Emerging materials and technologies for advancing bioresorbable surgical meshes.

Surgical meshes play a significant role in the treatment of various medical conditions, such as hernias, pelvic floor issues, guided bone regeneration, and wound healing. To date, commercial surgical meshes are typically made of non-absorbable synthetic polymers, notably polypropylene and polytetrafluoroethylene, which are associated with postoperative complications, such as infections. Biological meshes, based on native tissues, have been employed to overcome such complications, though mechanical strength has been a main disadvantage. The right balance in mechanical and biological performances has been achieved by the advent of bioresorbable meshes. Despite improvements, recurrence of clinical complications associated with surgical meshes raises significant concerns regarding the technical adequacy of current materials and designs, pointing to a crucial need for further development. To this end, current research focuses on the design of meshes capable of biomimicking native tissue and facilitating the healing process without post-operative complications. Researchers are actively investigating advanced bioresorbable materials, both synthetic polymers and natural biopolymers, while also exploring the performance of therapeutic agents, surface modification methods and advanced manufacturing technologies such as 4D printing. This review seeks to evaluate emerging biomaterials and technologies for enhancing the performance and clinical applicability of the next-generation surgical meshes. STATEMENT OF SIGNIFICANCE: In the ever-transforming landscape of regenerative medicine, the embracing of engineered bioabsorbable surgical meshes stands as a key milestone in addressing persistent challenges and complications associated with existing treatments. The urgency to move beyond conventional non-absorbable meshes, fraught with post-surgery complications, emphasises the necessity of using advanced biomaterials for engineered tissue regeneration. This review critically examines the growing field of absorbable surgical meshes, considering their potential to transform clinical practice. By strategically combining mechanical strength with bioresorbable characteristics, these innovative meshes hold the promise of mitigating complications and improving patient outcomes across diverse medical applications. As we navigate the complexities of modern medicine, this exploration of engineered absorbable meshes emerges as a promising approach, offering an overall perspective on biomaterials, technologies, and strategies adopted to redefine the future of surgical meshes.

Liver Transplant for Adult Recurrent Hepatic Mesenchymal Hamartoma and a Feasible Treatment Modality: A Case Report and Literature Review.

BACKGROUND: Adult hepatic mesenchymal hamartoma (HMH) is an extremely rare hepatic tumor. Recurrence following complete resection is uncommon. Liver transplantation (LT) is described as a possible treatment option in nonresectable HMH. We conducted a systematic review investigating LT in adult HMH followed by a case report describing evidence of extensive recurrence following complete resection of large right-sided HMH requiring LT. CASE REPORT: A 46-year-old woman with symptomatic large right-hepatic HMH underwent right hemi-hepatectomy with histologic evidence of complete resection. Two and a half years postresection, she presented with abdominal pain and distension; imaging revealed large multi-septated hepatic cystic lesions within the liver suggestive of extensive recurrence of disease with concerns of malignant sarcomatous transformation. After a multidisciplinary team discussion, the lesion was deemed unresectable and the patient was referred for LT. Findings on transplantation included giant multiple hepatic cystic lesions occupying the entire abdomen and histopathological analysis confirmed recurrent HMH with no malignancy. The 6-month follow-up was unremarkable with no signs of postoperative complications or rejection. CONCLUSION: We identified only 3 reported adult unresectable HMH cases in the English literature requiring LT, with good clinical outcome and no rejection on a 1-year follow-up. To our knowledge, we report the first recurrent HMH that required LT in the English literature. Current evidence suggests possible malignant sarcomatous transformation of those lesions. No guidelines exist on postresection surveillance for HMH; however, given their malignant potential, we suggest a benefit of imaging-based surveillance following HMH resection. Offering LT for nonresectable or recurrent HMH is a feasible treatment modality with a reported good outcome.

Umbilical fissure vein, anatomical variation and potential surgical application.

