Chemical Components Separation: Concepts, Evidence, and Outcomes

Abdominal Wall Tension and Early Outcomes after Posterior Component Separation with Transversus Abdominis Release: Does a "Tension-Free" Closure Really Matter?

BACKGROUND

Ventral hernias result in fibrosis of the lateral abdominal wall muscles, increasing tension on fascial closure. Little is known about the effect of abdominal wall tension on outcomes after abdominal wall reconstruction. We aimed to identify an association between abdominal wall tension and early postoperative outcomes in patients who underwent posterior component separation (PCS) with transversus abdominis release (TAR).

STUDY DESIGN

Using a proprietary, sterilizable tensiometer, the tension needed to bring the anterior fascial elements to the midline of the abdominal wall during PCS with TAR was recorded. Tensiometer measurements, in pounds (lb), were calibrated by accounting for the acceleration of Earth's gravity. Baseline fascial tension, change in fascial tension, and fascial tension at closure were evaluated with respect to 30-day outcomes, including wound morbidity, hospital readmission, reoperation, ileus, bleeding, and pulmonary complications.

RESULTS

A total of 100 patients underwent bilateral abdominal wall tensiometry, for a total of 200 measurements (left and right side for each patient). Mean baseline anterior fascial tension was 6.78 lb (SD 4.55) on each side. At abdominal closure, the mean anterior fascial tension was 3.12 (SD 3.21) lb on each side. Baseline fascial tension and fascial tension after PCS with TAR at abdominal closure were not associated with surgical site infection, surgical site occurrence, readmission, ileus, and bleeding requiring transfusion. The event rates for all other complications were too infrequent for statistical analysis.

CONCLUSIONS

Baseline and residual fascial tension of the anterior abdominal wall do not correlate with early postoperative morbidity in patients undergoing PCS with TAR. Further work is needed to determine if abdominal wall tension in this context is associated with long-term outcomes, such as hernia recurrence.

Use of botulinum toxin type A in the prehabilitation of abdominal wall musculature for hernia repair: a consensus proposal

The prehabilitation of the abdominal wall through the infiltration of botulinum toxin type A, which induces temporary chemical denervation ("chemical component separation") in the lateral abdominal musculature, is a common practice in units specialized in abdominal wall surgery. However, its use for this indication is currently off-label. The main objective of this article is to describe a consensus proposal regarding indications, contraindications, dosages employed, potential side effects, administration method, and measurement of possible outcomes. Additionally, a proposal for an informed consent document endorsed by the Abdominal Wall Section of the Spanish Association of Surgeons is attached.

Surgical Anatomy of Transversus Abdominis Muscle for Transversus Abdominis Release: A CT-Based Study in Three Patient Groups

BACKGROUND

The anatomy of the transversus abdominis muscle and its aponeurosis is important in transversus abdominis release surgery. We studied the CT anatomy of the transversus abdominis muscle medial to the linea semilunaris at different levels in the abdomen and measured the thickness of this muscle.

METHODS

In this retrospective study, we analysed 150 abdominal computed tomography at L1, L3, and L5 vertebral levels corresponding to subxiphoid, umbilical, and suprapubic regions, respectively. The patients were divided into three groups based on age and sex: women aged 15-20 years (nulliparous), women aged 30-60 years (multiparous), and men aged 15-60 years, with each group having 50 patients. We compared the thickness of the TA muscle at the L1 level between men and women and between nulliparous and multiparous women.

RESULTS

Transversus abdominis muscle was consistently present medial to the linea semilunaris at L1 vertebral level in the subxiphoid region (150/150). At the L3 vertebral level in the mid-abdomen, only eight patients had the transversus abdominis muscle there (8/150, 5%). At the L5 vertebral level in the suprapubic region, no patient had the transversus abdominis muscle medial to the linea semilunaris. The mean thickness of the transversus abdominis muscle at the L1 level was 3.4 mm, and at the L3 level, it was 1.6 mm. There was no statistically significant difference in the transversus abdominis muscle thickness between the men and women; however, a significant difference was found between the nulliparous and multiparous women, with thinner TA muscle in later.

CONCLUSION

There is good transversus abdominis muscle bulk medial to the linea semilunaris for doing transversus abdominis muscle division in the upper abdomen. However, as we move towards the mid-abdomen, we have TA aponeurosis or rarely TA muscle of little bulk.

