Evaluation of forces applied to tissues during robotic-assisted surgical tasks using a novel force feedback technology.

BACKGROUND: The absence of force feedback (FFB) is considered a technical limitation in robotic-assisted surgery (RAS). This pre-clinical study aims to evaluate the forces applied to tissues using a novel integrated FFB technology, which allows surgeons to sense forces exerted at the instrument tips. METHODS: Twenty-eight surgeons with varying experience levels employed FFB instruments to perform three robotic-assisted surgical tasks, including retraction, dissection, and suturing, on inanimate or ex-vivo models, while the instrument sensors recorded and conveyed the applied forces to the surgeon hand controllers of the robotic system. Generalized Estimating Equations (GEE) models were used to analyze the mean and maximal forces applied during each task with the FFB sensor at the "Off" setting compared to the "High" sensitivity setting for retraction and to the "Low", "Medium", and "High" sensitivity settings for dissection and suturing. Sub-analysis was also performed on surgeon experience levels. RESULTS: The use of FFB at any of the sensitivity settings resulted in a significant reduction in both the mean and maximal forces exerted on tissue during all three robotic-assisted surgical tasks (p < 0.0001). The maximal force exerted, potentially associated with tissue damage, was decreased by 36%, 41%, and 55% with the use of FFB at the "High" sensitivity setting while performing retraction, dissection, and interrupted suturing tasks, respectively. Further, the use of FFB resulted in substantial reductions in force variance during the performance of all three types of tasks. In general, reductions in mean and maximal forces were observed among surgeons at all experience levels. The degree of force reduction depends on the sensitivity setting selected and the types of surgical tasks evaluated. CONCLUSIONS: Our findings demonstrate that the utilization of FFB technology integrated in the robotic surgical system significantly reduced the forces exerted on tissue during the performance of surgical tasks at all surgeon experience levels. The reduction in the force applied and a consistency of force application achieved with FFB use, could result in decreases in tissue trauma and blood loss, potentially leading to better clinical outcomes in patients undergoing RAS. Future studies will be important to determine the impact of FFB instruments in a live clinical environment.

A prospective, multicenter trial of a long-term bioabsorbable mesh with Sepra technology in cohort of challenging laparoscopic ventral or incisional hernia repairs (ATLAS trial).

BACKGROUND: This prospective, multicenter, single-arm, open-label study evaluated P4HB-ST mesh in laparoscopic ventral or incisional hernia repair (LVIHR) in patients with Class I (clean) wounds at high risk for Surgical Site Occurrence (SSO). METHODS: Primary endpoint was SSO requiring intervention <45 days. Secondary endpoints included: surgical procedure time, length of stay, SSO >45 days, hernia recurrence, device-related adverse events, reoperation, and Quality of Life at 1, 3, 6, 12, 18, and 24-months. RESULTS: 120 patients (52.5% male), mean age of 55.0 ± 14.9 years, and BMI of 33.2 ± 4.5 kg/m2 received P4HB-ST mesh. Patient-reported comorbid conditions included: obesity (86.7%), active smoker (45.0%), COPD (5.0%), diabetes (16.7%), immunosuppression (2.5%), coronary artery disease (7.5%), chronic corticosteroid use (2.5%), hypoalbuminemia (0.8%), advanced age (10.0%), and renal insufficiency (0.8%). Hernia types were primary ventral (44.2%), primary incisional (37.5%), recurrent ventral (5.8%), and recurrent incisional (12.5%). Patients underwent LVIHR in laparoscopic (55.8%) or robotic-assisted cases (44.2%), mean defect size 15.7 ± 28.3 cm2, mean procedure time 85.9 ± 43.0 min, and mean length of stay 1.0 ± 1.4 days. There were no SSOs requiring intervention beyond 45 days, n = 38 (31.7%) recurrences, n = 22 (18.3%) reoperations, and n = 2 (1.7%) device-related adverse events (excluding recurrence). CONCLUSION: P4HB-ST mesh demonstrated low rates of SSO and device-related complications, with improved quality of life scores, and reoperation rate comparable to other published studies. Recurrence rate was higher than expected at 31.7%. However, when analyzed by hernia defect size, recurrence was disproportionately high in defects ≥7.1 cm2 (43.3%) compared to defects <7.1 cm2 (18.6%). Thus, in LVIHR, P4HB-ST may be better suited for small defects. Caution is warranted when utilizing P4HB-ST in laparoscopic IPOM repair of larger defects until additional studies can further investigate outcomes.

