Three-dimensional hernia analysis: the impact of size on surgical outcomes

The carolinas crossover, a preperitoneal crossover for enhanced-view totally extraperitoneal (eTEP) ventral hernia repair (VHR): a novel technique

PURPOSE

To present a novel technique of preperitoneal cross-over for eTEP VHR.

METHODS

Patients who underwent robotic eTEP with mesh utilizing a preperitoneal cross over technique were identified using a single-institution hernia database. This novel technique involves minimally invasive access to the retro-rectus space on one side with midline cross over into the preperitoneal space on the contralateral side. Baseline demographics of the patients were obtained, and intra-operative and post-operative outcomes were reported.

RESULTS

Nine VHR patients underwent robotic eTEP with mesh using a preperitoneal crossover technique. Five patients were male, mean age was 53 ± 18.4 years, and mean BMI was 32.5 ± 4.2 kg/m2. Two patients were diabetic and 2 were previous smokers. Two of the hernias were recurrent. The average hernia defect was 96.9 ± 45.5 cm2 and the average mesh size was 593.3 ± 168.2 cm2. Four patients underwent a unilateral TAR, while five patients did not require any component separation. All cases were CDC Class 1 wounds. All patients met discharge criteria on post-operative day 1. There was one post-operative wound occurrence which was a seroma. There were no infectious complications and no hernia recurrences. The average follow up was 1.4 ± 1.2 months.

CONCLUSIONS

Preperitoneal cross-over during eTEP ventral hernia technique is a safe technique that allows placement of a large extra-peritoneal mesh. Early patient outcomes are favorable. Larger sample size and follow-up are needed to truly assess postoperative outcomes.

Comparison of Medical Research Abstracts Written by Surgical Trainees and Senior Surgeons or Generated by Large Language Models

Importance

Artificial intelligence (AI) has permeated academia, especially OpenAI Chat Generative Pretrained Transformer (ChatGPT), a large language model. However, little has been reported on its use in medical research.

Objective

To assess a chatbot's capability to generate and grade medical research abstracts.

Design, Setting, and Participants

In this cross-sectional study, ChatGPT versions 3.5 and 4.0 (referred to as chatbot 1 and chatbot 2) were coached to generate 10 abstracts by providing background literature, prompts, analyzed data for each topic, and 10 previously presented, unassociated abstracts to serve as models. The study was conducted between August 2023 and February 2024 (including data analysis).

Exposure

Abstract versions utilizing the same topic and data were written by a surgical trainee or a senior physician or generated by chatbot 1 and chatbot 2 for comparison. The 10 training abstracts were written by 8 surgical residents or fellows, edited by the same senior surgeon, at a high-volume hospital in the Southeastern US with an emphasis on outcomes-based research. Abstract comparison was then based on 10 abstracts written by 5 surgical trainees within the first 6 months of their research year, edited by the same senior author.

Main Outcomes and Measures

The primary outcome measurements were the abstract grades using 10- and 20-point scales and ranks (first to fourth). Abstract versions by chatbot 1, chatbot 2, junior residents, and the senior author were compared and judged by blinded surgeon-reviewers as well as both chatbot models. Five academic attending surgeons from Denmark, the UK, and the US, with extensive experience in surgical organizations, research, and abstract evaluation served as reviewers.

Results

Surgeon-reviewers were unable to differentiate between abstract versions. Each reviewer ranked an AI-generated version first at least once. Abstracts demonstrated no difference in their median (IQR) 10-point scores (resident, 7.0 [6.0-8.0]; senior author, 7.0 [6.0-8.0]; chatbot 1, 7.0 [6.0-8.0]; chatbot 2, 7.0 [6.0-8.0]; P = .61), 20-point scores (resident, 14.0 [12.0-7.0]; senior author, 15.0 [13.0-17.0]; chatbot 1, 14.0 [12.0-16.0]; chatbot 2, 14.0 [13.0-16.0]; P = .50), or rank (resident, 3.0 [1.0-4.0]; senior author, 2.0 [1.0-4.0]; chatbot 1, 3.0 [2.0-4.0]; chatbot 2, 2.0 [1.0-3.0]; P = .14). The abstract grades given by chatbot 1 were comparable to the surgeon-reviewers' grades. However, chatbot 2 graded more favorably than the surgeon-reviewers and chatbot 1. Median (IQR) chatbot 2-reviewer grades were higher than surgeon-reviewer grades of all 4 abstract versions (resident, 14.0 [12.0-17.0] vs 16.9 [16.0-17.5]; P = .02; senior author, 15.0 [13.0-17.0] vs 17.0 [16.5-18.0]; P = .03; chatbot 1, 14.0 [12.0-16.0] vs 17.8 [17.5-18.5]; P = .002; chatbot 2, 14.0 [13.0-16.0] vs 16.8 [14.5-18.0]; P = .04). When comparing the grades of the 2 chatbots, chatbot 2 gave higher median (IQR) grades for abstracts than chatbot 1 (resident, 14.0 [13.0-15.0] vs 16.9 [16.0-17.5]; P = .003; senior author, 13.5 [13.0-15.5] vs 17.0 [16.5-18.0]; P = .004; chatbot 1, 14.5 [13.0-15.0] vs 17.8 [17.5-18.5]; P = .003; chatbot 2, 14.0 [13.0-15.0] vs 16.8 [14.5-18.0]; P = .01).