Successful Administration of Preoperative Botox for Giant Omphalocele Repair With Ultrasound Guidance

We present a case of a four-year-old male with a history of giant omphalocele who underwent ultrasound-guided Botox injection to bilateral anterior abdominal wall musculature in preparation for definitive repair. Botox administration was successfully combined with preoperative subfascial tissue expanders to achieve definitive midline closure of the anterior abdominal wall defect. Our experience suggests that Botox can be safely used as part of the treatment plan for giant omphalocele repair.

Preoperative botulinum toxin A (BTA) injection versus component separation techniques (CST) in complex abdominal wall reconstruction (AWR): A propensity-scored matched study

BACKGROUND

Complete fascial closure significantly reduces recurrence rates and wound complications in abdominal wall reconstruction. While component separation techniques have clear effectiveness in closing large abdominal wall defects, preoperative botulinum toxin A has emerged as an adjunct to aid in fascial closure. Few data exist comparing preoperative botulinum toxin A to component separation techniques, and the aim was to do so in a matched study.

METHODS

A prospective, single-center, hernia-specific database was queried, and a 3:1 propensity-matched study of patients undergoing open abdominal wall reconstruction from 2016 to 2021 with botulinum toxin A versus component separation techniques was performed based on body mass index, defect width, hernia volume, and Centers for Disease Control and Prevention wound classification. Demographics, operative characteristics, and outcomes were evaluated.

RESULTS

Matched patients included 105 component separation techniques and 35 botulinum toxin A. There was no difference in tobacco use, diabetes, or body mass index (all P > .5). Hernia defects and volume were large for both the component separation techniques and botulinum toxin A groups (mean size: component separation techniques 286.2 ± 179.9 cm² vs botulinum toxin A 289.7 ± 162.4 cm²; P = .73) (mean volume: 1,498.3 + 2,043.4 cm³ vs 2,914.7 + 6,539.4 cm³; P = .35). Centers for Disease Control and Prevention wound classifications were equivalent (CDC3 and 4%-39.1% vs 40.0%; P = .97). Component separation techniques were more frequently performed in European Hernia Society M1 hernias (21% vs 2.9%; P = .01). The botulinum toxin A group had fewer surgical site occurrences (32.4% vs 11.4%; P = .02) and surgical site infections (11.7% vs 0%; P = .04). In multivariate analysis, botulinum toxin A was associated with lower rates of surgical site occurrences (odds ratio = 5.3; 95% confidence interval [1.4-34.4]). There was no difference in fascial closure (90.5% vs 100%; P = .11) or recurrence (12.4% vs 2.9%; P = .10) with follow-up (22.8 + 29.7 vs 9.8 + 12.7 months; P = .13).

CONCLUSION

In a matched study comparing patients with botulinum toxin A versus component separation techniques, there was no difference in fascial closure rates or in hernia recurrence between the 2 groups. Preoperative botulinum toxin A can achieve similar outcomes as component separation techniques, while decreasing the frequency of surgical site occurrences.

State-of-the-art abdominal wall reconstruction and closure

Open ventral hernia repair is one of the most common operations performed by general surgeons. Appropriate patient selection and preoperative optimization are important to ensure high-quality outcomes and prevent hernia recurrence. Preoperative adjuncts such as the injection of botulinum toxin and progressive preoperative pneumoperitoneum are proven to help achieve fascial closure in patients with hernia defects and/or loss of domain. Operatively, component separation techniques are performed on complex hernias in order to medialize the rectus fascia and achieve a tension-free closure. Other important principles of hernia repair include complete reduction of the hernia sac, wide mesh overlap, and techniques to control seroma and other wound complications. In the setting of contamination, a delayed primary closure of the skin and subcutaneous tissues should be considered to minimize the chance of postoperative wound complications. Ultimately, the aim for hernia surgeons is to mitigate complications and provide a durable repair while improving patient quality of life.

Immediate changes in intra-abdominal pressure and lung indicators in patients undergoing complex ventral hernia repair with the transversus abdominis muscle release, with and without preoperative botulinum toxin

PURPOSE

The current treatment of complex ventral hernias involves muscle closure with components separation techniques and mesh placement. The purpose of this study is to evaluate the immediate postoperative changes in the intra-abdominal pressure (IAP), and lung indicators after treatment of complex ventral hernias with the transversus abdominis reléase (TAR) technique.