Does immunosuppression increase perioperative wound morbidity in patients undergoing transversus abdominis release?

BACKGROUND: Transversus abdominis release is an effective procedure for complex ventral hernias. As wound complications contribute to hernia recurrences, mitigating risk factors is vitally important for hernia surgeons. Although immunosuppression can impair wound healing, it has inconsistently predicted wound occurrences, and its effect on wound morbidity after a transversus abdominis release is unknown. METHODS: Patients undergoing either an elective open or robotic bilateral transversus abdominis release with permanent synthetic mesh were retrospectively stratified by perioperative immunosuppression and secondarily by procedure type (open versus robotic) and immunosuppression. RESULTS: A total of 321 patients were included for analysis. Overall, 63 (19.6%) patients were on chronic immunosuppression, with history of solid-organ transplant being the most common indication (43 patients). Patients stratified by perioperative immunosuppression were well-matched with similar defect size (P = .97), body mass index ≥30 (P = .32), diabetes (P = .09), history of surgical site infection (P = .53), surgical approach (P = .53), and tobacco use history (P = .33). No differences between cohorts were elicited for any wound event when stratified by immunosuppression use. Similarly, no differences were elicited when cohorts were further stratified also by procedure type. CONCLUSION: Chronic immunosuppression is often viewed as a notable risk factor for wound occurrences after surgery. However, our data suggest immunosuppression may not significantly increase the risk of perioperative wound morbidity follow transversus abdominis release as previously predicted.

Transversus abdominis release with posterior component separation in patients with previously recurrent ventral hernias: A single institution experience.

BACKGROUND: Recurrent hernias pose significant challenges due to violated anatomic planes, resultant scar, and potential prior mesh. Transversus abdominis release has been widely utilized for complex hernias. Transversus abdominis release can provide a novel plane for dissection and mesh placement for recurrent hernias. This study provides our institution's experience with transversus abdominis release in patients with recurrent ventral hernias. METHODS: A retrospective chart review was conducted of patients with recurrent ventral hernias from January 2018 to September 2020 who underwent transversus abdominis release by 2 fellowship-trained abdominal wall surgeons. Combined procedures (ie, gynecological/urological), robotic totally extraperitoneal, and emergency cases were excluded. Demographics, perioperative, and postoperative outcomes were reviewed. RESULTS: In total, 108 patients underwent open-transversus abdominis release and 25 had robotic-transversus abdominis release for recurrent ventral hernias. All patients received a lightweight to midweight nonabsorbable polypropylene synthetic mesh. Mean age was 59, mean body mass index was 34 kg/m2, with mean hernia defect area of 333 cm2. We noted 34 (25.6%) surgical site occurrences and 11 (8.3%) surgical site infections. Mean postoperative follow-up was 15.5 months, with 7 (5%) recurrences (6 open-transversus abdominis release, 1 robotic-transversus abdominis release). A minimum 12-month follow-up was available for 62% of patients, and minimum 6-month follow-up in 80% of patients. CONCLUSION: Recurrent hernias pose significant operative challenges for surgeons due to violated tissue planes and limited repair options. Our experience suggests that transversus abdominis release may provide a durable repair for difficult recurrent ventral hernias. However, long-term postoperative follow-up over multiple years is still needed to establish extended durability of transversus abdominis release in these patients.

Evaluation of information on the Internet regarding surgical mesh for hernia repair: analysis of websites found through three popular search engines.

