OC-034 EVIDENCE-BASED CHANGES IN PERI-OPERATIVE PATIENT CARE IN A TERTIARY HERNIA CENTER(THC): PROSPECTIVE STUDY OF OUTCOMES OVER 18 YEARS AND 1842 OPEN PREPERITONEAL VENTRAL HERNIA REPAIRS(OPPVHR)

Background

Over 18 years, a THC frequently changed patient-care protocols according to repeated reviews of our prospectively collected data outcomes, which have been published in peer-reviewed journals. This study aimed to describe these progressive, evidence-based changes and the subsequent results in PP-VHR.

Methods

Prospective, tertiary hernia center data(2004–2021) was examined for patients undergoing midline open PP-VHR with mesh. “Early”(2004–2012) and “Recent”(2013–2021) groups were based on surgery date.

Results

Comparison of Early(n=675) versus Recent(n=1,167) groups showed that Recent patients were older (56.9±12.6vs58.7±12.1 years;p<0.001), more comorbid(3.6±2.2vs5.2±2.6 diagnoses;p<0.001), lower BMI(33.5±8.3 vs 32.0±6.8 kg/m2; p=0.003), more prior failed VHR(46.5% vs 60.8%; p<0.001), larger hernia defects(199.7±232.8vs214.4±170.5 cm2;p<0.001), more CDC-class 3/4 wounds(11.3%vs18.6%;p<0.001), more biologic mesh(10.5% vs 25.4%;p<0.001), component separations(CST; 22.5%vs45.7%;p<0.001), and more pre-op Botox(0%vs12.3%;p<0.01). Wound complication(26.7%vs13.2%;p<0.001), mesh infection(3.1%vs0.9%;p<0.01), and hernia recurrence rates decreased over time(7.1%vs2.4%;p<0.001) with long-term follow-up(4.2±4.1vs2.2±1.8years;p<0.001).

Comparing respective multivariable analyses (Early vs Recent), wound complications were associated with panniculectomy(OR[95%CI]:2.9[1.9–4.5],p<0.001 vs 2.1[1.4–3.3],p<0.01), contaminated wounds(2.1[1.1–3.7],p=0.02 vs 1.8[1.1–3.1],p=0.02), anterior CST(1.8[1.1–2.9], p=0.02 vs 3.2[1.9–5.3],p<0.01), and operative time(per minute:1.01[1.008–1.015], p<0.01 vs 1.004[1.001–1.007], p<0.01) in both time periods. Diabetes(2.6[1.7–4.0],p<0.01) and tobacco(1.8[1.1–2.9], p=0.02) were only significant in the Early group with the Recent group requirements for preop smoking cessation and a HgbA1C of <7.2. In both groups, recurrence was associated with wound complication(8.9[4.1–20.1],p<0.01 vs 3.4[1.3–8.2].p<0.01) and prior failed VHR hernias(4.9[2.3–11.5],p<0.01 vs 2.1[1.1–4.2],p=0.036).

Conclusion

Despite increased patient and hernia complexity over time, detecting and implementing best practices, as determined by repeated self-analysis of a THC's data, significantly improved patient outcomes, including wound and mesh complications and recurrence.

OC-061 IMAGE-BASED DEEP LEARNING MODELS (DLMS) IDENTIFY ABDOMINAL WALL RECONSTRUCTION (AWR) PATIENTS RECEIVING PREOPERATIVE BOTULINUM TOXIN A (BTA) WHO REQUIRE COMPONENT SEPARATION TECHNIQUE (CST)

Aim

Preoperative BTA facilitates muscle/fascia elongation and fascial closure, which increases the durability of hernia repair and may reduce requirement for CST. The aim of this study was to develop image-based DLMs that predict whether patient will require CST if injected with BTA prior to surgery.

Methods

An institutional database was used to identify AWR patients who received preoperative BTA and had preoperative CT imaging. Axial CT cuts of the hernias were rendered to train and develop a DLM. The primary outcome was a ROC for predicting CST. The DLM was tested on CT scans from a pre-identified subset of patients who underwent CST and did not receive preoperative BTA.

