Limitations of Electromyography in the Assessment of Abdominal Wall Muscle Contractility Following Botulinum Toxin A Injection

Purpose: Pre-operative botulinum toxin A (BTA) injection of the lateral obliques aims to facilitate the closure of large ventral hernia defects and decrease the risk of repair breakdown during the critical healing phase. The exact duration of post-operative BTA effect and top-up timing in cases at high risk of recurrence remains uncertain. This study was designed to assess the value of electromyography (EMG) in determining the appropriate time for BTA top-up.Methods: 56 patients underwent ventral hernia repair with pre-operative BTA infiltration of the lateral obliques. Eleven patients at high risk of recurrence considered suitable for BTA top-up were assessed post-operatively with both functional computed tomography (CT) and EMG. CT assessed segmental contractility of each muscle layer. Single-point EMG assessed the activity of individual muscle layers bilaterally in the anterior axillary line.Results: CT showed (i) variable contractility of anterior and posterior muscle segments prior to BTA injection; (ii) absent or incomplete muscle paralysis in over half of all segments; (iii) increased BTA effect on progress scans; and (iv) non-uniform pattern of change in BTA effect between the anterior and posterior muscle. EMG demonstrated modest voluntary activity in most muscle layers. Compared to standard of reference (CT), EMG showed moderate sensitivity (0.62), poor specificity (0.48), poor accuracy (0.57), and incorrect grading in 71% of true positive results.Conclusions: As BTA effect wanes, single-point EMG cannot reliably determine functional muscle status. A novel finding is that BTA-induced paralysis of the abdominal muscles may be remarkably non-uniform in degree, distribution and duration

Neuromuscular and vascular hamartoma as an unusual cause of small bowel obstruction

Introduction: Neuromuscular and vascular hamartoma (NMVH) is a rare, controversial lesion of the intestine, with only 23 cases reported in the English literature since its initial description in 1982. Presentation of case: A 59 year old female suffering from longstanding Crohn’s disease with chronic stricture presented with symptoms of small bowel obstruction. Contrast studies demonstrated massive dilatation of the proximal small bowel. Laparotomy identified a 5 cm long stenotic segment of ileum, with grossly distended jejunum and ileum proximally. Pathology determined the stricture’s aetiology as a neuromuscular and vascular hamartoma of the small intestine. Discussion: NMVH is a benign lesion of hamartomatous origin. Its very existence is questionable due to histological similarities with several reactive pathologies, such as Crohn’s and diaphragm diseases. Conclusion: NMVH could be confused with a spectrum of chronic inflammatory bowel conditions, but this report establishes it as a distinct cause of chronic bowel obstruction

Minimally invasive Venetian blinds ventral hernia repair with botulinum toxin chemical component separation

Background: Laparoscopic ventral repair is safe, with lower wound infection rates compared with open repair. ‘Venetian blinds’ technique of plication in combination with mesh reinforcement, is totally intra‐corporeal, with hernia defect and sac plication to reduce seroma formation. While laparoscopic suturing of the abdominal wall can represent a technical challenge, pre‐operative botulinum toxin A (BTA) injections as an adjunct can assist. This study aims to demonstrate feasibility and efficacy of this technique in abdominal wall hernia repair, with BTA adjunct in midline hernias. Methods: A single‐centre case series was conducted using minimally invasive ‘Venetian blinds’ technique for repair of complex ventral abdominal hernias. Twelve patients (seven midline, five non‐midline) underwent repair (11 laparoscopic; one robotic). Midline hernias received BTA (200–300 units Botox) 4–6 weeks prior to surgery. Repairs were mesh‐reinforced following fascial closure. Results: Twelve (10 female, two male) patients, with a median age 72 years (range 31–83) and body mass index of 27.3 kg/m2 (range 22.8–61.7) were included. The median length of operation was 133 min (range 45–290) and length of hospital stay 3 days (range 1–28). To date there has been no recurrence of hernia. A single symptomatic seroma was treated with antibiotics and did not require mesh removal. One patient developed hospital‐acquired pneumonia and pseudomembranous colitis. Conclusion: Minimally invasive ‘Venetian blinds’ technique has promising early results with both midline and non‐midline ventral hernias. The addition of BTA is a novel and feasible combination for repair of midline ventral hernias

Preoperative chemical component relaxation using Botulinum toxin A : enabling laparoscopic repair of complex ventral hernia

Background: Repair of complex ventral hernia can be very challenging for surgeons. Closure of large defects can have serious pathophysiological consequences. Botulinum toxin A (BTA) has recently been described to provide flaccid paralysis to abdominal muscles prior to surgery, facilitating closure and repair. Methods: This was a prospective observational study of 32 patients who underwent ultrasound-guided injections of BTA to the lateral abdominal wall muscles prior to elective repair of complex ventral hernia between January 2013 and December 2015. Serial non-contrast abdominal CT imaging was performed to measure changes in fascial defect size, abdominal wall muscle length and thickness. All hernias were repaired laparoscopically or laparoscopic-assisted with placement of intra-peritoneal mesh. Results: Thirty-two patients received BTA injections which were well tolerated with no complications. A comparison of baseline (preBTA) CT imaging with postBTA imaging demonstrated an increase in mean baseline abdominal wall length from 16.4 to 20.4 cm per side (p < 0.0001), which translates to a gain in mean transverse length of the unstretched anterolateral abdominal wall muscles of 4.0 cm/side (range 0–11.7 cm/side). Fascial closure was achieved in all cases, with no instances of raised intra-abdominal pressures or its sequelae, and there have been no hernia recurrences to date. Conclusions: Preoperative BTA injection to the muscles of the anterolateral abdominal wall is a safe and effective technique for the preoperative preparation of patients prior to laparoscopic mesh repair of complex ventral hernia. This technique elongates and thins the contracted and retracted musculature, enabling closure of large defects

Laparoscopic repair of complex ventral hernia facilitated by pre-operative chemical component relaxation using Botulinum Toxin A

Purpose: The operative management of complex ventral hernia poses a formidable challenge, despite recent advances in surgical techniques. Recurrence rates after complex ventral hernia repair remain high, and increase with each failed attempt. This study examines the effect of pre-operative abdominal wall chemical component relaxation using Botulinum Toxin A (BTA) to induce temporary flaccid paralysis in order to facilitate laparoscopic repair of large complex ventral hernia. Methods: This is a prospective evaluation of 27 patients from January 2013 to August 2015 who underwent ultrasound guided BTA injections to the lateral abdominal wall muscles prior to elective complex ventral hernia repair. Non-contrast serial CT imaging was obtained pre- and post-BTA injection to measure change in fascial defect size and abdominal wall muscle thickness and length. Fascial defects were closed and hernias repaired using laparoscopic or laparoscopic-assisted intra-peritoneal onlay mesh (IPOM) techniques. Results: 27 patients received pre-operative BTA injections which were well tolerated with no complications. Comparison of pre-BTA and post-BTA CT imaging demonstrated a significant increase in mean length of the lateral abdominal wall from 15.7 cm pre-BTA to 19.9 cm post-BTA (p < 0.0001), with mean unstretched length gain of 4.2 cm/side (range 0–11.7 cm/side). All hernias were surgically reduced and repaired with mesh, with no early recurrences. Conclusion: Pre-operative administration of BTA is a safe and effective technique in the pre-operative preparation of patients undergoing elective complex ventral hernia repair. This technique lengthens and relaxes the laterally retracted abdominal muscles and enables laparoscopic closure of large complex ventral hernia