, and 24% to 39% of patients with a "temporary" stoma never have it reversed.^[4–6] PSH causes difficulties with stoma dressing and leakage, increases the risk for incarceration, and has a negative impact on the patient's quality of life.^[7–9]

A number of strategies have been proposed to prevent the formation of PSH after primary surgery: choice of stoma placement through versus lateral to the rectus sheath, transperitoneal versus extraperitoneal, and correct sizing of the trephine.^[2,10] None of these seems to reduce the incidence of PSH. Furthermore reported 30-day morbidity and mortality rates of planned repair procedures are 8% to 36% and 0% to 5%, respectively^[11–13] Emergency PSH repair has a reported mortality rate of 11% to 25%.^[14,15] The development of stoma techniques that reduce the risk for PSH is thus a field of research that should be given priority.

Placement of a mesh to prevent PSH formation has been proposed. Eight small and 2 large randomized controlled trials (RCT) have been published during the past 2 decades. Pooled data from these studies show promising results,^[16] though mesh location, choice of mesh material and surgical approach varied.^[17–23] The use of mesh did not increase complication rate, but none of the trials was designed to assess complication. On the contrary, 1 retrospective trial comparing PSH rate before and after the introduction of routine prophylactic mesh around the stoma, at a unit that repeatedly produced top results in the Swedish Rectal Cancer Registry, showed no difference in complication rates between groups.^[24] The Swedish National Board of Health and Welfare classifies the use of prophylactic mesh around stomas as, "Research and Development," because of the weak scientific evidence; larger RCTs comparing prophylactic mesh with no mesh are required.^[25]

In view of this uncertainty, we designed a double-blinded multicenter RCT to evaluate the effects of using a prophylactic mesh around the stoma. The primary aim was to evaluate the PSH rate in both groups, and a secondary aim was to assess the risk for early complications. Our hypothesis was that polypropylene mesh in the sublay position around a colostomy decreases the risk for PSH.

Table 1. Basic Demographic Data.
	Nonmesh Group n = 118	Mesh Group n = 114	P
Age, yrs, range	69.9 (35–89)	69.7 (41–86)	0.877
Sex: male	62 (52%)	74 (65%)	0.056
ASA 1+2*	78 (70%)	82 (74%)	0.578
ASA 3*	34 (29%)	28 (26%)	0.578
Smoker^†	8 (7%)	12 (11%)	0.326
BMI, range	26.3 (18.5–43.7)	26.1 (16.7–37.8)	0.766
Cancer	106 (90%)	106 (93%)	0.392
Operation time, mins, range	287 (84–625)	323 (70–616)	0.019
Planned surgery	118 (100%)	113 (99%)	0.308
Length of stay, d, range	12 (2–44)	12 (4–44)	0.792

Basic Demographic Data in the Trial Population.
*ASA-class was stated in 222 patients.
†Smoking habit was stated in 216 patients. Median values are shown for: age, BMI, operation time and length of stay.

Table 2. Study population vs ''Not included''.
	STOMAMESH Population n = 232	Not Included n = 434	P
Age, yrs, range	69.8	67.5	0.010
ASA 1+2	167 (71.9%)	229 (52.8%)	<0.001
ASA 3	65 (28.1%)	205 (47.2%)	<0.001
Sex: male	135 (58.0%)	217 (50%)	0.020
Planned surgery	231 (99.6%)	337 (77.6%)	<0.001

The group of patients included in the STOMAMESH trial compared with the patients who could have been but were ''Not included'' at 3 hospitals (Sunderby hospital, Umeå University hospital, and Mora hospital) during the inclusion period. Median values are shown for age.

Table 3. Study population vs "Not included" emergency cases excluded.
	STOMAMESH Population n = 231	Not Included n = 337	P
Age, yrs, range	69.8	67.7	0.043
ASA 1+2	166 (71.9%)	200 (59.3%)	0.002
ASA 3	65 (28.1%)	137 (40.7%)	0.002
Sex: male	135 (58.0%)	164 (48.7%)	0.029

Table 4. Hernia rate at one year.
	Nonmesh Group n = 107	Mesh Group n = 104	P
Hernia (judged clinically)	32 (30%)	30 (29%)	0.866
Bulge, no hernia (judged clinically)	18 (17%)	15 (14%)	0.631
Hernia classified 2 and 3 on CT	28 (26%)	25 (24%)	0.748
Hernia classified 1, 2, and 3 on CT	36 (34%)	33 (32%)	0.765

Follow Up at 1 Year Evaluating Presence of Parastomal Hernia.
CT-scan was performed on 99 patients in each group and the findings were classified according to the model by Moreno-Matias.
Bulge was defined as a protrusion around the stoma judged not to be a hernia.

Table 5. Complications at one month.
	Nonmesh Group n = 112	Mesh Group n = 110	P
Overall complications	36 (32%)	38 (34%)	0.668
Surgical complications	31 (28%)	30 (27%)	0.947
Wound infection	16 (14%)	17 (15%)	0.785
Deep infection	9 (8%)	7 (6%)	0.644
Intestinal obstruction	1 (1%)	2 (2%)	0.618*
Stoma necrosis	8 (7%)	5 (4%)	0.570*
Reoperation within 30 days	6 (5%)	7 (6%)	0.783*
Other complications
Acute myocardial infarction	2 (2%)	2 (2%)	1.000*
Pneumonia	1 (1%)	2 (2%)	0.618*
Thrombosis	0	2 (2%)	0.242*
Urinary tract infection	1 (1%)	5 (4%)	0.116*

Complications at the 1-Month Follow Up in the Trial Population.
*The assumption for the x ² test was not fulfilled in these comparisons and Fischer exact test was used.