Laparoscopic transperitoneal repair of flank hernias: a retrospective review of 27 patients

Introduction  

Incisional hernias of the flank are rare with scattered case reports regarding the feasibility of laparoscopic treatment. Treatment can be technically challenging due to patient positioning and adequate mesh overlap and fixation. The aim of this study is to describe the surgical technique and present outcomes of the largest known case series of laparoscopic repair of flank hernia.     

Characterization of bionanocomposite scaffolds comprised of amine-functionalized single-walled carbon nanotubes crosslinked to an acellular porcine tendon

Carbon nanotubes (CNT) possess many unique electrical and mechanical properties that make them useful for a variety of industrial and biomedical applications. They are especially attractive materials for biomedical applications since their dimensions are similar to components of the extracellular matrix. In this study, amine-functionalized single-walled carbon nanotubes were crosslinked to an acellular porcine diaphragm tendon. The resulting bionanocomposite scaffolds were subjected to a number of materials characterization techniques including a collagenase assay, uniaxial tensile testing, modulated differential scanning calorimetry, and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy to determine whether the properties of the original extracellular matrix were altered by the treatment processes. A variety of SWCNT concentrations were investigated. While none of the conditions investigated resulted in bionanocomposites with significantly improved physicochemical properties, no detrimental effects were observed due to any of the processing steps. Future studies should be performed to determine if carbon nanotubes can influence cellular adhesion and function in order to promote rapid integration and remodeling.     

Assessment of the biocompatibility of two novel, bionanocomposite scaffolds in a rodent model

The purpose of this study was to evaluate and compare plasma pharmacokinetics, lung tissue concentration, and the potential toxicity of drug eluting beads loaded with irinotecan (DEB-IRI) in a sheep pulmonary artery chemoembolization (PACE) model. Sheep (n = 24) were embolized with DEB-IRI loaded with different doses (0, 20, 50, or 100 mg). Direct pulmonary artery (PA) injections of irinotecan were also performed at two doses (50 or 100 mg; n = 4 sheep). Irinotecan was quantified in plasma and lung tissue (liquid chromatography-fluorescence detection); pathological examination of lungs was performed 4 days or 4 weeks after PACE. Irinotecan was detected in the systemic circulation within a few minutes after PACE, for several hours in DEB-IRI 20 and DEB-IRI 50 groups, and for 24 hours for DEB-IRI 100. Both Cmax and AUC values increased significantly with dose (p = 0.0078 and p = 0.0008, respectively) after PACE. Cmax and AUC values were significantly reduced (by 80%, p = 0.0036, and by 50%, p = 0.0393, respectively) after PACE than after direct PA injection. Irinotecan was not detected in tissue 4 days after PACE. No sign of lung toxicity was observed, except a limited hemorrhagic angionecrosis seen 4 days after PACE with DEB-IRI 100. Inflammatory response on beads was moderate in all DEB-IRI groups. Compared to other routes of administration, DEB loaded with irinotecan at doses up to 100 mg was well tolerated. DEB loaded with 100 mg irinotecan seem a promising candidate for future PACE trials in patients.     

Laparoscopic parastomal hernia repair using a nonslit mesh technique

Background The management of parastomal hernia is associated with high morbidity and recurrence rates (20–70%). This study investigated a novel laparoscopic approach and evaluated its outcomes. Methods A consecutive multi-institutional series of patients undergoing parastomal hernia repair between 2001 and 2005 were analyzed retrospectively. Laparoscopy was used with modification of the open Sugarbaker technique. A nonslit expanded polytetrafluoroethylene (ePTFE) mesh was placed to provide 5-cm overlay coverage of the stoma and defect. Transfascial sutures secured the mesh, allowing the stoma to exit from the lateral edge. Five advanced laparoscopic surgeons performed all the procedures. The primary outcome measure was hernia recurrence. Results A total of 25 patients with a mean age of 60 years and a body mass index of 29 kg/m² underwent surgery. Six of these patients had undergone previous mesh stoma revisions. The mean size of the hernia defect was 64 cm², and the mean size of the mesh was 365 cm². There were no conversions to open surgery. The overall postoperative morbidity was 23%, and the mean hospital length of stay was 3.3 days. One patient died of pulmonary complications; one patient had a trocar-site infection; and one patient had a mesh infection requiring mesh removal. During a median follow-up period of 19 months (range, 2–38 months), 4% (1/25) of the patients experienced recurrence. Conclusion On the basis of this large case series, the laparoscopic nonslit mesh technique for the repair of parastomal hernias seems to be a promising approach for the reduction of hernia recurrence in experienced hands. Presented at the Plenary Session of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) 2006 Annual Meeting, Dallas, Texas, April 2006     

Abnormal primary tissue collagen composition in the skin of recurrent incisional hernia patients