Conclusions and Relevance

In this cross-sectional study, trained chatbots generated convincing medical abstracts, undifferentiable from resident or senior author drafts. Chatbot 1 graded abstracts similarly to surgeon-reviewers, while chatbot 2 was less stringent. These findings may assist surgeon-scientists in successfully implementing AI in medical research.

Deep learning model utilizing clinical data alone outperforms image-based model for hernia recurrence following abdominal wall reconstruction with long-term follow up

BACKGROUND

Deep learning models (DLMs) using preoperative computed tomography (CT) imaging have shown promise in predicting outcomes following abdominal wall reconstruction (AWR), including component separation, wound complications, and pulmonary failure. This study aimed to apply these methods in predicting hernia recurrence and to evaluate if incorporating additional clinical data would improve the DLM's predictive ability.

METHODS

Patients were identified from a prospectively maintained single-institution database. Those who underwent AWR with available preoperative CTs were included, and those with < 18 months of follow up were excluded. Patients were separated into a training (80%) set and a testing (20%) set. A DLM was trained on the images only, and another DLM was trained on demographics only: age, sex, BMI, diabetes, and history of tobacco use. A mixed-value DLM incorporated data from both. The DLMs were evaluated by the area under the curve (AUC) in predicting recurrence.

RESULTS

The models evaluated data from 190 AWR patients with a 14.7% recurrence rate after an average follow up of more than 7 years (mean ± SD: 86 ± 39 months; median [Q1, Q3]: 85.4 [56.1, 113.1]). Patients had a mean age of 57.5 ± 12.3 years and were majority (65.8%) female with a BMI of 34.2 ± 7.9 kg/m2. There were 28.9% with diabetes and 16.8% with a history of tobacco use. The AUCs for the imaging DLM, clinical DLM, and combined DLM were 0.500, 0.667, and 0.604, respectively.

CONCLUSIONS

The clinical-only DLM outperformed both the image-only DLM and the mixed-value DLM in predicting recurrence. While all three models were poorly predictive of recurrence, the clinical-only DLM was the most predictive. These findings may indicate that imaging characteristics are not as useful for predicting recurrence as they have been for other AWR outcomes. Further research should focus on understanding the imaging characteristics that are identified by these DLMs and expanding the demographic information incorporated in the clinical-only DLM to further enhance the predictive ability of this model.

Anatomical Variation of Abdominal Wall Musculature: An Objective Assessment Using Cross-Sectional Imaging

Purpose: To determine normal anatomical variation of abdominal wall musculature. Methods: A retrospective analysis of CT scans was performed on adults (>18 years) with normal abdominal wall muscles. Two radiologists analysed the images independently. Distances from three fixed points in the midline were measured. The fixed points were; P1, mid-way between xiphoid and umbilicus, P2, at the umbilicus, and P3, mid-way between umbilicus and pubic symphysis. From these three fixed points the following measurements were recorded; midline to lateral innermost border of the abdominal wall musculature, midline to lateral edge of rectus abdominis muscle, and midline to medial edges of all three lateral abdominal wall muscles. To obtain aponeurotic width, rectus abdominis width was subtracted from the distance to medial edge of lateral abdominal wall muscle. Results: Fifty normal CT scan were evaluated from between March 2023 to August 2023. Mean width of external oblique aponeurosis at P1 was 16.2 mm (IQR 9.2 mm to 20.7 mm), at P2 was 23.5 mm (IQR 14 mm to 33 mm), and at P3 no external oblique muscle was visible. Mean width of the internal oblique aponeurosis at P1 was 32.1 mm (IQR 17.5 mm to 45 mm), at P2 was 10.13 (IQR 1 mm to 17.5 mm), and at P3 was 9.2 mm (IQR 3.0 mm to 13.7 mm). Mean width of the transversus abdominis aponeurosis at P1 was -25.1 mm (IQR 37.8 mm to -15.0 mm), at P2 was 29.4 mm (IQR 20 mm to 39.8 mm), and at P3 was 20.3 mm (IQR 12 mm to 29 mm). Conclusion: In this study we describe normal anatomical variation of the abdominal wall muscles. Assessing this variability on the pre-operative CT scans of ventral hernia patients allows for detailed operative planning and decision making.