METHODS

All patients with complex ventral hernias treated between November 28th, 2016 and October 6th, 2021 were initially included. We excluded patients with lung and/or heart comorbidities. A total of 43 patients were studied, measuring IAP, lung compliance, pulmonary plateau pressure (PPP), and end-tidal CO₂ before and after surgical treatment.

RESULTS

Median IAP increased from 5 to 9 mmHg (p < 0.0001), and PPP from 11 to 12 mmHg (p = 0.004). Increased body mass index (BMI) was associated to a PPP increase above normal values. Postoperative changes were not different in patients receiving preoperative preparation with botulinum toxin.

CONCLUSION

After complex ventral hernia closure, there is an immediate impact on IAP and PPP, the latter more frequent in patients with the highest BMI, and this may not be prevented by the preoperative administration of botulinum toxin.

Preoperative botulinum A toxin as an adjunct for abdominal wall reconstruction: a single-center early experience at an Academic Center in New York

INTRODUCTION

the botulinum toxin A (BTA) has been used to achieve a chemical component separation, and it has been used with favorable outcomes for the repair of complex ventral hernia (CVH) with and without loss of domain (LD). The aim of this study is to describe our early experience with the chemical component separation in the United Sates.

METHODS

a retrospective observational study of all patients who underwent ventral hernia repair for CVH with or without LD between July 2018 and June 2020. Preoperative BTA was injected in all patients via sonographic guidance bilaterally, between the lateral muscles to achieve chemical denervation before the operation. Patient demographics, anatomical location of the hernia, perioperative data and postoperative data are described.

RESULTS

36 patients underwent this technique before their hernia repair between July 2018 to June 2020. Median age was 62 years (range 30-87). Median preoperative defect size was 12cm (range 6-25) and median intraoperative defect size was 13cm (range 5-27). Median preoperative hernia sac volume (HSV) was 1338cc (128-14040), median preoperative abdominal cavity volume (ACV) was 8784cc (5197-18289) and median volume ration (HSV/ACV) was 14%. The median OR time for BTA administration was 45 minutes (range 28-495). Seroma was the most common postoperative complication in 8 of the patients (22%). Median follow up was 43 days (range 0-580).

CONCLUSION

preoperative chemical component separation with BTA is a safe and effective adjunct to hernia repair in CVH repairs where a challenging midline fascial approximation is anticipated.

Factors Predicting Increased Length of Stay in Abdominal Wall Reconstruction

BACKGROUND

Enhanced recovery after surgery (ERAS) programs have become increasingly popular in general surgery, yet no guidelines exist for an abdominal wall reconstruction (AWR)-specific program. We aimed to evaluate predictors of increased length of stay (LOS) in the AWR population to aid in creating an AWR-specific ERAS protocol.

METHODS

A prospective, single institution hernia center database was queried for all patients undergoing open AWR (1999-2019). Standard statistical methods and linear and logistic regression were used to evaluate for predictors of increased LOS. Groups were compared based on LOS below or above the median LOS of 6 days (IQR = 4-8).

RESULTS

Inclusion criteria were met by 2,505 patients. On average, the high LOS group was older, with higher rates of CAD, COPD, diabetes, obesity, and pre-operative narcotic use (all P < .05). Longer LOS patients had more complex hernias with larger defects, higher rates of mesh infection/fistula, and more often required a component separation (all P < .05). Multivariate analysis identified age (β0.04,SE0.02), BMI (β0.06,SE0.03), hernia defect size (β0.003,SE0.001), active mesh infection or mesh fistula (β1.8,SE0.72), operative time (β0.02,SE0.002), and ASA score >4 (β3.6,SE1.7) as independently associated factors for increased LOS (all P < .05). Logistic regression showed that an increased length of stay trended toward an increased risk of hernia recurrence (P = .06).

CONCLUSIONS

Multiple patient and hernia characteristics are shown to significantly affect LOS, which, in turn, increases the odds of AWR failure. Weight loss, peri-operative geriatric optimization, prehabilitation of comorbidities, and operating room efficiency can enhance recovery and shorten LOS following AWR.

