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.

Surgical treatment of traumatic eventration with polyester button and polypropylene mesh to strengthen the suture technique in equine.

BACKGROUND: Defects in the abdominal wall of horses have high relapse rate. This is mainly in lateral eventrations and hernias caused by trauma from kicks of other horses or installation structures. The eventration region normally becomes swollen and there may be complications due to intestinal loop incarceration. The surgical treatment, consisting of reconstruction of the abdominal wall, frequently require biological or synthetic materials for the reinforcement of the suture line and tension support. Therefore, several studies have reported new materials for the repair of the abdominal wall, with the aim of improving the integration among adjacent tissues and reducing risks and complications such as rejection and infection. This report describes for the first time the use of a regular polypropylene mesh reinforced with polyester buttons for the herniorrhaphy. CASE PRESENTATION: A male, three-year-old, Appaloosa with 500 Kg presented to our hospital with a 10 days history of an increased volume on the left ventro-lateral region of the abdomen. During the physical examination, a deventration following traumatic rupture of the abdominal wall was diagnosed via ultrasonography. Then, the equine was anesthetized and moved to surgery for correction of the eventration which was performed according to conventional technique described in literature. Two days later, an eventration relapse was observed and confirmed via ultrasonography. After that, a second surgical intervention was performed using polyester buttons and polypropylene mesh. After the second surgical procedure, no complications related to eventration were observed either intra or postoperatively. After that, a recheck was performed thirty days later where satisfactory wound healing and total recovery were observed. CONCLUSION: The use of polypropylene mesh reinforced with polyester buttons is an effective technique for the repair of traumatic eventration in horses. This technique provides effective reinforcement against the abdominal tension and was a good option for reconstruction of lacerated muscles in cases of equine post-traumatic eventration, including relapsing cases.

Endometriosis-associated clear cell carcinoma arising in caesarean section scar: a case report and review of the literature.

BACKGROUND: Malignant transformation has been reported in approximately 1% of the endometriosis cases; herein, we report a case of clear cell endometrial carcinoma arising from endometriosis foci located within a caesarean section scar. CASE PRESENTATION: In November 2014, a Caucasian, 44-year-old woman was transferred to our institution because of severe respiratory failure due to massive lung embolism and rapid enlargement of a subcutaneous suprapubic mass. Abdomino-pelvic magnetic resonance showed a 10.5 × 5.0 × 5.0 cm subcutaneous solid mass involving the rectus abdominis muscle. Pelvic organs appeared normal, while right external iliac lymph nodes appeared enlarged (maximum diameter = 16 mm). A whole-body positron emission tomography/computed tomography scan showed irregular uptake of the radiotracer in the 22 cm mass of the abdominal wall, and in enlarged external iliac and inguinal lymph nodes. In December 2014, the patient underwent exploratory laparoscopy showing normal adnexae and pelvic organs; peritoneal as well as cervical, endometrial and vesical biopsies were negative. The patient was administered neo-adjuvant chemotherapy with carboplatin and paclitaxel, weekly, without benefit and then underwent wide resection of the abdominal mass, partial removal of rectus abdominis muscle and fascia, radical hysterectomy, bilateral salpingo-oophorectomy, and inguinal and pelvic lymphadenectomy. The muscular gap was repaired employing a gore-tex mesh while the external covering was made by a pedicled perforator fasciocutaneous anterolateral thigh flap. Final diagnosis was clear cell endometrial adenocarcinoma arising from endometriosis foci within the caesarean section scar. Pelvic and inguinal lymph nodes were metastatic. Tumor cells were positive for CK7 EMA, CKAE1/AE3, CD15, CA-125, while immunoreaction for Calretinin, WT1, estrogen, and progesterone receptors, cytokeratin 20, CD10, alpha fetoprotein, CDX2, TTF1, and thyroglobulin were all negative. Liver relapse occurred after 2 months; despite 3 cycles of pegylated liposomal doxorubicin (20 mg/m2, biweekly administration), the death of the patient disease occurred 1 month later. CONCLUSIONS: Attention should be focused on careful evaluation of patient history in terms of pelvic surgery, and symptoms suggestive of endometriosis such as repeated occurrence of endometriosis nodules at CS scar, or cyclic pain, or volume changes of the nodules.

[Indications and results of preventive endoprosthezing of the abdominal wall during operations on organs of the abdominal cavity and retroperitoneal space].

Complex examination and treatment of 120 patients with anatomo-functional insufficiency of the abdominal wall was made after operations on organs of the abdominal cavity and retroperitoneal space. In the 1st group (60 patients) the abdominal wall was sutured by traditional methods. In the 2nd group (60 patients) laparotomy was followed by implantation of polypropylene endoprosthesis by over-aponeurotic method, and suturing of the lateral wall--by sub-aponeurotic method. At the long-term postoperative period the postoperative ventral hernias were formed in 21.6% of patients of the 1st group, in the 2nd group of patients hernias were not detected. Physical component of quality of life of the 2nd group was 1.5 times, and mental component 1.7 times higher than in the 1st group.

The worst-case scenario: Bridging repair with a biologic mesh in high-risk patients with very large abdominal wall hernias-a prospective multicenter study.