PURPOSE: Hernia repair remains one of the most common surgical procedures. Surgical mesh usage has been highlighted in the media due to recent lawsuits and recalls. Patients can read potentially biased information on the Internet and this can influence a patient's healthcare decisions. The purpose of this study is to evaluate search engine listings and respective website content of surgical mesh for hernia repair. METHODS: Websites evaluated were derived from four keyword searches targeting surgical mesh with Google, Yahoo, and Bing. Websites from the first two pages of each search were evaluated for content comprehensiveness. RESULTS: The largest category of websites from search engine results was legal advertisements, accounting for 20% of all results. These websites also held the first position on every results page. Legal advertisements and blog/forum websites were the most skewed toward surgical mesh risks and complications vs. benefits. There was a reduction in advertisements in 2020 vs. 2018. The most comprehensive non-advertisement websites were found more frequently. Overall, only 44% of websites presented references and 50% cited supporting data. Finally, 46% of 'recommended search terms' displayed on the search engine results page had a risk, complication, or legal bias. CONCLUSIONS: These results emphasize the challenges of using an Internet search engine to find comprehensive and appropriate information regarding surgical mesh. This manuscript underscores the importance for physicians to direct patients toward specific websites to mitigate their exposure to websites that are biased and not appropriate for patients searching for an accurate and comprehensive overview of surgical mesh.

Initial Experience with a Virtual Platform for Advanced Gastrointestinal Minimally Invasive Surgery Fellowship Interviews.

BACKGROUND: The COVID-19 pandemic travel restrictions triggered a rapid alteration in the interview process for fellowships this spring. We describe our initial experience with virtual interviews for Advanced Gastrointestinal (GI) Minimally Invasive Surgery Fellowships and assess the value and limitations via a post-interview applicant survey. STUDY DESIGN: Twenty candidates were interviewed via Zoom teleconferencing during March and April 2020 using combined group and breakout rooms. An anonymous post-interview Likert and free text survey was sent to candidates with questions regarding feasibility, appropriateness, and acceptability of this method. RESULTS: Seventeen of 20 candidates (85%) responded to the survey. The candidates rated ease of interaction with the program director, faculty surgeons, and the current fellow highly: 94%, 83%, and 89%, respectively. The majority (53%) stated the virtual interviews exceeded or met expectations. Only a minority, 12%, reported the virtual platform was short of expectations. Approximately 70% noted little to no impact of not being able to conduct these interviews in-person and not being able to physically see the program institution. Overall, 94% were satisfied with their experience, and only 6% were neutral, with no respondents reporting dissatisfaction. Finally, 76% would recommend a virtual interview in the future. Most negative open response comments were secondary to issues with software rather than the lack of the in-person traditional interviews. CONCLUSIONS: The use of a remote teleconferencing platform provides a favorable method for conducting fellowship interviews and results in a high degree of candidate satisfaction. Virtual interviews will likely be increasingly substituted for in-person interviews across the spectrum of medical training.

The impact of internet-based patient self-education of surgical mesh on patient attitudes and healthcare decisions prior to hernia surgery.

BACKGROUND: As internet access improves, patient self-education continues to increase. However, patient surgical background, e-literacy, and media exposure potentially influence what information patients search online. This impacts patient concern, healthcare decisions, and subsequent patient-physician interactions. The purpose of this pilot study is to characterize hernia patients' use and the impact of internet self-education regarding surgical mesh. METHODS: The target population included patients presenting for evaluation of hernia repair with mesh. A total of 30 patients were enrolled. Patients took surveys before and after the initial surgical consult. The surveys evaluated internet use, mesh research completed, the impact on patient opinions/decisions, and the impact of research on the patient-physician interaction. RESULTS: The average age of the patients was 58.7 years; sixteen had prior surgery with surgical mesh. 93% of patients were aware of surgical mesh through the media, and 60% were motivated by the media to conduct research. 90% of patients conducted research, and 67% used the internet. Patients with negative attitudes toward mesh had more media exposure in comparison to those with neutral or positive attitudes (p = 0.046), and they were more likely to have researched surgical mesh because of media influence (p = 0.033). This group had the highest rate of perceived knowledge on mesh risks and the lowest regarding benefits (p = 0.013). Patients who had prior surgery without complication had the most positive attitude toward surgical mesh (p = 0.010) and were less likely to plan to do future internet research (p = 0.041) in comparison to patients who had surgery with complications or no prior surgery. CONCLUSIONS: Patients' attitudes and perceived knowledge regarding surgical mesh are associated with media exposure and internet research. These attributes along with prior surgical experience impact the patient-physician relationship and shared decision-making model regarding patient care.