BACKGROUND: The umbilical fissure vein (UFV) is a hepatic vein that travels within the umbilical fissure (or its proximity), providing venous drainage for hepatic segments 3 and 4. Its preservation carries a potential importance in extended right hemi-hepatectomy, left lateral segmentectomy and extended segment 2 resections. METHODS: Consecutive 1-mm slice thickness portovenous phase intravenous contrast computed tomography (CT) scans of the abdomen performed were retrospectively reviewed during the period of June 2019 to July 2019, with two independent investigators investigating the presence of UFV, its course, insertion and relation to the umbilical fissure. RESULTS: A total of 244 CTs were identified and 186 included. The UFV was identified on 72.8% of participants, 109 (81.4%) drained into the main left hepatic vein, while the remaining ones drained either from the main middle hepatic vein (16.4%) or the bifurcation between main left and middle hepatic vein (2.2%). The veins course lay 2 mm or less along the length of umbilical fissure in 39.5%, while 57.5% ran within 1 cm along the length of the umbilical fissure. CONCLUSION: Pre-operative identification of UFV could assist in operative planning. The vein can be used as a landmark in surgery and should be preserved in left lateral segmentectomy and extended right hepatectomy to avoid parenchymal congestion of remnant segments.

Atraumatic splenic rupture in a patient treated with apixaban: A case report.

INTRODUCTION: Splenic rupture is often seen in the context of significant trauma. Atraumatic ruptures are described in the context of malignancy, inflammation or infection directly affecting the spleen. Splenic ruptures occurring in patients taking apixaban, a factor Xa inhibitor, are challenging due to the scarcity of a direct reversal agent. PRESENTATION OF CASE: A 66 year old male presented with syncope and back pain and was found to be haemodynamically unstable and tender in the left upper quadrant. There was no preceding trauma. He has a background of extensive major arterial reconstruction and was taking apixaban for atrial fibrillation. A diagnosis of splenic rupture was confirmed on cross sectional imaging. A laparotomy and splenectomy was necessitated as salvage therapy following splenic artery embolisation. He recovered well and was discharged home 6 days after laparotomy. CONCLUSION: Definitive intervention is required for the management of splenic ruptures. A high level of clinical suspicion should be maintained in patients taking direct oral anticoagulants presenting with haemodynamic instability. Open splenectomy remains the most definitive option for treatment of atraumatic rupture in anticoagulated patients.

Long-term outcome of kidney transplant by using restored kidney grafts after tumour ex vivo excision - a prospective study.

The aim of this study is to report long-term outcomes of kidney transplantation by using the kidney graft after a small tumour ex vivo excision. A structured programme was established to use the restored kidney graft from urological referral after radical nephrectomy. The criteria were defined as tumour size ≤3 cm, margin clear on frozen section and recipients aged ≥60 years or those on the urgent list for transplantation as a result of imminent lack of dialysis access. The recipients were followed up regularly for surveillance of tumour recurrence. Between February 2007 and February 2018, 28 recipients had kidney transplantation by using the restored kidney grafts. The tumour size was 2.6 ± 0.7 cm. The follow-up was median 7 years without evidence of tumour recurrence. The patient and graft survival was satisfactory. Kidney transplantation by using restored kidneys after a small tumour excision is a novel source for selected recipients. The long-term patient and graft survival is satisfactory. Although there is a risk of tumour recurrence, it is rare event. Together with literature review, we would support use of kidney graft after a small tumour excision for selected recipients.

Immune-mediated ECM depletion improves tumour perfusion and payload delivery.

High extracellular matrix (ECM) content in solid cancers impairs tumour perfusion and thus access of imaging and therapeutic agents. We have devised a new approach to degrade tumour ECM, which improves uptake of circulating compounds. We target the immune-modulating cytokine, tumour necrosis factor alpha (TNFα), to tumours using a newly discovered peptide ligand referred to as CSG. This peptide binds to laminin-nidogen complexes in the ECM of mouse and human carcinomas with little or no peptide detected in normal tissues, and it selectively delivers a recombinant TNFα-CSG fusion protein to tumour ECM in tumour-bearing mice. Intravenously injected TNFα-CSG triggered robust immune cell infiltration in mouse tumours, particularly in the ECM-rich zones. The immune cell influx was accompanied by extensive ECM degradation, reduction in tumour stiffness, dilation of tumour blood vessels, improved perfusion and greater intratumoral uptake of the contrast agents gadoteridol and iron oxide nanoparticles. Suppressed tumour growth and prolonged survival of tumour-bearing mice were observed. These effects were attainable without the usually severe toxic side effects of TNFα.