Body Mass Index Effect on Minimally Invasive Ventral Hernia Repair: A Systematic Review and Meta-analysis

PURPOSE

Obesity is one of the most important risk factors for complications after ventral hernia repair (VHR), and minimally invasive (MIS) techniques are preferred in obese patients as they minimize wound complications. It is common practice to attempt weight loss to achieve a specific body mass index (BMI) goal; however, patients are often unable to reach it and fail to become surgical candidates. Therefore, we aim to perform a meta-analysis of studies comparing outcomes of obese and nonobese patients undergoing laparoscopic or robotic VHR.

PATIENTS AND METHODS

A literature search of PubMed, Scopus, and Cochrane Library databases was performed to identify studies comparing obese and nonobese patients undergoing MIS VHR. Postoperative outcomes were assessed by means of pooled analysis and meta-analysis. Statistical analysis was performed using RevMan 5.4. Heterogeneity was assessed with I2 statistics.

RESULTS

A total of 6483 studies were screened and 26 were thoroughly reviewed. Eleven studies and 3199 patients were included in the meta-analysis. BMI >40 kg/m 2 cutoff analysis included 5 studies and 1533 patients; no differences in hernia recurrence [odds ratios (OR): 1.64; 95% CI: 0.57-4.68; P = 0.36; I2 = 47%), seroma, hematoma, and surgical site infection (SSI) rates were noted. BMI >35 kg/m 2 cutoff analysis included 5 studies and 1403 patients; no differences in hernia recurrence (OR: 1.24; 95% CI: 0.71-2.16; P = 0.58; I2 = 0%), seroma, hematoma, and SSI rates were noted. BMI >30 kg/m 2 cutoff analysis included 4 studies and 385 patients; no differences in hernia recurrence (OR: 2.07; 95% CI: 0.5-8.54; P = 0.32; I2 = 0%), seroma, hematoma, and SSI rates were noted.

CONCLUSION

Patients with high BMI undergoing MIS VHR have similar hernia recurrence, seroma, hematoma, and SSI rates compared with patients with lower BMI. Further prospective studies with long-term follow-up and patient-reported outcomes are required to establish optimal management in obese patients undergoing VHR.

Defining surgical risk in octogenarians undergoing paraesophageal hernia repair

BACKGROUND

With an aging population, the utility of surgery in elderly patients, particularly octogenarians, is of increasing interest. The goal of this study was to analyze outcomes of octogenarians versus non-octogenarians undergoing paraesophageal hernia repair (PEHR).

METHODS

The Nationwide Readmission Database was queried for patients > 18 years old who underwent PEHR from 2016 to 2018. Exclusion criteria included a diagnosis of gastrointestinal malignancy or a concurrent bariatric procedure. Patients ≥ 80 were compared to those 18-79 years old using standard statistical methods, and subgroup analyses of elective and non-elective PEHRs were performed.

RESULTS

From 2016 to 2018, 46,450 patients were identified with 5425 (11.7%) octogenarians and 41,025 (88.3%) non-octogenarians. Octogenarians were more likely to have a non-elective operation (46.3% vs 18.2%, p < 0.001), and those undergoing non-elective PEHR had a higher mortality (5.5% vs 1.2%, p < 0.001). Outcomes were improved with elective PEHR, but octogenarians still had higher mortality (1.3% vs 0.2%, p < 0.001), longer LOS (3[2, 5] vs 2[1, 3] days, p < 0.001), and higher readmission rates within 30 days (11.1% vs 6.5%, p < 0.001) compared to non-octogenarian elective patients. Multivariable logistic regression showed that being an octogenarian was not independently predictive of mortality (odds ratio (OR) 1.373[95% confidence interval 0.962-1.959], p = 0.081), but a non-elective operation was (OR 3.180[2.492-4.057], p < 0.001). Being an octogenarian was a risk factor for readmission within 30 days (OR 1.512[1.348-1.697], p < 0.001).

CONCLUSIONS

Octogenarians represented a substantial proportion of patients undergoing PEHR and were more likely to undergo a non-elective operation. Being an octogenarian was not an independent predictor of perioperative mortality, but a non-elective operation was. Octogenarians' morbidity and mortality was reduced in elective procedures but was still higher than non-octogenarians. Elective PEHR in octogenarians is reasonable but should involve a thorough risk-benefit analysis.

Preoperative Optimization for Abdominal Wall Reconstruction

Patients requiring abdominal wall reconstruction may have medical comorbidities and/or complex defects. Comorbidities such as smoking, diabetes, obesity, cirrhosis, and frailty have been associated with an increased risk of postoperative complications. Prehabilitation strategies are variably associated with improved outcomes. Large hernia defects and loss of domain may present challenges in achieving fascial closure, an important part of restoring abdominal wall function. Prehabilitation of the abdominal wall can be achieved with the use of botulinum toxin A, and preoperative progressive pneumoperitoneum.

