Alternatives in the treatment of abdominal rectus muscle diastasis : an evaluation

Abstract

Introduction: Abdominal rectus diastasis (ARD) is defined as a widening of the distance between the two rectus muscles located on either side of the Linea Alba (LA). A width of more than 3 cm is, in this thesis, considered as pathological. There are several reasons why ARD occurs, where pregnancy is one of the most common. Genetic variations in collagen composition, massive weight loss, and previous abdominal surgery are others. Patients with ARD usually perceive no pain at rest whereas discomfort, pain, corset instability and bulging of the abdominal wall are symptoms appearing during physical activity. Conclusive data regarding the most appropriate treatment of ARD are sparse, and studies with focus on abdominal wall function and quality of life after repair are lacking. Furthermore, no reliable data exist regarding evaluation of patients with ARD prior to surgery and the relevance of specific symptoms, width of ARD and abdominal wall strength.

The overall aim of the present thesis was to evaluate the outcome of two surgical methods with regard to relapse of ARD; repair with a retromuscular mesh or double row self-retaining suture. Quality-of-life, pain and abdominal muscle strength were important secondary endpoints in the outcome of repair. Secondary aims were to evaluate: the effects of a dedicated training programme on symptoms and complaints from ARD; imaging and measurements of the ARD width prior to surgery; and to develop a reliable method for evaluation of abdominal wall strength.

Material and methods: Study I. The validity and reliability of the Biodex System-4, was tested in ten healthy volunteers and ten patients with ARD ≥3 cm. The reliability of isokinetic and isometric muscle strength was assessed by test-retest with one week in between. Validity was tested by IPAQ (International Physical Activity Questionnaire) and VAS-assessment of patient-perceived muscle strength. Study II. The width of ARD was evaluated clinically, with CT-scan and intra-operatively in 55 patients. Agreement between these modalities was evaluated to determine the most relevant measurement. Study III. Early complications during the initial three postoperative months were monitored in 56 patients of whom 29 were randomised to repair with a retromuscular mesh and 27 to the Quill™ suture technique. All patients presented with an ARD wider than 3 cm. Study IV. The same 56 patients randomised to surgery as in Study III were compared to 30 patients assigned to a training programme. Follow-up for the operated patients was at 1 year while training outcome was studied after the stated period of 3 months.

Results: The reliability of the Biodex System-4 was excellent as shown by ICC (Intra Class Correlation) statistics. The internal validity was excellent when compared to VAS using Spearman’s test. The external validity showed no correlation between IPAQ and isometric muscle strength using the Kendall-Tau test (Study I). Evaluation of the three methods to assess ARD showed a strong agreement (high CCC; Concordance Correlation Coefficient) between the clinical and intraoperative measurements whereas CT-scan and intraoperative measurements did not show agreement (low CCC). CT measurements underestimated the width of the ARD (Study II). Minor complications were observed three months after surgery. No significant difference between the two surgical groups in terms of early complication and perceived pain was observed. Patients in the mesh group experienced greater improvement in abdominal muscle strength (Study III). One year after surgery one recurrence was documented in the Quill group and five encapsulated seromas were distributed with no difference between the two surgical groups. Biodex System-4 showed significant improvement in all muscle strength modalities with the three methods. Quality-of-life (SF-36) domains were all significantly improved one year after surgery (p<0.001) with the exception of bodily pain (BP) in the physiotherapy group after three months of training (Study IV).

Conclusions: The prospective randomised trial has shown that patients with an ARD wider than 3 cm have physical symptoms and poorer quality of life than an age-matched Swedish population. Surgical intervention improves patient comfort and improves quality of life. There is no difference between the Quill technique and retromuscular mesh in the effect on abdominal wall stability, with a similar complication rate one year after surgery. Dedicated training strengthens abdominal muscles objectively but does not improve perceived muscle strength or pain in the abdominal wall.