InForm software: a semi-automated research tool to identify presumptive human hepatic progenitor cells, and other histological features of pathological significance.

Hepatic progenitor cells (HPCs) play an important regenerative role in acute and chronic liver pathologies. Liver disease research often necessitates the grading of disease severity, and pathologists' reports are the current gold-standard for assessment. However, it is often impractical to recruit pathologists in large cohort studies. In this study we utilise PerkinElmer's "InForm" software package to semi-automate the scoring of patient liver biopsies, and compare outputs to a pathologist's assessment. We examined a cohort of eleven acute hepatitis samples and three non-alcoholic fatty liver disease (NAFLD) samples, stained with HPC markers (GCTM-5 and Pan Cytokeratin), an inflammatory marker (CD45), Sirius Red to detect collagen and haematoxylin/eosin for general histology. InForm was configured to identify presumptive HPCs, CD45+ve inflammatory cells, areas of necrosis, fat and collagen deposition (p < 0.0001). Hepatitis samples were then evaluated both by a pathologist using the Ishak-Knodell scoring system, and by InForm through customised algorithms. Necroinflammation as evaluated by a pathologist, correlated with InForm outputs (r2 = 0.8192, p < 0.05). This study demonstrates that the InForm software package provides a useful tool for liver disease research, allowing rapid, and objective quantification of the presumptive HPCs and identifies histological features that assist with assessing liver disease severity, and potentially can facilitate diagnosis.

Evaluation of Three-Dimensional Versus Conventional Laparoscopy for Kidney Transplant Procedures in a Human Cadaveric Model.

OBJECTIVES: There are increased reports that kidney transplant can be performed by laparoscopic surgery. The further development of this technique could revolutionize human kidney transplant surgery. However, laparoscopic kidney transplant demands a high level of skill for vascular anastomoses. The emerging technology of the three-dimensional, high-definition laparoscopic system may facilitate the application of this technique. Therefore, in this study, we evaluated this system in performing kidney transplant surgery versus the two-dimensional laparoscopic system. MATERIALS AND METHODS: Four fresh-frozen human cadavers were used in this study, with 2 for the 3-dimensional and 2 for the 2-dimensional system. Kidneys were retrieved by using the retroperitoneoscopic technique for living donor nephrectomy from the same cadaver. The kidney graft was transplanted at the right iliac fossa using a laparoscopic technique by extraperitoneal approach. The procedure was recorded, and the vessel anastomotic time was analyzed. RESULTS: Kidney transplant procedures were conducted successfully in the 3-dimensional, high-definition and the 2-dimensional groups. We recorded no significant differences in terms of vessel anastomotic time between the 2 groups. The total surgery time was shorter in the 3-dimensional, high-definition group than in the 2-dimensional group (P = .02). CONCLUSIONS: This pilot study reinforces that kidney transplant with either the 3-dimensional, high-definition or 2-dimensional laparoscopy is feasible in a human cadaveric model. The operation was the same as open kidney transplant, but the procedure was performed by a laparoscopic approach with a smaller incision.

Bile duct stone formation around a Prolene suture after cholangioenterostomy.

The iatrogenic cause of bile duct stone formation is mainly due to suture materials, especially silk sutures. In recent years, Prolene and Vicryl sutures have been widely used in biliary surgery, and bile duct stone formation related to sutures are seemingly becoming rare, as there has only been one report of bile duct stone formation caused by Prolene sutures in the literature. In the last few years we have had two cases of Prolene suture-related bile duct stone formation within our unit. We therefore suggest that Vicryl sutures should be used as the first choice in biliary surgery, in order to prevent the formation of iatrogenic bile duct stones.

Repair of extrahepatic bile duct defect using a collagen patch in a Swine model.