Predicting rare outcomes in abdominal wall reconstruction using image-based deep learning models

BACKGROUND

Deep learning models with imbalanced data sets are a challenge in the fields of artificial intelligence and surgery. The aim of this study was to develop and compare deep learning models that predict rare but devastating postoperative complications after abdominal wall reconstruction.

METHODS

A prospectively maintained institutional database was used to identify abdominal wall reconstruction patients with preoperative computed tomography scans. Conventional deep learning models were developed using an 8-layer convolutional neural network and a 2-class training system (ie, learns negative and positive outcomes). Conventional deep learning models were compared to deep learning models that were developed using a generative adversarial network anomaly framework, which uses image augmentation and anomaly detection. The primary outcomes were receiver operating characteristic values for predicting mesh infection and pulmonary failure.

RESULTS

Computed tomography scans from 510 patients were used with a total of 10,004 images. Mesh infection and pulmonary failure occurred in 3.7% and 5.6% of patients, respectively. The conventional deep learning models were less effective than generative adversarial network anomaly for predicting mesh infection (receiver operating characteristic 0.61 vs 0.73, P < .01) and pulmonary failure (receiver operating characteristic 0.59 vs 0.70, P < .01). Although the conventional deep learning models had higher accuracies/specificities for predicting mesh infection (0.93 vs 0.78, P < .01/.96 vs .78, P < .01) and pulmonary failure (0.88 vs 0.68, P < .01/.92 vs .67, P < .01), they were substantially compromised by decreased model sensitivity (0.25 vs 0.68, P < .01/.27 vs .73, P < .01).

CONCLUSION

Compared to conventional deep learning models, generative adversarial network anomaly deep learning models showed improved performance on imbalanced data sets, predominantly by increasing model sensitivity. Understanding patients who are at risk for rare but devastating postoperative complications can improve risk stratification, resource utilization, and the consent process.

Impact of COVID-19 on volume of elective and nonelective ventral hernia repair

BACKGROUND

The significant decrease in elective surgery during the COVID-19 pandemic prompted fears that there would be an increase in emergency or urgent operations for certain disease states. The impact of COVID-19 on ventral hernia repair is unknown. This study aimed to compare volumes of elective and nonelective ventral hernia repairs performed pre-COVID-19 with those performed during the COVID-19 pandemic.

METHODS

An analysis of a prospective database from 8 hospitals capturing patient admissions with the International Classification of Diseases, Tenth Revision Procedure Coding System for ventral hernia repair from January 2017 through June 2021 were included. During, COVID-19 was defined as on or after March 2020.

RESULTS

Comparing 3,558 ventral hernia repairs pre-COVID-19 with 1,228 during COVID-19, there was a significant decrease in the mean number of elective ventral hernia repairs per month during COVID-19 (pre-COVID-19: 61 ± 5 vs during COVID-19 19: 39 ± 11; P < .001), and this persisted after excluding the initial 3-month COVID-19 surge (61 ± 5 vs 42 ± 9; P < .001). There were fewer nonelective cases during the initial 3-month COVID-19 surge (32 ± 9 vs 24 ± 4; P = .031), but, excluding the initial surge, there was no difference in nonelective volume (32 ± 9 vs 33 ± 8; P = .560). During COVID-19, patients had lower rates of congestive heart failure (elective: 9.0% vs 6.6%; P = .0047; nonelective: 17.7% vs 11.6%; P < .001) and chronic obstructive pulmonary disease (elective: 13.7% vs 10.2%; P = .017; nonelective: 17.9% vs 12.0%; P < .001) and underwent fewer component separations (10.2% vs 6.4%; P ≤ .001). Intensive care unit admissions decreased for elective ventral hernia repairs (7.7% vs 5.0%; P = .016). Length of stay, cost, and readmission were similar between groups.

CONCLUSION

Elective ventral hernia repair volume decreased during COVID-19 whereas nonelective ventral hernia repairs transiently decreased before returning to baseline. During COVID-19, patients appeared to be lower risk and less complex. The possible impact of the more complex patients delaying surgery is yet to be seen.

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.

Prediction models in hernia repair: a systematic review

BACKGROUND

Hernias can present with unique challenges when it comes to management and repair. Prediction models can be a useful tool for clinicians to better anticipate and understand the severity of a hernia, the type of surgical technique, or presurgical planning that may be required to treat the patient, and the risk of complications. Our goal is to evaluate and consolidate prediction models in hernia repair present in the literature for which physicians can reference to best improve patient outcomes and postoperative management.

METHODS

We performed a literature search in PubMed using keywords, "rectus width to defect width ratio," "predicting myofascial release," "computed tomography hernia repair prediction," "component separation radiology prediction hernia," "fat volume and hernia repair," "body morphometrics and Query hernia repair," "body morphometrics and reherniation," "computed tomography findings and risk of emergency hernia repair," "loss of domain and hernia radiology," and "volumetry and hernia repair." We searched for publications that used radiographic parameters to predict hernia severity, interventions, and outcomes.

