Imaging Insights Into Abdominal Wall Function.

Purpose: The successful repair of any complex ventral hernia requires a thorough understanding of the underlying anatomical defect and its functional context. We describe an improved "functional" approach to CT imaging of the abdominal wall that can facilitate this understanding and assist surgical planning. Methods: This invited article reports the observational experience gained from the functional abdominal wall CT examinations of 88 patients who underwent complex ventral hernia repair using pre-operative Botulinum toxin A (BTA) infiltration of the lateral oblique abdominal muscles as well as a further eight patients with diastasis rectus abdominis who were examined to exclude ventral hernia. Results: The use of a functional CT protocol which supplements resting images with additional "crunching" images (acquired with the abdominal wall muscles all strongly contracted) can significantly improve the demonstration of ventral hernia defects. Crunching acquisitions can also help differentiate true hernias from dysfunctional bulges, identify muscle denervation or atrophic changes, reveal otherwise occult hernias that may be missed on resting or Valsalva images alone, and assist the pre-operative assessment of BTA effect. Conclusion: A more functional approach to pre-operative CT imaging of the abdominal wall can significantly improve the understanding of complex ventral hernia defects and help formulate effective surgical plans that achieve low recurrence rates and good functional outcomes.

Preoperative Progressive Pneumoperitoneum Revisited.

Incisional hernia represents a common and potentially serious complication of open abdominal surgery, with up to 20% of all patients undergoing laparotomy subsequently developing an incisional hernia. This incidence increases to as much as 35% for laparotomies performed in high-risk patients and emergency procedures. A rarely used technique for enabling closure of large ventral hernias with loss of domain is preoperative progressive pneumoperitoneum (PPP), which uses intermittent insufflation to gradually stretch the contracted abdominal wall muscles, increasing the capacity of the abdominal cavity and allowing viscera to re-establish right of domain. This assists in tension-free closure of giant hernias which may otherwise be considered inoperable. This technique may be used on its own, or in conjunction with preoperative Botulinum Toxin A to confer paralysis to the lateral oblique muscles. These two complementary techniques, are changing the way complex hernias are managed.

Fascial closure in giant ventral hernias after preoperative botulinum toxin a and progressive pneumoperitoneum: A systematic review and meta-analysis.

BACKGROUND: The primary objective was to assess the perioperative efficacy of the preoperative use of progressive pneumoperitoneum or Botulinum Toxin A injections in ventral hernia repair. METHODS: Embase, Medline Ovid, Web of Science, Cochrane Central, and Google Scholar were systematically searched. Studies in English reporting on fascial closure, indications, complications or postoperative outcomes in adult patients that had undergone progressive pneumoperitoneum, Botulinum Toxin A injections, or both before ventral hernia repair were included. Study quality was assessed with the Oxford Levels of Evidence guidelines and the Methodological Index for Non-Randomized Studies criteria. A pooled fascial closure rate and recurrence rate were calculated with random effects models. RESULTS: Twenty studies were included from the 905 identified, comprising the use progressive pneumoperitoneum (n = 11), Botulinum Toxin A (n = 6), and both techniques (n = 3). The overall fascial closure rate was 0.94 (95% confidence interval 0.89-0.98). Indications for the use of progressive pneumoperitoneum or Botulinum Toxin A were based on objective (eg, computed tomography measurements) or subjective measures (eg, foreseen surgical problems). In contrast to the use of Botulinum Toxin A, reported complications with the use of progressive pneumoperitoneum were ample and sometimes severe. The cumulative reported recurrence rate was 0.03 (95% confidence interval 0.01-0.06). CONCLUSION: Preoperative progressive pneumoperitoneum and Botulinum Toxin A can facilitate fascial closure without causing significant numbers of adverse events. Botulinum Toxin A qualifies for low-threshold use, yet progressive pneumoperitoneum should be used cautiously owing to a larger number of complications. Definitive recommendations cannot be made as the quality of included studies is low, bias is present, and comparative information is scarce. Registration number Information about the design and conduct of this systematic review has been registered on PROSPERO, registration number CRD42020181679.

Functional 3DVR imaging of abdominal wall hernias.

The purpose of this illustrative pictorial series is to demonstrate the value of an image technique known as 3D Volume Rendering (3DVR) for the pre-operative visualization and assessment of complex abdominal hernias. A small subset of complex abdominal hernia cases were selected from our early clinical experience with 3DVR to illustrate the value of visualizing standard 2D computed tomography (CT) data from a 3D perspective. For the surgeon, pre-operative 3DVR can assist the holistic understanding of abdominal hernias and any associated fascial defects, unsuspected additional hernias, dysfunctional abdominal wall bulges/eventrations, muscle denervations or atrophic changes, mesh placements, other post-surgical changes such as scarring, and relevant skeletal changes. For the patient, 3DVR provides an easily grasped understanding of the relevant anatomy, the nature of the problem at hand, and the scale of the surgical challenge. Images of this kind can help the surgeon to more effectively manage unrealistic patient expectations or explain dysfunctional bulges that do not require surgery. A functional 3DVR approach to pre-operative imaging can provide the surgeon with a more complete understanding of any hernia defect and the relevant background status of the abdominal wall in general. This can be useful in planning a more effective operative approach and help to improve surgical outcomes.

