Pathways of the preperitoneal plane: from the "fatty triangle" in Rives to the "fatty trident" in extended retromuscular abdominal wall reconstruction. A tribute to Prof. Schumpelick.

PURPOSE: Extended retromuscular dissection performed for abdominal wall reconstruction in complex abdominal wall repair has progressively exposed the anatomy between the peritoneal layer and abdominal wall muscles. This study aimed to assess the morphology and distribution of preperitoneal fat in a cadaveric model and its influence in retromuscular preperitoneal dissections. METHODS: Thirty frozen cadaver torsos were dissected by posterior component separation. The shape of the preperitoneal fat was identified, and the dimensions and more significant distances were calculated. RESULTS: The results showed that the preperitoneal fat resembles a trident, exists along the midline under the linea alba, and expands in the epigastric area into a rhomboid shape. The fatty triangle was found to be a part of this rhomboid. Caudally, the midline preperitoneal fat widened under the arcuate line to reach the Retzius space. Laterally, the Bogros space communicated the root of the trident with the paracolic gutters, Toldt's fascia, and pararenal fats, forming the lateral prong of the trident. The peritoneum not covered by the preperitoneal fatty trident was easy to break. Three pathways could be tracked following the distribution of this fat that facilitated the dissection of the preperitoneal space to prepare the landing zone of the meshes in hernia repair. CONCLUSION: The concept of preperitoneal fatty trident may be of practical assistance to perform various hernia procedures, from the simple ventral hernia repair to the more complex preperitoneal ventral repair or posterior component separation techniques. The consistency of this layer allows us to follow three specific pathways to find our plane between the peritoneum and muscle layers to extend the preperitoneal dissection.

Failure of talc seromadesis for the treatment of subcutaneous chronic seromas after incisional hernia surgery.

BACKGROUND AND AIM: Talc poudrage has been used since many years for sclerosing chronic pleural effusion. Several reports have shown good results managing chronic seromas after breast, vascular, and incisional hernia surgeries. The purpose of this study is to determine the utility of talc seromadesis for the management of chronic seromas after incisional hernia surgery. MATERIALS AND METHODS: Multicentric prospective observational study including patients diagnosed of chronic seromas after incisional hernia surgery. Under local anesthesia and ultrasonographic control, two percutaneous trocars were placed in the seroma, washing the seroma cavity with 0.9% saline solution and aspirating the remaining liquid. A sample of 4 g of talcum powder was introduced in the seroma cavity, and a 15-F drain was left in place. Patients were followed each week during at least 4 weeks after drainage removal. RESULTS: Between January 2013 and December 2016, a total of six patients were enrolled in the study. Talc poudrage was performed without any complications. Drains were pulled out in a mean time of 3 (range: 2-4) weeks. One case of the chronic seromas was efficiently sclerosed with talc without recurrence in time. In three cases, the seroma recurred, and the final solution was surgical decortication of the seroma. In the other two cases, seroma also recurred and were managed with instillation of ethanol and iodine povidone. CONCLUSION: In our experience, the management of chronic seromas after incisional hernia repair with talc seromadesis is ineffective and is associated with a high rate of seroma recurrence.

Combining anterior and posterior component separation for extreme cases of abdominal wall reconstruction.

