Observations on diagnostic reliability and the surgical treatment of abdominal rectus diastasis
Authors: Swedenhammar Ebba 
Published: September 2024

<p dir="ltr">Background</p><p dir="ltr">Abdominal rectus diastasis (ARD), a condition commonly seen after pregnancy or significant weight loss or resulting from abnormal connective tissue composition can lead to functional disability, abdominal and/or back pain, instability of the trunk, and reduced quality-of-life. By evaluating surgical techniques, function tests, and long-term results, we aimed to improve patient care and outcome. This series of papers investigates various surgical and functional approaches to improve patient outcome after ARD repair and massive weight loss reconstructive surgery. Today there are no objective measurement tools to assess the impact of ARD on patient function and quality-of-life, in particular a tool that correlates with self-reported problems.</p><p dir="ltr">Methods and Materials</p><p dir="ltr">Study I: A retrospective cohort study comparing the outcomes of abdominoplasty in three patient groups operated on by general surgeons (Groups A and C) and plastic surgeons (Group B) with varying levels of experience. Group C was assessed after standard management guidelines were introduced. Statistical analyses included X2-test, Fisher's exact test, logistic regression, and ANOVA.</p><p dir="ltr">Study II: A prospective randomised study in which 57 patients were assigned to ARD repair using either Quill self-retaining sutures or retro muscular mesh. The patients were contacted a median of five years after surgery. Long-term outcomes, including recurrence, quality-of-life (QoL), pain, and muscle strength, were assessed using SF-36 and the Ventral Hernia Pain Questionnaire (VHPQ).</p><p dir="ltr">Study III: An experimental cross-sectional cohort study evaluating the reliability of surface electromyography (SEMG) performed during isometric abdominal muscle strength testing. The study included ARD patients and age-, BMI-, and sex- matched controls.</p><p dir="ltr">Study IV: A cross-sectional study with a test-retest design to assess the reliability, validity, and feasibility of the five-time sit-to-stand (5-STS) test from different chair heights in women with and without ARD. Convergent validity was evaluated using correlations with clinically relevant measurements.</p><p dir="ltr">Results</p><p dir="ltr">Study I: A significant reduction in early complication rate was seen after improved surgical training and the introduction of standard guidelines. Group C (after training and guidelines), despite having more comorbidities, showed the lowest complication rate (19%) compared to Groups A (70%) and B (44%).</p><p dir="ltr">Study II: No recurrence of ARD was observed over a median follow-up of five years. Both surgical methods improved Qol and reduced pain, with no significant differences between the groups. The suture technique is recommended due to its lower risk for complications and due to discomfort after the mesh method.</p><p dir="ltr">Study III: SEMG measurements demonstrated moderate to excellent reliability in assessing muscle activation and fatigue during isometric testing. SEMG provided additional insights into muscle function, correlating significantly with various clinical measures such as back pain and body perception.</p><p dir="ltr">Study IV: All 5-STS tests showed moderate to excellent reliability. The standard chair height (43 cm) version was the most suitable for assessing functional performance in women with ARD, showing strong correlations with ARD severity, body perception, and QoL.</p><p dir="ltr">Conclusions</p><p dir="ltr">Study I: Greater surgical experience and the introduction of standard guidelines significantly reduces early complications in abdominoplasty for massive weight loss, improving patient safety and outcomes.</p><p dir="ltr">Study II: ARD repairs using either double-row self-retaining sutures or retro- muscular mesh provide stable long-term results with no recurrence. The less invasive suture technique is recommended due to its lower complication risk.</p><p dir="ltr">Study III: Combining SEMG with isometric abdominal strength testing provides reliable and valid assessment of muscle function in ARD patients. A considerable improvement on standard strength tests.</p><p dir="ltr">Study IV: The 5-STS test, particularly the standard 43 cm chair height version, is a reliable, valid, and feasible tool for assessing functional performance in women with ARD, capturing functional impairments more effectively than traditional strength tests.</p><h3>List of scientific papers</h3><p dir="ltr">I. <b>Swedenhammar E,</b> Stark B, Hållstrand AH, Ehrström M, Gahm J. Surgical Training and Standardised Management Guidelines Improved the 30-Day Complication Rate After Abdominoplasty for Massive Weight Loss. World J Surg. 2018; 42(6): 1647-1654.<br><a href="https://doi.org/10.1007/s00268-017-4341-8">https://doi.org/10.1007/s00268-017-4341-8</a><br></p><p dir="ltr"><br></p><p dir="ltr">II. <b>Swedenhammar E,</b> Strigård K, Emanuelsson P, Gunnarsson U, Stark B. Long-term follow-up after surgical repair of abdominal rectus diastasis: a prospective randomised study. Scand J Surg. 2021 Sep;110(3):283-289.<br><a href="https://doi.org/10.1177/1457496920913677">https://doi.org/10.1177/1457496920913677</a><br></p><p dir="ltr"><br></p><p dir="ltr">III. <b>Swedenhammar E,</b> Wahlström O, de Brandt J, Strigård K, Häger C, Stark B, Nyberg A. Reliability and validity of surface EMG assessments combined with isometric muscle strength testing in patients with abdominal rectus diastasis and asymptomatic controls. Hernia. 2024 Jun 8.<br><a href="https://doi.org/10.1007/s10029-024-03076-y" rel="noreferrer" target="_blank">https://doi.org/10.1007/s10029-024-03076-y</a><br></p><p dir="ltr"><br></p><p dir="ltr">IV. Wahlström O, <b>Swedenhammar E,</b> Strigård K, Stark B, Nyberg A. Test-retest reliability, convergent validity and feasibility of five- time sit-to-stand tests in women with and without diastasis recti abdominis. [Submitted]</p>