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.

Definitions for Loss of Domain: An International Delphi Consensus of Expert Surgeons.

BACKGROUND: No standardized written or volumetric definition exists for 'loss of domain' (LOD). This limits the utility of LOD as a morphological descriptor and as a predictor of peri- and postoperative outcomes. Consequently, our aim was to establish definitions for LOD via consensus of expert abdominal wall surgeons. METHODS: A Delphi study involving 20 internationally recognized abdominal wall reconstruction (AWR) surgeons was performed. Four written and two volumetric definitions of LOD were identified via systematic review. Panelists completed a questionnaire that suggested these definitions as standardized definitions of LOD. Consensus on a preferred term was pre-defined as achieved when selected by ≥80% of panelists. Terms scoring <20% were removed. RESULTS: Voting commenced August 2018 and was completed in January 2019. Written definition: During Round 1, two definitions were removed and seven new definitions were suggested, leaving nine definitions for consideration. For Round 2, panelists were asked to select all appealing definitions. Thereafter, common concepts were identified during analysis, from which the facilitators advanced a new written definition. This received 100% agreement in Round 3. Volumetric definition: Initially, panelists were evenly split, but consensus for the Sabbagh method was achieved. Panelists could not reach consensus regarding a threshold LOD value that would preclude surgery. CONCLUSIONS: Consensus for written and volumetric definitions of LOD was achieved from 20 internationally recognized AWR surgeons. Adoption of these definitions will help standardize the use of LOD for both clinical and academic activities.

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.

ClosureFast endovenous radiofrequency ablation for great saphenous vein and small saphenous vein incompetence: Efficacy and anatomical failure patterns.

BACKGROUND: Recurrence rates and patterns after endovenous radiofrequency ablation (ERFA) are poorly documented. OBJECTIVE: To assess the incidence and anatomical recurrence patterns of saphenous vein reflux after ERFA. METHOD: Two hundred patients previously treated with ERFA were recalled for clinical assessment and venous-duplex ultrasound at three years post-treatment. RESULTS: A total of 106 patients (68F, 38M) with a mean age of 49.4 years (SD +11.5y) were assessed. Mean follow-up was 42.1 months (SD + 20.1m). Further varicose veins were identified in 31 patients (29.2%). Recanalization/recurrence/failure was diagnosed in 16 patients (15.1%), including 18 trunks (8.7%), 13 great saphenous vein (6.3%) and 5 small saphenous vein (2.4%). Twenty-seven patients (25%) developed neo-incompetence in 31 trunks and 12 non-saphenous veins. All patients with truncal recanalization had a body mass index > 29 (range 29-42). CONCLUSION: Disease progression was twice as high as the recanalization rate at three years post-treatment using ERFA in this study. Raised body mass index may be a contributing factor; however, further longitudinal studies are required. Patient self-selection bias may have also influenced our results.

Preoperative Botulinum toxin A enabling defect closure and laparoscopic repair of complex ventral hernia.

INTRODUCTION: Operative management of complex ventral hernia still remains a significant challenge for surgeons. Closure of large defects in the unprepared abdomen has serious pathophysiological consequences due to chronic contraction and retraction of the lateral abdominal wall muscles. We report outcomes of 56 consecutive patients who had preoperative Botulinum toxin A (BTA) abdominal wall relaxation facilitating closure and repair. METHODS: This was a prospective observational study of 56 patients who underwent ultrasound-guided BTA into the lateral abdominal oblique muscles prior to elective ventral hernia repair between November 2012 and January 2017. Serial non-contrast abdominal CT imaging was performed to evaluate changes in lateral oblique muscle length and thickness. All hernias were repaired laparoscopically, or laparoscopic-open-laparoscopic (LOL) using intraperitoneal onlay mesh. RESULTS: 56 patients received BTA injections at predetermined sites to the lateral oblique muscles, which were well tolerated. Mean patient age was 59.7 years, and mean BMI was 30.9 kg/m2 (range 21.8-54.0). Maximum defect size was 24 × 27 cm. A subset of 18 patients underwent preoperative pneumoperitoneum as an adjunct procedure. A comparison of pre-BTA to post-BTA imaging demonstrated an increase in mean lateral abdominal wall length from 16.1 cm to 20.1 cm per side, a mean gain of 4.0 cm/side (range 1.0-11.7 cm/side) (p < 0.0001). This corresponds to an unstretched mean length gain of 8.0 cm of the lateral abdominal wall. Laparoscopic/LOL primary closure was achieved in all cases, with no clinical evidence of raised intra-abdominal pressures. One patient presented with a new fascial defect 26 months post-operative. CONCLUSION: Preoperative BTA to the lateral abdominal wall muscles is a safe and effective technique for the preparation of patients prior to operative management of complex ventral hernias. BTA temporary flaccid paralysis relaxes, elongates and thins the chronically contracted abdominal musculature. This in turn reduces lateral traction forces facilitating laparoscopic repair and fascial closure of large defects under minimal tension.