RESULTS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), we found twenty-three studies related to prediction models in hernia repair published between 2000 and 2021. We summarized studies pertaining to predicting acute care, predicting operative planning with loss of domain and component separation, predicting complications, paraesophageal hernia predictions, and predicting postoperative respiratory complications.

CONCLUSION

Radiographic prediction models can be an objective and efficient way for surgeons to analyze hernias and better understand a patient's situation so that they can inform patients about the best treatment options and the risk of complications.

Nationwide increase in component separation without concomitant rise in readmissions: A nationwide readmissions database analysis

BACKGROUND

The use of component separation technique (CST) in complex abdominal wall reconstruction (AWR) increases the rate of primary musculofascial closure but can be associated with increased wound complications, which may require readmission. This study examines 3-year trends in readmissions for patients undergoing AWR with or without CST.

METHODS

The Nationwide Readmissions Database was queried for patients undergoing elective AWR from 2016-2018. CST, demographic characteristics, and 90-day complications and readmissions were determined. CST versus non-CST readmissions were compared, including matched subgroups. Standard statistics and logistic regression were used.

RESULTS

Over the 3-year period, 94,784 patients underwent AWR. There was an annual increase in the prevalence of CST: 4.0% in 2016; 6.1% in 2017; 6.7% in 2018 (P < .01), which is a 67.5% upsurge during that time. Most cases (82.3%) occurred at urban teaching hospitals, which had more comorbid patients (P < .01). The yearly 90-day readmission rate did not change: 16.0%, 18.2%, and 16.9% (P = .26). Readmissions were higher for CST patients than non-CST patients (17.1% vs 15.7%), but not in the matched subgroup (17.0% vs 16.4%; P = .41). Most commonly, readmissions were for infection (28.3%); 14.3% of readmitted patients underwent reoperation. Smoking, morbid obesity, diabetes, chronic lung disease, urban-teaching hospital status, and increased length of stay increased the chance of readmission (all P < .05).

CONCLUSION

From 2016 to 2018, the use of CST increased 67.5% nationwide without an increase in readmissions. As we look toward clinical targets to reduce risk of readmission, modifiable health conditions, such as smoking, morbid obesity, and diabetes should be targeted during the prehabilitation process.

Outcomes and CT scan three-dimensional volumetric analysis of emergent paraesophageal hernia repairs: predicting patients who will require emergent repair

Introduction

Elective repair versus watchful waiting remains controversial in paraesophageal hernia (PEH) patients. Generation of predictive factors to determine patients at greatest risk for emergent repair may prove helpful. The aim of this study was to evaluate patients undergoing elective versus emergent PEH repair and supplement this comparison with 3D volumetric analysis of hiatal defect area (HDA) and intrathoracic hernia sac volume (HSV) to determine risk factors for increased likelihood of emergent repair.

Methods

A retrospective review of a prospectively enrolled, single-center hernia database was performed on all patients undergoing elective and emergent PEH repairs. Patients with adequate preoperative computed tomography (CT) imaging were analyzed using volumetric analysis software.

Results

Of the 376 PEH patients, 32 (8.5%) were emergent. Emergent patients had lower rates of preoperative heartburn (68.8%vs85.1%, p = 0.016) and regurgitation (21.9%vs40.2%, p = 0.04), with similar rates of other symptoms. Emergent patients more frequently had type IV PEHs (43.8%vs13.5%, p < 0.001). Volumetric analysis was performed on 201 patients, and emergent patients had a larger HSV (805.6 ± 483.5vs398.0 ± 353.1cm³, p < 0.001) and HDA (41.7 ± 19.5vs26.5 ± 14.7 cm², p < 0.001). In multivariate analysis, HSV increase of 100cm³ (OR 1.17 CI 1.02–1.35, p = 0.022) was independently associated with greater likelihood of emergent repair. Post-operatively, emergent patients had increased length of stay, major complication rates, ICU utilization, reoperation, and mortality (all p < 0.05). Emergent group recurrence rates were higher and occurred faster secondary to increased use of gastropexy alone as treatment (p > 0.05). With a formal PEH repair, there was no difference in rate or timing of recurrence.

Conclusions

Emergent patients are more likely to suffer complications, require ICU care, have a higher mortality, and an increased likelihood of reoperation. A graduated increase in HSV increasingly predicts the need for an emergent operation. Those patients presenting electively with a large PEH may benefit from early elective surgery.

Development and Validation of Image-Based Deep Learning Models to Predict Surgical Complexity and Complications in Abdominal Wall Reconstruction

Importance

Image-based deep learning models (DLMs) have been used in other disciplines, but this method has yet to be used to predict surgical outcomes.