Controversies and Techniques in the Repair of Abdominal Wall Hernias.

Abdominal wall hernia repair is one of the most common operations done by general surgeons today. Patients with incisional hernias can be extremely challenging to manage due to a number of factors that include obesity, prior hernia repairs, previous mesh placement, loss of domain, and other variables. The approach to patients with incisional hernias has evolved considerably over the last 20 years due to both advances in mesh technology and surgical approaches. Key factors in a successful outcome include modification of risk factors prior to surgery such as smoking cessation and weight reduction, selection of mesh appropriate to the hernia type and planned location of the mesh, and broad overlap of mesh beyond the margins of the hernia defect. Newer techniques such as transabdominis release and component separation with retrorectus mesh placement and robotic approaches to abdominal wall hernia are being increasingly utilized in these patients. This article reviews these aspects of abdominal wall hernia repair with a discussion of recent results and the importance of quality improvement and monitoring of outcomes.

Postoperative opioid prescribing practices and the impact of the hydrocodone schedule change.

BACKGROUND: In 2014, hydrocodone was moved from Schedule III to II, thus it could no longer be "called in" to a pharmacy. We analyzed current postoperative opioid prescribing patterns and the impact of the schedule change on the type and amount prescribed. METHODS: Opioid prescriptions for common surgeries at 1 medical center from 2013 to 2016 were analyzed retrospectively. Milligram morphine equivalents prescribed before and after the schedule change were compared by t tests, and interrupted time series models and drug frequencies were compared by χ2 and Fisher exact tests. RESULTS: Data from 7,046 patients (7,361 prescriptions) after 29 different operations were analyzed. Milligram morphine equivalents prescribed for minor open procedures ranged from 211 to 342 milligram morphine equivalents, from 323 to 1297 for major open procedures, from 238 to 359 for basic laparoscopic procedures, and from 221 to 868 for complex laparoscopic procedures. Mean milligram morphine equivalents prescribed were not affected for most procedures, but over the entire population, milligram morphine equivalents prescribed began decreasing after the rule change. The percentage of hydrocodone prescriptions decreased after the rule change (from 33.8% down to 27.0%) and oxycodone and tramadol prescriptions increased. CONCLUSION: Before versus after the rule change, hydrocodone prescriptions decreased and oxycodone and tramadol prescriptions increased. Milligram morphine equivalents prescribed varied considerably across and within classes of procedures, but the schedule change did not affect mean milligram morphine equivalents prescribed for most procedures.

Opioid Medication Use in the Surgical Patient: An Assessment of Prescribing Patterns and Use.