Single port component separation: endoscopic external oblique release for complex ventral hernia repair.

BACKGROUND: Component separation (CS) is a technique which mobilizes flaps of innervated, vascularized tissue, enabling closure of large ventral hernia defects using autologous tissue. Disadvantages include extensive tissue dissection when creating these myofascial advancement flaps, with potential consequences of significant post-operative skin and wound complications. This study examines the benefit of a novel, ultra-minimally invasive single port anterior CS technique. METHODS: This was a prospective study of 16 external oblique (EO) releases performed in 9 patients and 4 releases performed in 3 fresh frozen cadavers. All patients presented with recurrent complex ventral hernias, and were administered preoperative Botulinum Toxin A to their lateral oblique muscles to facilitate defect closure. At the time of elective laparoscopic repair, patients underwent single port endoscopic EO release using a single 20-mm incision on each side of the abdomen. Measurements were taken using real-time ultrasound. Postoperatively, patients underwent serial examination and abdominal CT assessment. RESULTS: Single port endoscopic EO release achieved a maximum of 50-mm myofascial advancement per side (measured at the umbilicus). No complications involving wound infection, hematoma, or laxity/bulge have been noted. All patients proceeded to laparoscopic or laparoscopic-open-laparoscopic intraperitoneal mesh repair of their hernia, with no hernia recurrences to date. CONCLUSIONS: Single port endoscopic EO release holds potential as an adjunct in the repair of large ventral hernia defects. It is easy to perform, is safe and efficient, and entails minimal disruption of tissue planes and preserves abdominal wall perforating vessels. It requires only one port-sized incision on each side of the abdomen, thus minimizing potential for complications. Further detailed quantification of advancement gains and morbidity from this technique is warranted, both with and without prior administration of Botulinum Toxin A to facilitate closure.

The sural nerve: Sonographic anatomy, variability and relation to the small saphenous vein in the setting of endovenous thermal ablation.

Background Neurological complications are well documented in association with both surgical stripping or disconnection and thermal ablation of the small saphenous vein. The sural nerve (medial sural cutaneous nerve) is most vulnerable due to its close relationship to the small saphenous vein. Objective This is a cross-sectional observational study of the sonographic anatomy of 115 Australian patients to determine the course of the sural nerve and its relationship to the small saphenous vein, and to identify its relevance in the thermal ablation of the small saphenous vein. Method Sonographic mapping of the right sural nerve was performed with a Philips L12.5 and Sonosite 10.5 MHz ultrasound machine on 115 patients. The sural nerve was traced proximally from the level of the lateral malleolus to the popliteal fossa in order to measure its distance from the small saphenous vein at four reference points in the lower leg. Results A total of 115 patients were studied (females 82, males 33). The sural nerve was identified in 100% of patients; 64 patients (55.7%) showed usual sural nerve anatomy, while 51 patients (44.3%) demonstrated a range of anatomical variations, including the sural nerve becoming epifascial at a higher point than usual. Conclusion The sural nerve was identifiable on duplex ultrasound in 100% of cases. Classic anatomical relations and the perceived protection of the sural nerve conferred by the deep fascia of the upper calf are unreliable. Preoperative strategies can help to approach and protect the sural nerve in the endovenous ablation setting.

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.

Preoperative progressive pneumoperitoneum complementing chemical component relaxation in complex ventral hernia repair.