Effects of Botulinum Toxin A on an Incisional Hernia Reconstruction in a Rat Model

BACKGROUND

Although the effects of botulinum toxin A on hernia reconstruction have been consistently reported, few studies provide objective evidence. The authors aimed to compare the effects of chemical component separation with those of mechanical component separation, and with a combination of chemical and mechanical component separation, in a rat hernia model.

METHODS

Rats were divided into four groups: 1, control; 2, chemical component separation; 3, mechanical component separation; and 4, chemical and mechanical component separation. Four weeks after hernia induction, botulinum toxin A was injected into groups 2 and 4. Hernia repair was performed 2 weeks after chemical component separation when mechanical component separation was performed in groups 3 and 4. Pretreatment and posttreatment defect sizes, traction forces, intraabdominal pressure, and hernia recurrences were analyzed.

RESULTS

The defect size was significantly decreased in groups 2 and 4 after chemical component separation. The traction force was significantly smaller in groups 2 and 3 compared with the control group, and the effects of chemical and mechanical component separation were additive. The mean intraabdominal pressure was 16.83 mmHg in group 1, 10.67 mmHg in group 2, 10.17 mmHg in group 3, and 9.67 mmHg in group 4, thus showing significant reductions following chemical and mechanical component separation. Recurrence was observed in all six animals (100 percent) in groups 1 and 3, but in only one of six (17 percent) in groups 2 and 4.

CONCLUSIONS

Preoperative botulinum toxin A significantly reduces hernia size (by 30 percent) and the traction force required to medialize the rectus abdominis. After hernia repair, chemical component separation decreases the intraabdominal pressure to a similar degree as mechanical component separation, but only chemical component separation appears to reduce hernia recurrence.

Can Hernia Sac to Abdominal Cavity Volume Ratio Predict Fascial Closure Rate for Large Ventral Hernia? Reliability of the Tanaka Score

BACKGROUND

The hernia sac to abdominal cavity volume ratio (VR) on abdominal CT was described previously as a way to predict which hernias would be less likely to achieve fascial closure. The aim of this study was to test the reliability of the previously described cutoff ratio in predicting fascial closure in a cohort of patients with large ventral hernias.

METHODS

Patients who underwent elective, open incisional hernia repair of 18 cm or larger width at a single center were identified. The primary end point of interest was fascial closure for all patients. Secondary outcomes included operative details and abdominal wall-specific quality-of-life metrics. We used VR as a comparison variable and calculated the test characteristics (ie, sensitivity, specificity, and positive and negative predictive values).

RESULTS

A total of 438 patients were included, of which 337 (77%) had complete fascial closure and 101 (23%) had incomplete fascial closure. The VR cutoff of 25% had a sensitivity of 76% (95% CI, 71% to 80%), specificity of 64% (95% CI, 54% to 74%), positive predictive value of 88% (95% CI, 83% to 91%), and negative predictive value of 45% (95% CI, 36% to 53%). The incomplete fascial closure group had significantly lower quality of life scores at 1 year (83.3 vs 52.5; p = 0.001), 2 years (85 vs 33.3; p = 0.003), and 3 years (86.7 vs 63.3; p = 0.049).

CONCLUSIONS

In our study, the VR cutoff of 25% was sensitive for predicting complete fascial closure for patients with ratios below this threshold. Although there is a higher likelihood of incomplete fascial closure when VR is ≥ 25%, this end point cannot be predicted reliably. Additional studies should be done to study this ratio in conjunction with other hernia-related variables to better predict this important surgical end point.

Ultrasound-Guided Chemical Component Separation with Botulinum Toxin A prior to Surgical Hernia Repair

US-guided chemical component separation (CCS) of the abdominal musculature using botulinum toxin A can facilitate the surgical repair of large or complex hernias. Eight patients (2 women and 6 men with median age of 54 years [range, 34-78 years]) underwent preoperative US-guided CCS with hydrodissection before planned surgical repair of large or complex ventral (n = 4), inguinal (n = 2), and flank (n = 2) hernias by 2 interventional radiologists. Technical success rate of US-guided CCS procedures was 100%, and all patients achieved surgical closure a mean 34.1 days (range, 14-48 days) after US-guided CCS.