BACKGROUND: With the epidemic of prescription opioid abuse in the US, rates of opioid-related unintentional deaths have risen dramatically. However, few data exist comparing postoperative opioid prescriptions with patient use. We sought to better elucidate this relationship in surgical patients. STUDY DESIGN: A prospective cohort study was conducted of narcotic-naïve patients undergoing open and laparoscopic abdominal procedures on a minimally invasive surgery service. During the first 14 post-discharge days and at their first postoperative clinic visit, patients recorded pain scores and number of opioid pills taken. Clinical data were extracted from the medical record. Descriptive statistics were used in data analysis. RESULTS: From 2014 through 2017, one hundred and seventy-six patients completed postoperative pain surveys. Mean age was 60.4 ± 14.9 years and sex was distributed equally. Most patients (69.9%) underwent laparoscopic procedures. Hydrocodone-acetaminophen was the most commonly prescribed postoperative pain medication (118 patients [67.0%]), followed by oxycodone-acetaminophen (26 patients [14.8%]). Patients were prescribed a median of 150 morphine milligram equivalents (MME) (interquartile range [IQR] 150 to 225 MME), equivalent to twenty 5-mg oral oxycodone pills (IQR 20 to 30 pills). However, by their first postoperative visit, they had only taken a median 30 MME (IQR 10 to 90 MME), or 4 pills (IQR 1.3 to 12 pills). Eight (4.5%) patients received a refill or an additional prescription for pain medications. At the first postoperative visit, 76.7% of respondents were satisfied or very satisfied with their overall postoperative pain management. CONCLUSIONS: Postoperative patients might consume less than half of the opioid pills they are prescribed. More research is needed to standardize opioid prescriptions for postoperative pain management while reducing opioid diversion.

Combined in vivo and ex vivo analysis of mesh mechanics in a porcine hernia model.

BACKGROUND: Hernia meshes exhibit variability in mechanical properties, and their mechanical match to tissue has not been comprehensively studied. We used an innovative imaging model of in vivo strain tracking and ex vivo mechanical analysis to assess effects of mesh properties on repaired abdominal walls in a porcine model. We hypothesized that meshes with dissimilar mechanical properties compared to native tissue would alter abdominal wall mechanics more than better-matched meshes. METHODS: Seven mini-pigs underwent ventral hernia creation and subsequent open repair with one of two heavyweight polypropylene meshes. Following mesh implantation with attached radio-opaque beads, fluoroscopic images were taken at insufflation pressures from 5 to 30 mmHg on postoperative days 0, 7, and 28. At 28 days, animals were euthanized and ex vivo mechanical testing performed on full-thickness samples across repaired abdominal walls. Testing was conducted on 13 mini-pig controls, and on meshes separately. Stiffness and anisotropy (the ratio of stiffness in the transverse versus craniocaudal directions) were assessed. RESULTS: 3D reconstructions of repaired abdominal walls showed stretch patterns. As pressure increased, both meshes expanded, with no differences between groups. Over time, meshes contracted 17.65% (Mesh A) and 0.12% (Mesh B; p = 0.06). Mesh mechanics showed that Mesh A deviated from anisotropic native tissue more than Mesh B. Compared to native tissue, Mesh A was stiffer both transversely and craniocaudally. Explanted repaired abdominal walls of both treatment groups were stiffer than native tissue. Repaired tissue became less anisotropic over time, as mesh properties prevailed over native abdominal wall properties. CONCLUSIONS: This technique assessed 3D stretch at the mesh level in vivo in a porcine model. While the abdominal wall expanded, mesh-ingrown areas contracted, potentially indicating stresses at mesh edges. Ex vivo mechanics demonstrate that repaired tissue adopts mesh properties, suggesting that a better-matched mesh could reduce changes to abdominal wall mechanics.

Critical Under-Reporting of Hernia Mesh Properties and Development of a Novel Package Label.