BACKGROUND: A rarely used technique for enabling closure of large ventral hernias with loss of domain is preoperative progressive pneumoperitoneum (PPP), which uses intermittent insufflation to gradually stretch the contracted abdominal wall muscles, increasing the capacity of the abdominal cavity. This allows the re-introduction of herniated viscera into the abdominal cavity and assists in closure of giant hernias which may otherwise be considered inoperable. METHODS: This was a prospective study assessing 16 patients between 2013 and 2015 with multi-recurrent ventral hernia. All patients were treated preoperatively with both Botulinum Toxin A (BTA) injections to the lateral abdominal wall muscles to confer flaccid paralysis, and short-term PPP to passively expand the abdominal cavity. All patients underwent serial abdominal CT imaging, with pre- and post-treatment circumference measurements of the peritoneal cavity and hernia sac, prior to undergoing operative mesh repair of their hernia. RESULTS: The mean hernia defect size was 236 cm2, with mean 28 % loss of domain. The mean overall duration of PPP was 6.2 days. The mean gain in abdominal circumference was 4.9 cm (5.6 %) (p 0.002) after BTA and PPP. Fascial closure and mesh hernia repair were performed in all 16 patients, with no patients suffering from postoperative abdominal hypertension, ventilatory impairment, or wound dehiscence. There are no hernia recurrences to date. Eight patients (50 %) experienced PPP-related complications, consisting of subcutaneous emphysema, pneumothorax, pneumomediastinum, pneumocardium, and metabolic acidosis. No complication required intervention. CONCLUSIONS: PPP is a useful adjunct in the repair of complex ventral hernia. It passively expands the abdominal cavity, allowing viscera to re-establish right of domain. At the same time, it helps to minimize the risks of postoperative abdominal compartment syndrome and the sequelae of fascial closure under tension. However, its benefits must be carefully weighed with the risk of serious complications, such as infection, perforation, pneumothorax, and pneumomediastinum.

Hydrodisplacement of sural nerve for safety and efficacy of endovenous thermal ablation for small saphenous vein incompetence.

Background Endovenous radio frequency ablation for small saphenous vein incompetence by and large appears to be superior and safer than conventional open surgery. Small saphenous vein ablation from approximately mid-calf to the point proximally where the small saphenous vein dives into the popliteal fossa is considered to be safe, as the sural nerve is in most cases separated from this segment of the small saphenous vein by the deep fascia. The outcome of the distal incompetent small saphenous vein remains unclear. Efficacy of the endovenous radio frequency ablation can be enhanced by increasing the length of the ablatable small saphenous vein segment. Methodology To optimise endovenous radio frequency ablation outcome, the distal small saphenous vein may be made amenable to ablation if safety of the sural nerve can be assured. The sural nerve was successfully located using duplex ultrasound in 100% of our cohort in this study. The standard entry point for venous access was just above the lateral malleolus. After introduction of the introducer sheath, the radio frequency catheter was advanced proximally; the sural nerve was displaced from the small saphenous vein by approximately 1 cm with the administration of tumescent anaesthesia ( hydrodisplacement). A total of 118 patients underwent extended endovenous radio frequency ablation of 124 incompetent small saphenous vein trunks using the method described. Results Successful extended ablation of the small saphenous vein was achieved in 100% of cases and it was confirmed by duplex scanning at one and six weeks. Two neurological events were recorded during the study: 1. One patient with temporary foot drop lasting for less than 6 h with complete recovery. 2. A second patient with a sural nerve sensory deficit reported by the patient at day 2-3, which remains current at six weeks. Conclusions Extended endovenous radio frequency ablation of the small saphenous vein to optimise length of the ablatable vein segment is feasible with careful identification and hydrodisplacement of the sural nerve. This method is shown to be associated with fewer neurological complications than other methods reported in the literature.

Preoperative abdominal muscle elongation with botulinum toxin A for complex incisional ventral hernia repair.

BACKGROUND: Surgical repair of recurrent abdominal incisional hernia(s) can be challenging due to complex operative conditions, intense post-operative pain, potential respiratory compromise and lateral muscle traction predisposing to early recurrence. We report our preliminary results with botulinum toxin A (BTA) injection causing flaccid paralysis (relaxation) of the lateral abdominal wall muscles prior to surgery. METHODS: A prospective pilot study measured the effect of preoperative BTA prior to elective repair of recurrent abdominal hernias. Under ultrasound control, 2 weeks prior to surgery, 50 units of BTA was injected into the external oblique, internal oblique and transversus abdominis muscles at three sites on each side of the lateral abdominal wall (total dose 300 units). Pre- and post-BTA abdominal computed tomography measured changes in abdominal wall muscle thickness and length. All hernias were repaired with laparoscopic or laparoscopic-assisted mesh techniques in a single or two-staged procedure. RESULTS: Eight patients received BTA injections which were tolerated with no complications. Post-BTA preoperative computed tomography showed a significant increase in mean length of lateral abdominal wall from 18.5 cm pre-BTA to 21.3 cm post-BTA (P = 0.017) with a mean unstretched length gain of 2.8 cm per side (range 0.8-6.0 cm). All hernias were surgically reduced with mesh with no early recurrence. CONCLUSION: Preoperative BTA injection prior to complex abdominal hernia repair is a safe procedure that causes flaccid relaxation, elongation and thinning of the lateral abdominal muscles and decrease in hernia defect. Although further evaluation is required, BTA injections may be a useful adjunct to surgical repair of complex incisional hernias.