Extrahepatic bile duct (EBD) injury can happen during surgery. To repair a defect of the EBD and prevent postoperative biliary complications, a collagen membrane was designed. The collagen material was porous, biocompatible, and degradable and could maintain its shape in bile soaking for about 4 weeks. The goal was to induce rapid bile duct tissue regeneration. Twenty Chinese experimental hybrid pigs were used in this study and divided into a patch group and a control group. A spindle-shaped defect (20 mm × 6 mm) was made in the anterior wall of the lower EBD in the swine model, and then the defect was reconstructed using a collagen patch with a drainage tube and wrapped with greater omentum. Ultrasound was performed at 2, 4, 8, and 12 weeks postoperatively. Liver function tests and white blood cell count (WBC) were measured. Hematoxylin-eosin staining, cytokeratin 7 immunohistochemical staining, and Van Gieson's staining of EBD were used. The diameter and thickness of the EBD at the graft site were measured. There was no significant difference in liver function tests or WBC in the patch group compared with the control group. No evidence of leakage or stricture was observed, but some pigs developed biliary sludge or stone at 4 and 8 weeks. The drainage tube was lost within 12 weeks. The neo-EBD could withstand normal biliary pressure 2 weeks after surgery. Histological study showed the accessory glands and epithelial cells gradually regenerated at graft sites from 4 weeks, with increasing vessel infiltration and decreasing inflammation. The collagen fibers became regular with full coverage of epithelial cells. The statistical analysis of diameter and thickness showed no stricture formation at the graft site, but the EBD wall was slightly thicker than in the normal bile duct due to collagen fiber deposition. The structure of the neo-EBD was similar to that of the normal EBD. The collagen membrane patch associated with a drainage tube and wrapped with greater omentum effectively induced the regeneration of the EBD defect within 12 weeks.

A human cadaver model for laparoscopic kidney transplant.

OBJECTIVES: To evaluate the technique of laparoscopic kidney transplant and demonstrate the feasibility of this procedure by an extraperitoneal approach. MATERIALS AND METHODS: The procedure was performed on 2 human cadavers. Retroperitoneal endoscopic left nephrectomy was performed. An extraperitoneal space was established by inflation of a balloon dilator. The external iliac artery and vein were exposed. A Pfannenstiel incision (6 cm) was made and a hand-access device was used. The renal artery was anastomosed to the external iliac artery (end-to-side anastomosis); the renal vein was anastomosed to the external iliac vein (end-to-side anastomosis). The ureter was anastomosed to the bladder with an extravesical tunnelling technique. RESULTS: The donor kidney grafts were obtained successfully. The preparation of the external iliac artery and vein was satisfactory. The entire procedure for the renal artery, renal vein, and ureteral anastomoses was performed with laparoscopic technique without any difficulty. CONCLUSIONS: The present model on human cadavers may provide a feasible approach for training surgeons to perform human laparoscopic kidney transplant. The present technique may be applied to clinical human kidney transplant.

Laparoscopic surgery for kidney orthotopic transplant in the pig model.

BACKGROUND AND OBJECTIVES: Laparoscopic surgery has rapidly expanded in surgical practice with well-accepted benefits of minimal incision, less analgesia, better cosmetics, and quick recovery. The surgical technique for kidney transplantation has remained unchanged since the first successful kidney transplant in the 1950s. Over the past decade, there were only a few case reports of kidney transplantation by laparoscopic or robotic surgery. Therefore, the aim of this study is to develop a laparoscopic technique for kidney transplantation at the region of the native kidney. METHODS: After initial development of the laparoscopic technique for kidney transplant in cadaveric pigs, 5 live pigs (Sus scrofa, weighing 45-50 kg) underwent laparoscopic kidney transplant under general anesthesia. First, laparoscopic donor nephrectomy was performed, and then the kidney was perfused and preserved with cold Ross solution. The orthotopic auto-transplant was subsequently performed using the laparoscopic technique. The blood flow of the kidney graft was assessed using Doppler ultrasonography, and urine output was monitored. RESULTS: The laparoscopic kidney transplant was successful in 4 live pigs. Immediate urine output was observed in 3 pigs. The blood flow in the kidney was adequate, as determined using Doppler ultrasonography. CONCLUSION: It has been shown that laparoscopic kidney orthotopic transplant is feasible and safe in the pig model. Immediate kidney graft function can be achieved. A further study will be considered to identify the potential surgical morbidity and mortality after recovery in a pig model before translating the technique to clinical human kidney transplantation.