BACKGROUND: With an array of hernia meshes with varying properties, intraoperative decision making for the optimal mesh is critical. Although meshes are subjected to regulatory review through the Food and Drug Administration, it is unknown whether mesh properties are visually accessible. To facilitate greater knowledge for the surgeon on mesh choice, we aimed to comprehensively analyze hernia mesh packaging and regulations. STUDY DESIGN: Labeling guidelines and 510(k) requirements across Food and Drug Administration-regulated products were analyzed and compared with mesh packaging. Packages and Instructions for Use were analyzed for commonly available hernia meshes. Literature review was conducted to understand recommended guidelines for mesh products. A novel hernia mesh packaging label was designed to rectify under-reporting. RESULTS: We found that food labels undergo critical scrutiny and detailed specifications, yet medical devices are not subjected to similar guidelines. The highest reported property on packages was the presence of a barrier (80%), and the lowest reported property was barrier composition (33%). For Instructions for Use, the lowest reported properties were mechanics (31%) and thickness (11%), both of which were not reported on packaging. Descriptive terms for pore size and mechanics were reported inconsistently. To overcome this under-reporting of properties, we propose a novel packaging label with properties chosen from regulatory guidelines, packaging analysis, and literature review. CONCLUSIONS: Although standardized terminology has been proposed in literature, property knowledge has not adequately permeated surgery, industry, or regulatory guidelines. There is extreme under-reporting and lack of consistency of clinically important mesh properties. Standardized packaging labels will provide accessibility of these properties and aim to bring standardized terminology into practice. With an increase in access to important properties, this can facilitate intraoperative decision making on a case-by-case basis.

Multi-directional mechanical analysis of synthetic scaffolds for hernia repair.

Hernias remain one of the most common ailments to affect men and women worldwide. Surgical mesh materials were first used to reinforce hernia defects during surgery in the late 1950s (Laker, n.d.). Today, there are well over 50 prosthetic meshes available for hernia repair (Brown and Finch, 2010; Bryan et al., 2014; Hope and El-hayek, 2014). With the multitude of available options, surgeons are faced with the challenging task of optimizing mesh selection for each patient. If the mechanics of the mesh are not compatible with the surrounding tissue, mismatch can occur, which can lead to complications such as mesh failure and/or hernia recurrence. Unfortunately, many aspects of synthetic mesh mechanics remain poorly described. Therefore, the purpose of this study was to provide a more complete mechanical analysis of a variety of commercially available prosthetic meshes for hernia repair, including evaluation of meshes in a variety of orientations. Twenty different meshes were subjected to biaxial tensile tests at both 90° and 45° orientations, and results were analyzed for relative strength, strain behavior, and anisotropy. Peak tension and strain values varied dramatically across all mesh types for all directions, ranging between 4.08 and 25.74N/cm and -5% to 10% strain. Anisotropy ratios for the evaluated meshes ranged from 0.33 to 1.89, demonstrating a wide range in relative direction-dependence of mesh mechanics. While further study of prosthetic meshes and better characterization of properties of the human abdominal wall are needed, results of this study provide valuable data that may aid clinicians in optimizing mesh selection for specific patients and repair conditions.

Suture choice matters in rabbit model of laparoscopic, preperitoneal, inguinal hernia repair.

PURPOSE: We evaluated the effect of different suture materials in a laparoscopic preperitoneal ligation of the patent processus vaginalis in a rabbit survival model. MATERIALS AND METHODS: New Zealand White rabbits underwent laparoscopic assisted preperitoneal ligation of the patent processus vaginalis. The processus vaginalis was closed with silk (n=10), polyglactin 910 (Vicryl(®); Ethicon, a Johnson & Johnson Company, Somerville, NJ) (n=10), or polypropylene (Prolene(®); Ethicon) (n=10). At necropsy, the suture was removed, and repair integrity was evaluated. RESULTS: All rabbits survived to necropsy without complications. No suture material was identified during necropsy of the Vicryl group. Eight (80%) of the Vicryl closures failed, with six (60%) failing at initial inspection. Following removal of suture material, nine (90%) of the Prolene closures failed, and only one (10%) of the silk closures failed (P=.009). CONCLUSIONS: The silk suture resulted in an improved closure rate. Ligation with silk suture probably incited an increased inflammatory response that likely created a scar while persisting long enough for the scar to become established. In contrast, the Vicryl sutures probably failed because the sutures dissolved before a scar was able to fully develop. Finally, the Prolene closures were suture dependent as evidenced by failure when the suture was removed. Nonabsorbable braided suture may improve closure of pediatric indirect inguinal hernias during laparoscopic-assisted preperitoneal ligation.