BACKGROUND: While modern techniques allow midline fascial closure for most abdominal hernias, a bridge repair with mesh may be the only alternative in very large defects. When the risk of infection is high, the use of prosthetic mesh is controversial. We aim to examine outcomes after bridge repair of very large abdominal hernias at high risk for postoperative infection with a second-generation biologic mesh. METHODS: Prospective, multicenter, single-arm study of patients with very large abdominal hernias who received bridge repair with a neonatal bovine dermis mesh. Primary outcome was hernia recurrence, as identified on computed tomography 1 year after the operation. Secondary outcomes included mesh laxity, surgical site occurrences, and any other mesh-related complications. Independent risk factors of the outcomes were determined by univariate and multivariable analyses. RESULTS: A total of 117 bridge repair patients were enrolled with a mean defect size of 442.5 ± 254.2 cm2. The patients were predominantly obese (mean body mass index 36.5 ± 10.5) and with multiple comorbidities (Charlson comorbidity index 3 ± 2.5). Hernia recurrence was identified in 24 (20.5%) patients. An infected mesh at the index operation was an independent predictor of hernia recurrence, whereas obesity was an independent predictor of the pooled endpoint of recurrence and mesh laxity. Surgical site occurrences were recorded in 36.8% of the patients, and no independent risk factors were identified. CONCLUSION: In patients with very large abdominal hernias and at high risk for postoperative infection, who cannot undergo midline fascial closure, a bridge repair with neonatal bovine dermis mesh offers an acceptable profile in terms of hernia recurrence and wound occurrences.

The use of synthetic mesh in contaminated and infected abdominal wall repairs: challenging the dogma-A long-term prospective clinical trial.

BACKGROUND: Abdominal wall reconstruction in patients presenting with enteric fistulas and mesh infection is challenging. There is a consensus that synthetic mesh must be avoided in infected operations, and the alternatives to using synthetic mesh, such as component separation techniques and biologic mesh, present disappointing results with expressive wound infection and hernia recurrence rates. METHODS: A prospective clinical trial designed to evaluate the short- and long-term outcomes of 40 patients submitted to elective abdominal wall repair with synthetic mesh in the dirty-infected setting, and compared to a cohort of 40 patients submitted to clean ventral hernia repairs. Patients in both groups were submitted to a single-staged repair using onlay polypropylene mesh reinforcement. RESULTS: Groups' characteristics were similar. There were 13 (32.5%) surgical site occurrences in the infected mesh (IM) group, compared to 11 (27.5%) in the clean-control (CC) group, p = 0.626. The 30-day surgical site infection rate was 15% for the IM group vs. 10% for the CC cases, p = 0.499. One patient required a complete mesh removal in each group. The mean overall follow-up was 50.2 ± 14.8 months, with 36 patients in the IM group and 38 clean-controls completing a follow-up of 36 months. There was one hernia recurrence (4.2%) in the IM group and no recurrences in the CC group. CONCLUSION: We demonstrated that using polypropylene mesh in the infected setting presented similar outcomes to clean repairs. The use of synthetic mesh in the onlay position resulted in a safe and durable abdominal wall reconstruction. TRIAL REGISTRATION: Study registered at Plataforma Brasil (plataformabrasil.saude.gov.br), CAAE 30836614.7.0000.0068. Study registered at Clinical Trials (clinicaltrials.gov), Identifier NCT03702153.

Application of a novel material in the inguinal region using a totally percutaneous approach in an animal model: a new potential technique?

PURPOSE: To evaluate the feasibility and safety of a new percutaneous image-guided surgery technique to simulate a hernia repair using hydrogel. MATERIALS AND METHODS: A comparative prospective study was conducted in animals, with survival. Five pigs without any hernias were used. A hydrogel was injected at a site corresponding to the preperitoneal inguinal region. This procedure was performed bilaterally. An image-guided needle (ultrasound and computed tomography) was used, through which the material was injected. After survival, the local and systemic inflammatory reaction generated by the new material, was studied. RESULTS: All animals survived the procedure. No hemorrhagic or infectious complications were reported. The solidification of the material occurred as expected. In eight out of ten cases, the material was found in the planned site. No systemic inflammatory reaction secondary to the administration of hydrogel was reported. The adhesion of the material to surrounding tissues was satisfactory. CONCLUSION: The introduction of a liquid material which solidifies after injection in a short time (hydrogel) using a needle is feasible. The combined CT-scan and US image guidance allows for the percutaneous placement of the needle in the required location. The introduced hydrogel remains in this space, corresponding to the inguinal region, without moving. The placed hydrogel compresses the posterior wall composed of the transversalis fascia, supporting the potential use of hydrogel for hernia defects.

Effects of abdominal binding on cardiorespiratory function in cervical spinal cord injury.

We asked whether abdominal binding improves cardiorespiratory function in individuals with cervical spinal cord injury (SCI). 13 participants with chronic SCI (C(5)-C(7)) and 8 able-bodied controls were exposed to varying degrees of elastic abdominal compression (unbound [UB], loose-bound [LB], and tight-bound [TB]) while seated. In SCI, TB increased vital capacity (14%), expiratory flow throughout vital capacity (15%), inspiratory capacity (21%), and maximal expiratory mouth pressure (25%). In contrast, TB reduced residual volume (-34%) and functional residual capacity (-23%). TB increased tidal and twitch transdiaphragmatic pressures (∼45%), primarily by increasing the gastric pressure contributions. TB increased cardiac output (28%), systolic mitral annular velocity (22%), and late-diastolic mitral annular velocity (50%). Selected measures of cardiorespiratory function improved with LB, but the changes were less compared to TB. In able-bodied, changes were inconsistent and always less than in SCI. In conclusion, abdominal-binding improved cardiorespiratory function in low-cervical SCI by optimising operating lung volumes, increasing expiratory flow, enhancing diaphragmatic pressure production, and improving left-ventricular function.