PURPOSE: The closure of midline in abdominal wall incisional hernias is an essential principle. In some exceptional circumstances, despite adequate component separation techniques, this midline closure cannot be achieved. This study aims to review the results of using both anterior and component separation in these exceptional cases. METHODS: We reviewed our experience using the combination of both anterior and posterior component separation in the attempt to close the midline. Our first step was to perform a TAR and a complete extensive dissection of the retromuscular preperitoneal plane developed laterally as far as the posterior axillary line. When the closure of midline was not possible, an external oblique release was made. A retromuscular preperitoneal reinforcement was made with the combination of an absorbable mesh and a 50 × 50 polypropylene mesh. RESULTS: Twelve patients underwent anterior and posterior component separation. The mean hernia width was 23.5 ± 5. The majority were classified as severe complex incisional hernia and had previous attempts of repair. After a mean follow-up of 27 months (range 8-45), no case of recurrence was registered. Only one patient (8.33%) presented with an asymptomatic bulging in the follow-up. European Hernia Society's quality of life scores showed a significant improvement at 2 years postoperatively in the three domains: pain (p = 0.01), restrictions (p = 0.04) and cosmetic (p = 0.01). CONCLUSIONS: The combination of posterior and anterior component separation can effectively treat massive and challenging cases of abdominal wall reconstruction in which the primary midline closure is impossible to achieve despite appropriate optimization of surgery.

Evaluation of a workshop to teach a new surgical technique in abdominal wall reconstruction.

PURPOSE: Assess the utility of a hands-on workshop on abdominal wall reconstruction for teaching the posterior components separation (PCS) with transversus abdominis release. METHODS: Our department has been organizing a training course on abdominal wall reconstruction for the last 6 years. It is a 2-day-long course and 10-12 surgeons with experience in abdominal wall surgery attend to every course. The first day is dedicated to theoretical lectures and two simultaneous live surgeries, and the second day there is a cadaver dissection. Feedback from the trainees was collected at the end of the workshop. A survey was sent to all the surgeons who had completed the course at least a year ago, to inquire how the course had improved their surgical practice. RESULTS: From 2013 to April 2017, we have made 15 editions of the course. A total of 192 surgeons from Europe, South Africa and Middle East attended. All the surgeons answered the survey that was carried out at the end of the course. It showed a very high level of satisfaction in more than 98% of the cases. The second survey was answered by 79 surgeons (41.15%). 96% of the surgeons had modified, after attending the course, their way of dealing with complex abdominal wall problems. Only 29% of the surgeons had made a TAR before attending the course, while 86% are performing it after attending the course and 60% do it on a regular basis. In fact, 43% of surgeons have performed more than five posterior component separations in the last year. CONCLUSIONS: A workshop of abdominal wall surgery that combines live surgery, theoretical content and a cadaver lab can be a very useful tool to expand the use of new surgical techniques.

Long-term outcomes after prophylactic use of onlay mesh in midline laparotomy.

BACKGROUND: The prevalence of incisional hernias (IHs) is still high after midline laparotomy (ML). There is an increasing body of evidence that prophylactic mesh placement (PMP) can be safe and efficient in the short-term outcomes, but there still are some concerns about the potential long-term complications of these meshes. This study describes our long-term PMP experience. METHODS: Observational and prospective study including all patients undergoing the use of prophylactic onlay large-pore polypropylene meshes for the closure of ML since 2008 to 2014. Outcome measures included demographics, perioperative details, wound complications, recurrences, reoperations and chronic complications. RESULTS: A cohort of 172 patients was analysed: 75% elective surgery, 25% emergency cases. Mean age was 68 years with mean body mass index (BMI) of 28.6 kg/m2. Wound classification: 6.4% clean; 85% clean-contaminated; 1.2% contaminated and 8.1% dirty. Follow-up of patients was up to 8 years (mean: 5 ± 1.6). Two meshes were removed due to chronic infection in first six postoperative months. Of the 13 patients (9.02%) who developed IH, 5 of them have been reoperated for IH repair without any difficulty related to previous mesh. During follow-up, 8 patients have been reoperated for other reasons and the integrity of abdominal wall was also checked. After the comparative study, higher BMI and emergency surgery were still risk factors for IH despite PMP. CONCLUSIONS: In our setting, the use of polypropylene prophylactic meshes in MLs is safe, efficient and durable.

Temporary abdominal closure with polytetrafluoroethylene prosthetic mesh in critically ill non-trauma patients.