Objective

To apply image-based deep learning to predict complexity, defined as need for component separation, and pulmonary and wound complications after abdominal wall reconstruction (AWR).

Design, Setting, and Participants

This quality improvement study was performed at an 874-bed hospital and tertiary hernia referral center from September 2019 to January 2020. A prospective database was queried for patients with ventral hernias who underwent open AWR by experienced surgeons and had preoperative computed tomography images containing the entire hernia defect. An 8-layer convolutional neural network was generated to analyze image characteristics. Images were batched into training (approximately 80%) or test sets (approximately 20%) to analyze model output. Test sets were blinded from the convolutional neural network until training was completed. For the surgical complexity model, a separate validation set of computed tomography images was evaluated by a blinded panel of 6 expert AWR surgeons and the surgical complexity DLM. Analysis started February 2020.

Exposures

Image-based DLM.

Main Outcomes and Measures

The primary outcome was model performance as measured by area under the curve in the receiver operating curve (ROC) calculated for each model; accuracy with accompanying sensitivity and specificity were also calculated. Measures were DLM prediction of surgical complexity using need for component separation techniques as a surrogate and prediction of postoperative surgical site infection and pulmonary failure. The DLM for predicting surgical complexity was compared against the prediction of 6 expert AWR surgeons.

Results

A total of 369 patients and 9303 computed tomography images were used. The mean (SD) age of patients was 57.9 (12.6) years, 232 (62.9%) were female, and 323 (87.5%) were White. The surgical complexity DLM performed well (ROC = 0.744; P < .001) and, when compared with surgeon prediction on the validation set, performed better with an accuracy of 81.3% compared with 65.0% (P < .001). Surgical site infection was predicted successfully with an ROC of 0.898 (P < .001). However, the DLM for predicting pulmonary failure was less effective with an ROC of 0.545 (P = .03).

Conclusions and Relevance

Image-based DLM using routine, preoperative computed tomography images was successful in predicting surgical complexity and more accurate than expert surgeon judgment. An additional DLM accurately predicted the development of surgical site infection.

Validation of a simple technique of volumetric analysis of complex incisional hernias without 3D CT scan reconstruction

PURPOSE

Volumetric analysis is being increasingly utilized in the preoperative evaluation of complex incisional hernias. Three-dimensional (3D) reconstruction of abdominal computed tomography (CT) scan has been used to obtain surface area (SA) and volume (Vol.) measurements, while others have used simple mathematical formulas to obtain SA and Vol. estimates without 3D reconstruction. Our objective was to assess the correlation of SA and Vol. measurements and estimates of complex incisional hernias.

METHODS

We conducted a retrospective agreement study of adults who underwent abdominal wall reconstruction from 2007 to 2018. Demographics, hernia characteristics, and operative data were collected from the medical record. SA and Vol. measurements were obtained after 3D CT reconstruction. Linear CT variables were obtained independently by two surgeons and SA and Vol. estimates were calculated. Because both surgeons reported similar results, only lead author values are reported in the abstract. We used Pearson's correlation coefficient (r) to assess inter-rater agreement and the agreement between SA and Vol. measurements and estimates.

RESULTS

A total of 108 patients were eligible for analysis. The mean age was 57 ± 11 years and 53 (49%) were female. 42 (39%) hernias were recurrent, 10 (9%) patients had a stoma, and 9 (8%) had a history of open abdomen. The mean defect width was 11 ± 4 cm and mean defect surface area (DSA) was 150 ± 95 cm². Inter-rater agreement of SA and Vol. estimates was high (r ≥ 0.80). There was high correlation between SA and Vol. measurements and estimates for DSA, hernia sac volume (HSV), abdominal cavity volume (ACV), and HSV/ACV ratio (r = 0.81, 0.89, 0.94 and 0.91, respectively).

CONCLUSION

SA and Vol. estimates demonstrated high level of agreement with SA and Vol. measurements using 3D reconstruction. SA and Vol. estimates can be obtained using simple mathematical formulas using easily obtained linear variables negating the need for the time and effort consuming 3D reconstruction.

Preoperative botulinum toxin A injection in complex abdominal wall reconstruction- a propensity-scored matched study

INTRODUCTION

Fascial closure during complex abdominal wall reconstruction (AWR) improves recurrence and wound infection rates. To facilitate fascial closure in massive ventral hernias preoperative Botulinum Toxin A (BTA) injection can be used.

METHODS

2:1 propensity-scored matching of patients undergoing AWR with and without BTA was performed based on BMI, defect width, and loss of domain using CT-volumetric analysis.

