Studies On The Special Operative Devices And Related Applications For Laparoendoscopic Single-Site Surgery

Background:Laparoendoscopic single-site surgery (LESS) is a rapidly evolving field in minimally invasive surgery. Given the parallel entry of working instruments through a single incision in LESS, loss of triangulation in the abdominal cavity, counteracting movements of the instruments, linear laparoscopic perspective and lack of traction are inevitable obstacles. A lot of dedicated apparatus of LESS are developed, such as many LESS trocars, different types of instruments and a variety of retractors. However, they are not suitable for LESS completely. Compared to conventional laparoscopic surgery (CLS), LESS is difficult for operators. Its basic operating rules, benefits for patients and preventing measures of complications are unclear. This study is aimed to develop dedicated apparatus for LESS, confirm their reliability and safety and conclude the basic operating rules through animal experiments. At the same time, clinical researchs are performed to confirm the patients’benefits of LESS, and the incision healing of LESS at linea alba is enhanced by biological methods in animals.Methods:(1) A novel flexible multichannel port, a curved laparoscopic multifunctional operative device and a fish hook retractor were developed according to the special needs of LESS. Laparoendoscopic single-site cholecystostomy and distal pancreatectomy in pigs were performed using the new developed dedicated apparatus to confirm their reliability and safety, and to investigate the feasibility of sophisticated operations of LESS and summarize the basic operation rules of LESS. (2) LESS vs CLS appendectomy RCTs, LESS vs CLS cholecystectomy historical cohort study and case reports of LESS transabdominal preperitoneal hernia repair (TAPP) were performed to confirm the benefits of LESS. (3) Bone morphogenetic protein-12 (BMP-12) induced tenogenic differentiation of mesenchymal stem cells (MSCs) in vitro, then differentiated MSCs-sponge compound was constructed to plant on the incision of LESS at linea alba to enhance its healing.Results:(1) A novel flexible multichannel port is developed successufully and obtains the relevant patents and registered production license. Its main features are flexible material made, air tightness reliable, and having a spacious spacing between channels to effectively avoid collision of apparatus. The curved laparoscopic multifunctional operative device has many functions as cutting, coagulation, curettage, dissection, irrigation, aspiration, and can avoid collision of apparatus and save operation time. The fish hook retractor can be easily developed using common materials and can be easily set up and released. Laparoendoscopic single-site cholecystostomy and distal pancreatectomy in pigs are performed successfully, providing a favorable operative field. There is an umbilical hernia formation two months after LESS cholecystostomy and a death during the operation of LESS pancreatectomy. The basic operation rules of LESS are concluded:axis of umbilicus-object-video, reversed pyramid placement of instruments, ergonomic and geometric tricks, assistant rules, progressive learning and comprehensive optimization. (2) Totally 98 cases of appendectomy are included in RCTs, the operation time of LESS being longer than CLS (90.71±33.25min vs 74.9±46.94min, P=0.057), conversion rate being significant different (P=0.041) with 4 cases of conversion in LESS and cosmetic results favoring LESS (P<0.001).23 cases of LESS cholecystectomy are involved in the historical cohort study. Operation time, conversion rate, bleeding, hospital duration and complications are not significant different between LESS and CLS (P>0.05). Cosmetics of LESS is better than CLS (P=0.021).2 cases of LESS-TAPP are performed successfully, and no complications are developed during 6 months postoperatively. (3) MSCs is successfully isolated and characterized from bone marrow, and 10ng/ml is confirmed the best for BMP-12 inducing tenogenic differentiation of MSCs marked by Sex, collagen I and collagen III with real-time PCR and western blot. A seriers of signal pathways are involved in the differentiation, with Smad being the strongest, phosphorylation of P38 and JNK being delayed and ERK pathway being not activated. Four weeks after planting differentiated MSCs-sponge compound, the experimental group has the strongest tension compared to other control groups (P<0.05), upto 69.7% of normal group. HE and Masson staining show that the regenerating collagen fibers are richer than control groups, the fibers are separating clearly from the abdominal muscle and its arrangement is more parallel.Conclusions:(1) The novel flexible multichannel port, curved laparoscopic multifunctional operative device and fish hook retractor are effective, reliable, safe, and very suitable for LESS.(2) Conclude the basic operation rules of LESS:axis of umbilicus-object-video, reversed pyramid placement of instruments, ergonomic and geometric tricks, assistant rules, progressive learning and comprehensive optimization.(3) Clinical applications demonstrate that LESS is more difficult than CLS, with longer operation time and higher conversion rate. However, the complication is not increased and better cosmetic result is the most advantage of LESS.(4) BMP-12 induces tenogenic differentiation of MSCs through many signal pathways with Smad being the strongest, phosphorylation of P38 and JNK being delayed and ERK pathway being not activated. Tenogenic differentiation of MSCs can enhance the healing of linea alba incision of LESS.