Methodology of fibroblast and mesenchymal stem cell coating of surgical meshes: a pilot analysis.

Coating of various synthetic, absorbable, and biologic meshes with mesenchymal stem cells (MSCs) and fibroblasts was analyzed qualitatively and quantitatively. Five hernia meshes-light weight monofilament polypropylene (Soft Mesh), polyester (Parietex-TET), polylactide composite (TIGR), heavy weight monofilament polypropylene (Marlex), and porcine dermal collagen (Strattice)-were coated with three cell lines: human dermal fibroblasts (HFs), rat kidney fibroblasts (NRKs), and rat MSCs. Cell densities were determined at different time points. Samples also underwent histology and transmission electron microscopic (TEM) analyses. It required HFs 3 weeks to cover the entire mesh, while only 2 weeks for NRKs and MSCs to do so. MSCs had no preference for any of the meshes and produced the highest cell densities on Parietex and TIGR. Substrate-preference accounted for the significantly lower fibroblast densities on TIGR than Parietex. Fibroblasts failed to coat Marlex. Strattice, which had the least surface area, generated comparable cell densities to Parietex. Both histology and TEM confirmed cell coating of mesh surface. Various prosthetics can be coated by certain cell strains. Both mesh composition and cell preference dramatically influence the coating process. This methodology provides foundation for novel avenues of modulation of host response to various modern synthetic and biologic meshes.

A 5-year clinical experience with single-staged repairs of infected and contaminated abdominal wall defects utilizing biologic mesh.

OBJECTIVE: Our objective was to evaluate the safety and durability of biologic mesh for single-staged reconstruction of contaminated fields. INTRODUCTION: The presence of contamination during ventral hernia repair (VHR) poses a significant challenge. Some advocate for a multistaged reconstructive approach with delayed definitive repair, whereas others perform definitive repair at the initial operation. METHODS: Patients undergoing single-staged VHR in a contaminated field with biologic mesh over a 5-year period were retrospectively reviewed from a prospectively maintained database. Outcome measures included wound complication and hernia recurrence. RESULTS: A total of 128 patients (76 F, 52 M) were identified, with a mean age of 58.2 years, mean American Society of Anesthesiologist (ASA) score 3.1, and mean body mass index (BMI) 34.1 ± 9.7 kg/m2. Comorbidities included COPD (n = 29), diabetes (n = 65), smoking (n = 29), and immunosuppression (n = 8). Mean hernia defect size was 431 cm2 (range 40-2450 cm2). Reasons for contamination included the presence of infected mesh (n = 45), stoma (n = 24), concomitant gastrointestinal (GI) surgery (n = 17), enterocutaneous fistula (n = 25), open nonhealing wound(s) (n = 6), enterotomy/colotomy (n = 5), and chronic draining sinus (n = 6). Postoperative wound complications were identified in 61 (47.7%) patients. Predictors of wound complications included ASA score, diabetes, smoking, number of previous abdominal surgeries or hernia repairs, hernia defect size, and operative time. With a mean follow-up time of 21.7 months, hernia recurrence was identified in 40 (31.3%) patients. The majority of recurrent hernias were asymptomatic and 7 patients underwent repair. CONCLUSIONS: Despite the high rate of wound morbidity associated with single-staged reconstruction of contaminated fields, it can safely be performed with biologic mesh reinforcement. Although biologic mesh in these situations is safe, the long-term durability seems to be less favorable.

Outcomes of simultaneous large complex abdominal wall reconstruction and enterocutaneous fistula takedown.