BACKGROUND: Survival in critically ill non-trauma patients may be improved by performing temporary abdominal closure using different surgical techniques. We describe the use of expanded polytetrafluoroethylene (ePTFE) mesh for temporary abdominal closure in a group of critical patients. We also evaluate definitive abdominal wall closure in these patients once they are in a stable condition. METHOD: We conducted a study of 29 critically ill non-trauma patients who underwent temporary abdominal closure due to sepsis or abdominal compartment syndrome over 7 years at two university hospitals. We analysed factors related to surgical wound type and definitive abdominal wall closure. We evaluated the SAPS 3 severity score and used it to obtain expected mortality. We used the Clavien-Dindo System for Surgical Complications and the Ventral Hernia Working Group Classification during follow-up. RESULTS: Performing temporary abdominal closure with expanded polytetrafluoroethylene mesh was associated with a mortality rate of 20.68%, which was lower than the expected mortality calculated from the SAPS 3 severity score (38.87 ± 21.60). There was no fistula formation related with this type of prosthetic material. In our study group, definitive abdominal wall closure was performed in the 16 patients who survived (69.5%), and six of them underwent this procedure during the original hospital stay. CONCLUSION: Temporary abdominal closure with ePTFE mesh is an effective alternative in some circumstances. We observed a higher survival rate than the predicted figure and there were no cases of enteroatmospheric fistulae using this particular surgical technique. ePTFE facilitates definitive abdominal wall closure, once the patient is in a stable condition.

Searching for the best polypropylene mesh to be used in bowel contamination.

PURPOSE: There is still some concern about the use of polypropylene in case of infection or contamination. The biocompatibility of the recently introduced light-weight polypropylene meshes seems to be promising. This experimental study was designed to evaluate three different weights and pore sizes of polypropylene meshes in a contamination model. METHODS: Thirty rabbits were operated through a pararectal incision. The abdomen, wound and mesh were contaminated with faecal fluid aspirated from the appendix. Groups of ten animals were studied according to three different pore sizes of polypropylene mesh implanted as an inlay technique: very large pore, large pore and medium pore. Five animals of each group were sacrificed on days 21 and 90. Incisional surgical site infection and microbiologic cultures on the 21st and 90th days were the main outcome measures. Tissue integration, shrinkage and biomechanical properties were also tested. RESULTS: Two rabbits died on day 1. There were six incisional surgical site infections (21.4%). Four animals had positive cultures with no macroscopic infection. None of the surviving rabbits with very large pore mesh had clinical infection or positive microbiologic cultures. Very large pore meshes shrank significantly more on day 21. There were no differences in the tensiometric test results. CONCLUSIONS: In our experimental model, low-weight, very large pore polypropylene meshes seem to be the best polypropylene mesh in case of intestinal contamination. These results encourage clinical investigation on the use of low-weight, very large pore polypropylene meshes in the treatment and prevention of hernias in the presence of clean-contaminated or contaminated fields.

Efficacy of hepatocellular carcinoma locoregional therapies on patients waiting for liver transplantation.

The aim of this study was to evaluate the efficacy of different locoregional therapies in patients with HCC on the waiting list for liver transplantation. From October 2001 to July 2003, 13 patients, all men, with HCC diagnosed by cytology, were transplanted at our center. Locoregional therapies were percutaneous ethanol injection (PEI), transcatheter hepatic arterial chemoembolization (TACE), and radiofrequency microwave ablation (RFA). PEI was employed in seven patients, TACE in five (one of them associated with PEI) and RFA in one. Efficacy was evaluated by determining the percentage of tumoral necrosis in the liver explant. Five tumors were T4, four T3, three T2, and one T1. Ten were well differentiated, two moderately differentiated, and one undifferentiated. One patient died due to primary graft malfunction. After a median posttransplant follow-up of 15 months, 12 patients are alive with no sign of tumor recurrence. Most patients with solitary nodules <4 cm who received PEI had 90% to 100% tumor necrosis. Larger tumors had 25% to 30% necrosis. TACE was employed in six patients with large and/or multiple tumors, obtaining 20% to 50% tumor necrosis. RFA was employed in one case obtaining 85% necrosis (tumor of 4 cm). No serious complications occurred with any technique. According to our experience, PEI and RFA are effective locoregional therapies to treat hepatocellular carcinomas of <4 cm in patients on the waiting list. For larger tumors, their association with other techniques, such as TACE, seems adequate.