Prehabilitation of complex ventral hernia patients with Botulinum: a systematic review of the quantifiable effects of Botulinum

PURPOSE

Complex ventral hernia repair (CVHR) encompasses patient optimization, primary fascial closure (PFC), mesh reinforcement and component separation technique (CST), if needed. High rates of complications after CST are still reported. Prehabilitation by managing pre-operative modifiable risk factors, like abdominal wall compliance, possibly reduces these rates. Compliance can be modified by intramuscular injection of Botulinum in the lateral abdominal wall muscles (LAWM). Paralysis leads to elongation of these muscles, which may facilitate PFC and/or prevent CST. Evidence to use Botulinum in hernia patients is scarce and fragmented. An update of evidence for the effect of Botulinum is presented.

METHODS

A multi-database search was conducted for Botulinum studies in ventral hernia patients. A systematic review was performed to describe its primary effect on compliance (LAWM elongation) and secondary effects like PFC ± CST rate, complications and recurrence.

RESULTS

14 studies were included (377 patients) with a HDW of median 12 (10-15) cm. A typical intervention consisted of 200-300 U Botulinum in 3 points per hemi-abdomen under US guidance, > 2 weeks pre-operatively and evaluated by CT just before the operation. The primary effect was a median LAWM elongation of 4.0 cm per side without complications of the injection (four studies, 107 patients). The median PFC rate was 100%, CST rate 38%, wound-related complications 19%, medical complications 18% and recurrence 0% (14 studies).

CONCLUSION

Botulinum safely elongates the abdominal wall muscles, but the level of evidence available remains low. Any patient in whom PFC is expected to be difficult, could be a candidate for prehabilitation with Botulinum.

Chinese expert consensus on adult ventral abdominal wall defect repair and reconstruction

BACKGROUND

Surgical management of patients with ventral abdominal wall defects, especially complex abdominal wall defects, remains a challenging problem for abdominal wall reconstructive surgeons. Effective surgical treatment requires appropriate preoperative assessment, surgical planning, and correct operative procedure in order to improve postoperative clinical outcomes and minimize complications. Although substantial advances have been made in surgical techniques and prosthetic technologies, there is still insufficient high-level evidence favoring a specific technique. Broad variability in existing practice patterns, including clinical pre-operative evaluation, surgical techniques and surgical procedure selection, are still common.

DATA SOURCES

With the purpose of providing a best practice algorithm, a comprehensive search was conducted in Medline and PubMed. Sixty-four surgeons considered as experts on abdominal wall defect repair and reconstruction in China were solicited to develop a Chinese consensus and give recommendations to help surgeons standardize their techniques and improve clinical results.

CONCLUSIONS

This consensus serves as a starting point to provide recommendations for adult ventral abdominal wall repair and reconstruction in China and may help build opportunities for international cooperation to refine AWR practice.

Ventral hernia secondary to giant omphalocele in a child: combined approach of botulinum toxin and preoperative progressive pneumoperitoneum

Omphalocele is a congenital abdominal wall defect that occurs approximately 1 in 4000-6000 live births. The abdominal-visceral disproportion, large diameter of the defect, volume of liver in the sac along with high incidence of associated anomalies make the surgical management a real challenge. Currently, there are two strategies for managing giant omphaloceles, staged surgical closure and nonoperative delayed closure. The combined treatment with PPP and BoNT/A injection has recently been described in adults. There is strong evidence on safety and efficacy of the use of BoNT/As in other areas of pediatrics and no recent reports of PPP use in children. Also, there are no data available about the combination of both techniques in pediatric population. The purpose of this manuscript is to report a case of a 7-year-old female child that was referred to our institution with a large ventral hernia secondary to omphalocele. We opted for a combined approach with BoNT/A injection and PPP before the definitive surgery. The surgical result was great with midline closure with no tension and no need for prosthetic substitution or component separation needed. To our knowledge, this is the first case report of BoNT/A injection and PPP for large ventral hernias in children. BoNT/A application was safe and the PPP technique was also proved to be applicable on children. We believe that the combination of BoNT/A and PPP presented to be a safe approach with an excellent result, particularly for not needing abdominal wall prosthetic substitution.

Incisional hernia repair with plication and utilization of Botox injections: First case report from Saudi Arabia for a 19-year-old female

This article reports on the use of Botox preoperatively for the treatment of a complex ventral hernia which would have typically been treated with component separation technique. The case demonstrates that using the recently developed technique can aid in performing a tension-free hernia repair with potentially lower complication and recurrence rates.