Recurrence of incisional hernia may be as high as 50 per cent. Abnormal collagen I/III ratios have been observed within scar tissue of patients with recurrent incisional hernias. We sought to determine whether collagen composition in primary, nonscarred tissue was similarly affected in these patients. In this prospective, case-control study, nonscarred, primary abdominal wall skin and fascia biopsies were obtained in 12 patients with a history of recurrent incisional hernias and 11 control subjects without any history of hernia while undergoing abdominal laparoscopic surgery. Tissue protein expression of collagen I and III was assessed by immunohistochemistry followed by densitometry analysis. The collagen I/III ratio in skin biopsies from the recurrent hernia group was significantly less compared with control subjects (0.88 +/- 0.01 versus 0.98 +/- 0.04, respectively, P < 0.05). Fascia biopsies from patients with recurrent hernias was not significantly decreased in collagen I/III ratio compared with control subjects (0.90 +/- 0.04 versus 0.94 +/- 0.03, respectively, P = 0.17). Decreased collagen I/III ratios within the skin of patients with recurrent hernias not involved with scar or healing tissue suggest an underlying collagen composition defect. Such a primary collagen defect, in addition to abnormal scar formation, likely plays a significant role in the pathogenesis of recurrent incisional hernias.     

Does a one-day course influence surgeon adoption of laparoscopic ventral herniorrhaphy?

BACKGROUND: New laparoscopic techniques introduced after residency have created a new teaching paradigm focused on animate courses and preceptor instruction. The aim of this study was to test the effectiveness of animate course instruction in teaching laparoscopic ventral hernia repair (LVHR), its success in relationship to the course participants' previous minimally invasive surgery experience, and the role of preceptors in adapting these techniques. METHODS: Surgeons participating in a one-day LVHR course (lectures/animal laboratory) at the Carolinas Medical Center were surveyed concerning professional demographics, prior laparoscopic experience, and their performance of LVHR before and after the encounter. Standard statistics were used to determine significance (P<0.05). RESULTS: Of the 234 surgeons attending a LVHR course between 1999 and 2004, 171 (73%) answered the survey. Mean follow-up after the course was 427 days (range: 34-1202 d). Mean age was 45.9 years (range: 28-67 y). Mean time since residency was 14.4 years (range: 0.5-37 y), and 106 (62%) had learned at least basic laparoscopy in residency. One hundred twenty-six (73.7%) were in private practice. Since the course, 122 (71.3%) had performed a LVHR. They had performed a total of 2049 LVHRs (mean: 16.5; range: 1-102) compared with 1098 open herniorrhaphies (mean: 9; range: 1-23). There was no difference between those performing and not performing LVHR or the number executed with respect to practice type (P=0.67), age (P=0.47), years in practice (P=0.19), or laparoscopic experience in residency (P=0.42). Fifty-four (32%) surgeons had been precepted, and all have since performed LVHR. Surgeons with advanced laparoscopic experience were more likely to perform LVHR compared with those with only laparoscopic cholecystectomy experience (87% versus 33%, P=0.02). Indeed, of those with only laparoscopic cholecystectomy experience who performed LVHR, 80% were precepted. In the subset of surgeons who had not yet performed LVHR, 28 intended to start, 17 requested assistance, and 4 planned not to begin. CONCLUSIONS: A one-day course impacts surgeon practice patterns despite age or type of practice. Surgeons with advanced laparoscopic skills are more likely to perform LVHR. Most with limited experience will begin after working with a preceptor. Didactic instruction and a precepted experience may determine the future performance of advanced laparoscopy.     

人T-bet基因的体外扩增及克隆和鉴定

目的:克隆人T-bet基因,构建其真核表达载体pEGFP-C1-T-bet。方法:实验于2005-07/2006-07在北京大学深圳医院中心实验室完成。①根据Genebank的人T-bet基因的全长cDNA序列,设计合成一对附加BglⅡ和SalⅠ两个限制性内切酶酶切位点的特异性引物。②分离人外周血单个核细胞,提取RNA,用反转录-聚合酶链反应方法将T-bet的编码序列cDNA扩增,装入pMD18-T载体并送去测序。③BglⅡ SalⅠ双酶切质粒pMD18-T-bet,经琼脂糖电泳切胶回收T-bet片段,将T-bet插入载体pEGFP-C1构建成重组真核表达载体pEGFP-C1-T-bet。④用双酶切和聚合酶链反应对插入片段进行分析和验证。结果:①反转录-聚合酶链反应产物经琼脂糖电泳结果显示在预期位置有相对分子质量为1608bp的特异性扩增带。②测序结果证实,T-bet的编码序列和Genbank中T-bet mRNA序列相同。③双酶切和聚合酶链反应结果证实插入片段序列正确。结论:实验成功扩增出人T-bet基因,构建了基因重组真核表达载体pEGFP-C1-T-bet,为探索T-bet基因对免疫细胞的调节作用和肿瘤基因治疗奠定了基础。     

大环骨架结构的倍半萜化合物——Ⅵ.马兜铃新内酯的化学结构测定

自绵毛马兜铃(Aristolochia mollissima Hance)根茎中分得九个化合物,其中已报道的七个化合物是尿囊素、马兜铃内酯、绵毛马兜铃内酯、β-谷甾醇、马兜铃酸A、9-乙氧基马兜铃内酯和9-乙氧基马兜铃内酰胺,本文报道结晶K₃的化学结构,经光谱分析(IR,¹H-NMR,¹³C-NMR,2D-NMR和MS),化学反应及X-衍射晶体分析,确证K₃为一个新骨架结构的倍半萜化合物,命名为马兜铃新内酯。