RESULTS

145 patients without BTA and 75 with BTA were comparable on hernia size (240vs251cm², p = 0.589) and hernia volume (1405vs1672cm³, p = 0.243). Patients with BTA had higher wound class (CDC≥3 37%vs13%, p < 0.001). Patients with BTA had a higher fascial closure rate (92%vs81%, p = 0.036), received more components separation (61%vs47%, p = 0.042), lower wound infection rate (12%vs26%,p = 0.019) and comparable recurrence rates (9%vs12%, p = 0.589). Recurrences occurred more often without complete fascial closure compared to patients with (33%vs7%, p < 0.001).

CONCLUSION

In patients with massive ventral hernias and severe loss of domain, preoperative BTA-injection improves fascial closure rates during AWR.

Image-guided botulinum toxin injection in the lateral abdominal wall prior to abdominal wall reconstruction surgery: review of techniques and results

Ventral hernias represent the most common complication after abdominal surgery. Loss of domain and/or large ventral hernias in patients are especially challenging for surgeons to manage, but preoperative image-guided botulinum toxin injection has emerged as an effective adjunct to abdominal wall surgery. Loss of domain is caused by chronic muscle retraction of the lateral abdominal wall and leads to an irreducible protrusion of abdominal viscera into the hernia sac. Botulinum toxin can be used in the oblique muscles as a chemical component relaxation technique to aid abdominal wall reconstruction. Intramuscular botulinum toxin injection causes functional denervation by blocking neurotransmitter acetylcholine release resulting in flaccid paralysis and elongation of lateral abdominal wall muscles, increasing the rate of fascial closure during abdominal wall reconstruction, and decreasing recurrence rates. In total, 200-300 units of onabotulinumtoxinA (Botox®) or 500 units of abobotulinumtoxinA (Dypsort®) in a 2:1 dilution with normal saline is most commonly used. Botulinum toxin can be injected with ultrasonographic, EMG, or CT guidance. Injection should be performed at least 2 weeks prior to abdominal wall reconstruction, for maximal effect during surgery. At minimum, botulinum toxin should be injected into the external and internal oblique muscles at three separate sites bilaterally for a total of six injections. Although botulinum toxin use for abdominal wall reconstruction is currently not indicated by the Food and Drug Administration, it is safe with only minor complications reported in literature.

The Effects of Preoperative Botulinum Toxin A Injection on Abdominal Wall Reconstruction

BACKGROUND

Fascial closure significantly reduces postoperative complications and hernia recurrence after abdominal wall reconstruction (AWR), but can be challenging in massive ventral hernias.

METHODS

A prospective single-institution cohort study was performed to examine the effects of preoperative injection of botulinum toxin A (BTA) in patients undergoing AWR for midline or flank hernias.

RESULTS

A total of 108 patients underwent BTA injection with average 243 units, mean 32.5 days before AWR, without complications. Comorbidities included diabetes (31%), history of smoking (27%), and obesity (mean body mass index 30.5 ± 7.7). Hernias were recurrent in 57%, massive (mean defect width 15.3 ± 5.5 cm; hernia sac volume 2154 ± 3251 cm³) and had significant loss of domain (mean 46% visceral volume outside abdominal cavity). Contamination was present in 38% of patients. Fascial closure was achieved in 91%, with 57% requiring component separation techniques (CSTs). Subxiphoidal hernias needed a form of CST in 88% compared with 50% for hernia not extending subxiphoidal (P < 0.001). Mesh augmentation was used in 98%. Postoperative complications occurred in 40%: 19% surgical site occurrences, 12% surgical site infections, and 7% respiratory failure requiring intubation, 2% mesh infection and no fascial dehiscence. Recurrence was identified in seven patients after mean 14 months of follow-up. Patients undergoing AWR with CST had more surgical site occurrences (29 versus 7%, p0.003) and respiratory failures (18 versus 0%, P = 0.002) than patients who did not require CST.

CONCLUSIONS

In patients with massive ventral hernias, the use of preoperative BTA injections for AWR is safe and is associated with high fascial closure rates and excellent recurrence rates.

Computed Tomography Image Analysis in Abdominal Wall Reconstruction: A Systematic Review

Ventral hernias are a complex and costly burden to the health care system. Although preoperative radiologic imaging is commonly performed, the plethora of anatomic features present and available in routine imaging are seldomly quantified and integrated into patient selection, preoperative risk stratification, and perioperative planning. We herein aimed to critically examine the current state of computed tomography feature application in predicting surgical outcomes.

Methods

A systematic review was conducted in accordance with the Preferred Reporting Items for a Systematic Review and Meta-Analysis (PRISMA) checklist. PubMed, MEDLINE, and Embase databases were reviewed under search syntax "computed tomography imaging" and "abdominal hernia" for papers published between 2000 and 2020.

Results

Of the initial 1922 studies, 12 papers met inclusion and exclusion criteria. The most frequently used radiologic features were hernia volume (n = 9), subcutaneous fat volume (n = 5), and defect size (n = 8). Outcomes included both complications and need for surgical intervention. Median area under the curve (AUC) and odds ratio were 0.68 (±0.16) and 1.12 (±0.39), respectively. The best predictive feature was hernia neck ratio > 2.5 (AUC 0.903).