BACKGROUND: The surgical management of enterocutaneous fistulas (ECFs) in the setting of large abdominal wall defects can be challenging. We aimed to review our experience with simultaneous single-stage ECF takedown and complex abdominal wall reconstruction (AWR). METHODS: Using a prospectively collected database, patients requiring surgical management of an ECF and AWR over a 5-year period were reviewed. RESULTS: Thirty-seven patients (mean age = 58.6 years) underwent ECF repair/AWR. The mean hernia defect size was 426 ± 192 cm(2). Thirty-five (95%) patients required fascial releases to achieve abdominal wall closure. Thirty-six (97%) patients had sublay biologic mesh placed to reinforce the repair. Twenty-four (65%) patients developed a surgical site infection (8 superficial, 8 deep, and 8 organ space). Four patients developed an early anastomotic leak/refistulization. With a mean follow-up of 20 months, the hernia recurrence rate was 32% (n = 12). CONCLUSIONS: The simultaneous reconstruction of ECF and complex abdominal wall defects resulted in successful single-stage management of these challenging cases in nearly 70% of patients in this series.

Evaluation of high-risk, comorbid patients undergoing open ventral hernia repair with synthetic mesh.

BACKGROUND: The Ventral Hernia Working Group proposed recently a classification system to grade the risk of surgical site occurrence (SSO) during ventral hernia repair (VHR). Accurately predicting the outcomes of synthetic mesh in open VHR for comorbid patients might guide surgeons in appropriate mesh selection in this patient population. Our objective was to determine the incidence of SSO in open, grade II VHR and to examine the use of synthetic mesh in these comorbid patients. METHODS: All open, grade II VHR performed by a single surgeon over a 4-year period were reviewed retrospectively. RESULTS: Eighty-eight patients (43 female; mean age, 57 years) with grade II ventral hernias underwent open VHR with synthetic mesh. Associated comorbidities included obesity in 55 (63%), diabetes mellitus in 43 (49%), chronic obstructive pulmonary disease in 27 (31%), smoking in 21 (24%), and immunosuppression in 18 (21%). The mean number of comorbidities per patient was 1.9 (range, 1-4). SSO occurred in 14 (16%) patients and included infection (n = 11), seroma (n = 2), and wound dehiscence (n = 1). Having multiple comorbidities was associated with an increased risk of SSO (P = .02). Three (3%) patients required reoperation or readmission for wound management. With a mean follow-up of 17.8 months, 4 (5%) patients developed a hernia recurrence. CONCLUSION: Patients with grade II hernias undergoing open VHR are prone to SSO with an incidence of 16%. Although synthetic mesh infections can occur among grade II patients, the majority can be managed conservatively with salvage of the prosthesis, especially if macroporous mesh is used. Given our findings, the use of synthetic mesh in the retrorectus space results in a safe and durable (5% recurrence rate) repair for patients with grade II incisional hernias.

Effect of surgical wound classification on biologic graft performance in complex hernia repair: an experimental study.

BACKGROUND: Despite relatively sparse data regarding their outcomes in the setting of infection, biologic grafts have gained rapid acceptance by the surgical community for complex hernia repair. These materials are heterogeneous in their procurement and processing techniques, which may ultimately have an impact in their ability to withstand infection. The objective of this study is to evaluate the impact of varying levels of contamination on biologic graft performance in a chronic ventral hernia animal model. METHODS: Four commonly applied biologic grafts were used in the repair of a chronic ventral hernia rat model (n = 218). Each material was repaired in the setting of 1 of 4 surgical wound classifications (clean, clean contaminated, contaminated, dirty infected) with Staphylococcus aureus as our inoculum agent. After a 30-day survival, repairs underwent quantitative cultures, histological, and biomechanical testing. RESULTS: Marked differences were observed in biologic graft bacterial burden, biomechanical and histological responses at 30 days. Persistent bacterial burden varied among the biologic grafts and increased with increasing wound contamination (P < .05). Delays in wound healing were observed in the contaminated and dirty infected setting (P < .05). Increasing infection weakened the biomechanical strength of repairs (P < .05). CONCLUSION: The degree of bacterial contamination at the time of repair affected the rates of bacterial clearance, wound-healing ability, and subsequent repair strength. Material source and processing techniques might alter graft durability, biocompatibility, and ability to clear bacteria in a contaminated field. Clinical trials are warranted in contaminated settings.