Results

There were 116 patients who met criteria (4,580 CT images). Of these patients, 69 (59.5%) required CST (2884 images); 47 patients (40.5%) did not undergo CST (1,696 images). The DLM ROC was 0.78 (Figure 1); accuracy, sensitivity, and specificity were 0.79, 0.86, and 0.68, respectively. There were 98 patients in the test set; 57 (58.1%) were predicted to require CST and 41 (41.9%) were not. For patients with an M1 hernia component, 21.1% were predicted to be spared CST versus 46.8% those with an M2-M5 hernia component (p=0.04).

Figure 1 Model Performance for CST Prediction

Conclusions

Image-based DLMs accurately predicted which patients receiving preoperative BTA may require CST. When the DLM was applied to a test set, patients with an M1 hernias were very likely to require CST, which is consistent with previously reported data, further validating the model.

OC-077 OPEN REPAIR OF FLANK AND LUMBAR HERNIAS (FLH): 145 CONSECUTIVE REPAIRS AT A HIGH-VOLUME, TERTIARY HERNIA CENTER

Aim

FLH present a surgical challenge due to their anatomic location, proximity to boney structures, and lack of elasticity of the surrounding muscle. With less than 1,000 cases reported, there is no uniform operative management. This is the largest study to date evaluating FLH repair (FLHR).

Materials & Methods

A prospective, single-center, hernia specific database was queried for patients who underwent open flank or lumbar hernia repair from 2004–2021. Demographics, operative characteristics, and outcomes were evaluated. Standard statistical methods were used.

Results

145 patients included 109 flank hernias and 36 lumbar hernias. The hernias resulted from prior surgery (73.3%), blunt trauma (19.7%), or primary defects (7.0%). The mean defect size was 125.7±166.8cm2, 46.9% were recurrent, and 11.0% of patients visited a pain specialist preoperatively. Mesh was commonly synthetic (92.4%), a mean of 755.9±373.4 cm2, and placed in the preperitoneal space (92.7%). Component separation technique was utilized in 16.8% of cases and pelvic bone anchor fixation in 13.8%. Preoperative chronic pain was present in 75% of patients receiving bone anchors and only 6.6% postoperatively. Complete defect closure occurred in each case. Wound infection (8.1%) and mesh infection (1.4%) were uncommon. Prolonged, postoperative discomfort was reported in 22%, half of which had chronic pain preoperatively (p<0.01). Hernia recurrence was 3.4% at 29.3±13.2 months follow-up. Recurrences occurred posteriorly in 3 and in 2 mesh infections requiring explantation.

Conclusions

Open preperitoneal repair of FLHs with synthetic mesh results in low rates of postoperative complications and hernia recurrence. Postoperative pain correlated closely with preoperative pain.

V-002 MASSIVE INGUINAL HERNIA REPAIR WITH CHEMICAL COMPONENT RELAXATION AND PREOPERATIVE PROGRESSIVE PNEUMOPERITONEUM

Inguinal hernias are one of the most common procedures performed worldwide. Conversely, massive or giant inguinal hernias; defined as extending below the midpoint of the inner thigh are very uncommon. They are often associated with loss of domain, posing a different set of challenges for the surgeon, specially creating intra-abdominal space for the displaced organs. Preoperative progressive pneumoperitoneum (PPP) coupled with chemical denervation with botulinum toxin A (BTA) is one way to increase the size of the intrabdominal cavity to aid in reduction of the hernia contents and closure of the defect.

We present a case of a 51-year-old male with a massive right inguinal hernia with complete loss of domain. The hernia sac contained the entirety of his small bowel and colon except for his proximal duodenum and distal rectum which remained intrabdominal. We preformed preoperative BTA chemical denervation and progressive pneumoperitoneum prior to staged open Inguinal hernia repair. 1 month preoperatively BTA injections were performed under ultrasound guidance into the external and internal obliques at 3 locations bilaterally and an intraabdominal catheter was placed under laparoscopic guidance. The patient was insufflated with filter air 3 times a week for 3 weeks. He then underwent open repair with preperitoneal mesh placed and orchiectomy.