Laparoscopic surgery for orthotopic kidney transplant in the pig model.

BACKGROUND: Laparoscopic surgery has become the preferred approach in surgical practice due to multiple benefits. Over the last decade, kidney transplant by laparoscopic or robotic techniques have been explored. The aim of this study is to establish a new laparoscopic technique for kidney orthotopic transplant. MATERIALS AND METHODS: The study was approved by the Animal Ethics Committee of the University. Ten live female pigs (Sus scrofa), weighing 45-50 kg, underwent laparoscopic kidney orthotopic transplant on left side under general anesthesia, and the opposite right kidney was defunctioned by complete ligation of the ureter at the same time. RESULTS: The vital signs of all pigs were stable during the surgery and postoperative period. There were no intraoperative complications and no conversion to open surgery. The laparoscopic kidney transplant was successful in seven of 10 pigs. Seven pigs were observed up to 4 wk as planned in the study. DISCUSSION: To our knowledge, this is the first study of laparoscopic kidney orthotopic transplant in pig model with satisfactory immediate graft function. It was demonstrated that laparoscopic kidney transplant is a feasible, reliable, and safe procedure. However, it is a very demanding technique. Adequate training is mandatory for performing laparoscopic kidney transplant. This study could be used as a training model for surgeons who wish to perform human laparoscopic kidney transplant in the future.

Focal nodular hyperplasia of the liver: pathological analysis of 11 cases.

BACKGROUND: Focal nodular hyperplasia (FNH) is a benign tumor-like lesion of the liver, predominantly affecting women. Its etiology is obscure and its pathogenesis is poorly understood. FNH should be differentiated from other benign and malignant hepatic lesions. The aim of this study was to explore the pathological characteristics of FNH of the liver. METHODS: Eleven patients with FNH were studied retrospectively by using hematoxylin and eosin, immunohistochemical and histochemical staining. RESULTS: In 8 female and 3 male FNH patients aged 19 to 54 years (mean 32), most of lesions showed central scars macroscopically. Microscopically 8 patients were found of classical type, 2 were of telangiectic type, and 1 was of mixed type. CONCLUSION: FNH is an uncommon benign hyperplastic lesion of the liver. It should be differentiated from hepatocellular adenoma, alpha-fetoprotein negative hepatocellular carcinoma, and fibrolamellar carcinoma.

Clinical experience in liver transplantation from an organ transplantation center in China.

OBJECTIVE: To sum up the experience in liver transplantation in a period of ten years at a single center. METHODS: We retrospectively reviewed the clinical records of 120 patients receiving liver transplantation from April 1993 to October 2002. The patients' clinical characteristics, surgical techniques, complications and survival were compared in the phases of 1993-1997 (phase I), 1999 (phase II), and 2000-2002 (phase III). RESULTS: Malignant liver diseases were major indications for liver transplantation in phase I (100%) and II (53.3%), but decreased markedly in percentage in phase III (34.0%). When compared with recipients in phase I and II, the survival of recipients with benign liver diseases in phase III was significantly improved with the 3-month, 6-month and 1-year survival rates of 85.7%, 84.5% and 83.1%, respectively. For patients with malignant liver diseases, the 3-month, 6-month and 1-year survival rates were 87.4%, 81.1% and 46.0%, respectively. The reinfection rate of hepatitis B virus was 24% 12 months after transplantation. With technical refinements, the incidence of postransplantation vascular complications has significantly decreased from 29.4% in phase I and II to 4.9% in phase III. Biliary complications remained one of the major obstacles to long-term survival. No veno-venous bypass was applied in phase III, providing a promising outcome. CONCLUSION: Strict selection of potential recipients, technical refinement, appropriate management of vascular and biliary complications, and prophylaxis of recurrences of hepatitis B and malignant liver diseases are important to obtain long-term survival of patients receiving liver transplantation in China.