Adefovir dipivoxil therapy in liver transplant recipients with lamivudine-resistant hepatitis B virus.

Hepatitis B virus (HBV) infection is the leading cause of cirrhosis worldwide. One effective strategy to prevent recurrence or transmission of HBV infection after liver transplantation exists is prescription of Lamivudine, although it is associated with high resistance rates. Adefovir dipivoxil (AD) is a nucleotide analogue of adenosine that has achieved significant results in virologic, biochemical, and clinical parameters in lamivudine-resistant HBV-infected patients. Between 1990 and 2003 7 adult recipients of orthotopic liver transplants who experienced lamivudine-resistant HBV infection (pretransplantation or posttransplantation) were enrolled in a prospective study to administer AD for 48 weeks. At baseline they showed serum HBV DNA between 2.2 x 10(6) and 1.1 x 10(8) copies/mL. After 48 weeks of AD treatment, the median time-weighted average change in serum HBV DNA (log 10 copies/mL) was -3.19 (SD, 1.65). In 3 patients with HBV, DNA was undetectable (<400 copies/mL) at the end of the follow-up. HBe antigen seroconversion was observed in 1 patient. No significant adverse effects were recorded, except for renal functional impairment in 1 patient who had previous renal insufficiency. In our study, adefovir was an effective drug to suppression HBV replication in liver transplant recipients with lamivudine-resistant HBV. Excluding renal function abnormalities, tolerance of the drug was excellent. None of the patients developed resistance to adefovir. Therapy with AD in liver transplant recipients is effective and safe, although renal function should be monitored closely.

Effectiveness and safety of mycophenolate mofetil as monotherapy in liver transplantation.

INTRODUCTION: Calcineurin inhibitors (CIs) cause substantial long-term morbidity and mortality among orthotopic liver transplantation (OLT) patients. Our aim was to evaluate the effectiveness and safety of mycophenolate mofetil (MMF) among OLT patients with CI-related side effects. PATIENTS: Thirty three adult patients, including 29 men and 4 women of mean age 57 years, underwent OLT between 1986 and 2000 under treatment with CIs (28 cyclosporine and five tacrolimus). Mean follow-up after OLT was 59 months. Adverse effects were renal dysfunction in 26, hypertension in 23, and neurotoxicity in two. MMF was added gradually while simultaneously reducing the dosage of CI. RESULTS: After a mean 15-months follow-up of MMF treatment, CIs had been withdrawn in 28 patients (85%). The mean time from the initiation of MMF and CI withdrawal was 5 months. During the first year of follow-up chronic renal dysfunction improved in 16 of 26 patients (61.6%) accompanied by a decreased serum creatinine and urea and an increase in creatinine clearance. Among 13/23 (56.5%) hypertensive patients, there was a significant decrease in blood pressure or the number of antihypertensive drugs (P<.05). One patient with neurotoxicity improved. Twenty-two patients (66%) displayed adverse events: five rejections (15%) including four acute episodes, controlled by CI re-introduction, and one chronic reaction. The most frequent adverse effects were herpes simplex infection in 10 patients (30%), asthenia in nine (27%), diarrhea in five (15%) and thrombocytopenia in four (12%). Nevertheless, only six patients (19%) required MMF dose reduction, namely, three patients with GI intolerance, two with repeated VHS infections, and one with anemia. CONCLUSIONS: MMF monotherapy improves renal function and blood pressure levels in more than 50% of patients with chronic renal impairment and hypertension after OLT. Many of the side effects of MMF were mild; it was safe accompanied by a low incidence of rejection reactions.