OC-032 IMAGE-BASED DEEP LEARNING MODELS (DLMS) TO PREDICT LONG TERM QUALITY OF LIFE (QOL) FOLLOWING ABDOMINAL WALL RECONSTRUCTION (AWR)

Aim

To apply image-based DLMs to predict post-operative QOL following AWR.

Materials & Methods

A prospective, institutional hernia-database was queried for patients with preoperative abdominal CT-imaging, a preoperative and 1-year postoperative Carolinas Comfort Scale(CCS) survey, and no recurrence. “Symptomatic” was defined as CCS-score≥2(2=mild and bothersome). Google Xception existing architecture model was used with ImageNet database pre-initialized weights to classify symptomatic and non-symptomatic patients. Patients were divided into 80:20-training:testing samples for model generation and evaluation. Model training, test accuracies, and loss-functions were evaluated to determine performance and discriminative ability.

Results

Of 244 patients, mean age was 60.4±11.8 years, mean BMI:33.0±7.1kg/m2, female:57.1%, tobacco use:14.3%, diabetic: 24.5%. Median[IQR] hernia defect size was Exactly 180cm2[90–324]; 66.1% had a failed repair. CDC wound classifications Included: 75.9% class-I, 8.3% class-II, 9.1% class-III, 6.6% class-IV. Preoperatively, hernia-related pain(70.2%) and movement limitations(72.3%) were common. Mesh position was predominantly preperitoneal(91.6%). Median[IQR] mesh size was 900cm2[572–1050]. Anterior component separation was required in 17.9% and posterior in 20.4%.

One-year postoperatively, reported symptoms included: mesh sensation-39.5%, discomfort-37.8%, movement limitations-37.0%.

DLMs utilized 6,441-CT-images(5,097 training-sample). Proportions of symptomatic patients were 48.9%(85/174) in the training-sample and 50%(35/70) in the test-sample. Highest DLM training accuracy was 85.37%(loss=0.3766) at epoch 15/50 with 79.30%(loss=0.3766) comparative validation accuracy, demonstrating strong discriminative ability in model classification between symptomatic and asymptomatic patients. Lower accuracy due to model overfitting was observed after 50 epochs.

Conclusions

Image-based DLMs using standard, preoperative CT images very successfully predicted 1-year AWR QOL. The impact of DLMs on preoperative counseling/consent for surgery could be revolutionary.

V-014 OPEN REPAIR OF PRIMARY LUMBAR HERNIA WITH PREPERITONEAL MESH

This video presents an open repair of a primary lumbar hernia with preperitoneal mesh performed at a high-volume hernia center. The patient was a 71-year-old female referred due to chronic pain from a primary hernia of the right superior lumbar triangle.

The patient was positioned in the left lateral decubitus position with the bed slightly flexed. A skin incision was created sharply, and electrocautery used to dissect subcutaneous tissue and superficial fascia, revealing the hernia contents.

Circumferential lysis of adhesions was performed with blunt and cautery dissection to release the hernia contents from the abdominal wall. Once the hernia contents were mobilized, they were then carefully reduced through the fascial defect. The hernia defect measured approximately 3.5×3.5 cm.

Next, the preperitoneal space was circumferentially developed. This was done primarily with blunt finger dissection, using a rolling motion to direct pressure towards the abdominal wall and sweep the peritoneum and other attachments down. Larger attachments are gently retracted and divided with electrocautery. The preperitoneal space was measured at 20×19 cm and the mesh trimmed to those dimensions. The mesh was carefully laid flat in the preperitoneal space. No mesh fixation was required.

Fascial edges were dissected free for 1–2cm surrounding the defect. Two running 1–0 PDS sutures were used to close the hernia defect. A closed-suction drain was placed superficial to the fascia to minimize seroma formation. The superficial fascia and dermis were closed in layers. The patient had a routine hospital course and was discharged on post-operative day 3.