Conclusions

Computed tomography feature selection offers hernia surgeons an opportunity to identify, quantify, and integrate routinely available morphologic tissue features into preoperative decision-making. Despite being in its early stages, future surgeons and researchers will soon be able to integrate 3D volumetric analysis and complex machine learning and neural network models to improvement patient care.

Robotic Sugarbaker parastomal hernia repair: technique and outcomes

PURPOSE

To present a novel technique for the repair of parastomal hernias.

METHODS

A total of 15 patients underwent parastomal hernia repair. A robotic Sugarbaker technique was utilized for repair. The fascial defect was closed prior to robotic intraperitoneal placement of the mesh. Baseline demographics of the patients were obtained, and intra-operative and post-operative outcomes were tracked.

RESULTS

The etiology of the ostomies was oncologic in all but three patients. Five of the stomas were urostomies (33.3%). Patient characteristics were as follows: age 64.9.1 ± 9.3 years, BMI 30.1 ± 4.7 kg/m², smoking history 60.0%, and diabetes 6.7%. The mean size of the hernia defect was 46.0 ± 40.1 cm² with a mesh size of 372.0 ± 101.2 cm². The mean operative time was 182.0 ± 51.9 min. In seven patients, an inferolateral preperitoneal flap was created for mesh placement. Intraoperatively, only one enterotomy was made during dissection, which was repaired without complication. The mean length of stay was 4.2 ± 1.9 days. There was only one hernia recurrence (6.7%). There were no wound complications, surgical site infections, or mesh infections. A mean follow-up time of 14.2 ± 9.4 months was achieved.

CONCLUSIONS

Robotic Sugarbaker parastomal hernia repair is a safe and effective technique. The results demonstrate the feasibility of fascial closure with this technique and a low recurrence rate. The authors propose this technique should be widely considered for parastomal hernia repair.

Laparoscopic Ventral Hernia Repair in the Geriatric Population : An Assessment of Long-Term Outcomes and Quality of Life

OBJECTIVES

Laparoscopic ventral hernia repair (LVHR) has been shown to decrease wound complications and length of stay (LOS) but results in more postoperative discomfort. The benefits of LVHR for the growing geriatric population are unclear. The aim of our study is to evaluate long-term outcomes and quality of life (QOL) after LVHR in the geriatric population.

METHODS

A prospectively collected single-center database was queried for all patients who underwent LVHR (1999-2019). Age groups were defined as <40 (young), 40-64 (middle age), and ≥65 years (geriatric). QOL was assessed with the Carolinas Comfort Scale.

RESULTS

LVHR was performed in 1181 patients, of which 13.4% were young, 61.6% middle aged, and 25.0% geriatric. Hernia defect size (64.2 ± 94.4 vs 79.9 ± 102.4 vs 84.7 ± 110.0 cm²) and number of comorbidities (2.2 ± 2.1 vs 3.2 ± 2.2 vs 4.3 ± 2.2) increased with age (all P < .05). LOS increased with age (2.9 ± 2.5 vs 3.8 ± 2.9 vs 5.2 ± 5.3 days, P < .0001). Rates of postoperative cardiac events, pneumonia, respiratory failure, wound complication, reoperation, and death were similar (P > .05). Geriatric patients had increased rate of ileus and urinary retention (all P < .05). Overall recurrence rate was 5.7% with an average follow-up of 43.5 months, with no differences in recurrence between groups (P > .05). Geriatric patients had better overall QOL at 2 weeks (P = .0008) and similar QOL at 1, 6, and 12 months.

DISCUSSION

LVHR offers excellent results in the geriatric population. Despite having increased rates of comorbidities and larger hernia defects, which may relate to LOS, rates of complications and recurrence were similar compared with younger cohorts, with better short-term QOL.

Obesity and ventral hernia in the context of drug addiction and mental instability: a complex scenario successfully treated with preoperative progressive pneumoperitoneum

Surgery in loss of domain hernia can result in high morbidity and mortality. Chronic muscle retraction along with the reduced volume of the peritoneal cavity can lead to potential problems such as abdominal compartment syndrome, ventilatory restriction and an elevated risk of hernia recurrence. This is affected even further by obesity; a high body mass index is strongly associated with poor outcomes after ventral hernia repair. In these individuals, preoperative preparation is vital as it can reduce surgical risks and improve patients’ outcomes. There are many strategies available. Nonetheless, an individualized case approach by a multidisciplinary team is crucial to accurately treat this troublesome pathology. We present the case of a 41-year-old obese patient with a loss of domain ventral hernia. As he had a drug addiction and several psychologic difficulties, a tailored approach was needed to successfully treat the hernia. After preoperative preparation and surgery, the patient underwent full recovery.