João Vicente Machado Grossi

Training for laparoendoscopic single-site surgery (LESS).

BACKGROUND Laparoendoscopic single-site surgery (LESS) is a laparoscopic surgery in which a single small incision is made, associated with the use of a special device (single-port), or several small incisions grouped in one location (single-incision) are made, through which the laparoscopic trocars are inserted. The incision is made in the abdomen, preferably in the umbilicus. Certain peculiarities are noted in this approach, such as the difficulty, and sometimes the impossibility, of centering the image, the need to move both the camera and instruments together, requiring even more delicate and precise movements than in laparoscopy. Since information on training for LESS is scarce in the current literature, the authors report their experience with five different cases of this nature, performed in two porcine models, and then discuss a training plan for LESS. METHODS Five LESS procedures were performed in two pigs using different training techniques: two (one single-port and one single-incision) transumbilical laparoscopic cholecystectomies; one right-sided single-incision laparoscopic radical nephrectomy; one single-incision transumbilical laparoscopic radical nephrectomy; and one single-port transumbilical laparoscopic nephrectomy. DISCUSSION Different from what was observed in the transition from open surgery to laparoscopy, the Halstedian model should not be used in the teaching of LESS since this procedure requires that professionals partner together, thus requiring not only the training of surgeons, but of the whole team. CONCLUSION LESS procedures are feasible and considered as further refinements in laparoscopic techniques. However, the peculiarities and difficulties inherent in these procedures require a specific training program combining theory and practice. The authors believe that this training is essential to achieve proficiency levels before the technique can be tried on human subjects.

May polyester with collagen coating mesh decrease the rate of intraperitoneal adhesions in incisional hernia repair

BACKGROUND Among meshes used in incisional hernias in open technique repair, the polypropylene is the most commonly used due to flexibility, cellular growth stimulation, satisfactory inflammatory response, easy manipulation and low price. However, it induces adhesions formation when in contact with the intra-abdominal contents. AIM To evaluate the formation of adhesions after polypropylene and collagen coated polyester mesh with intraperitoneal placement. METHODS Twenty six female Wistar rats were randomized in three groups. In the group 0 (sham) there was no prosthesis placement, in the polypropylene (group 1) the prosthesis was placed at the peritoneal surface and in the group 2, collagen coated polyester mesh was placed. The rats were killed on postoperative day 21 to evaluate adhesions regarding its degree, mesh percentage of involvement, bowel involvement and strength needed to cause rupture. RESULTS There was no difference in weight between groups. The group 0 did not develop any adhesions. The groups 1 and 2 developed prosthetic mesh surface adhesions, mostly in the omentum. There was no difference in adhesion degree and percentage of surface involvement between groups. The collagen coated mesh did not develop adhesions. The adhesions occurred at the free edge of the mesh, in contact with the polyester. The Polypropylene group presented 80% of the surface involved with adhesions, while the collagen coated polyester group presented 10% (p<0,005). CONCLUSION There was no difference between adhesion, degree of adhesion and strength needed to cause rupture. However, the polypropylene mesh presented significantly higher surface of adhesion when compared to the collagen coated polyester mesh.

Analysis of adhesions resulted from mesh fixation with fibrin sealant and suture: experimental intraperitoneal model

OBJECTIVE To compare surgical fixation of polypropylene mesh (PP) and coated polypropylene mesh (PCD) using polypropylene suture and fibrin glue, as for the formation of intraperitoneal adhesions. METHODS A sample of 46 female Wistar rats were randomized into six groups: two control groups, with five rats each, were subjected to one medial incision (MI) and the other to a U-shaped incision (UI), none of these groups received the mesh. Two groups of PP mesh, with ten rats, fixed with suture (PPF), the other with six rats, fixed with biological glue (PPC). And two groups of PCD mesh, at first, with ten animals, the mesh was fixed with sutures (PCDFs) and the second with ten animals with biological glue (PCDC). RESULTS After 21 days, the control groups showed no significant adhesions. The PPC group showed a lower degree of adhesion than the PPF group (p = 0.01). There was no difference between the groups with PCD. CONCLUSION Comparison of fixation was statistically different only with PP mesh, with lesser degrees of adherence when using the glue. Adhesions were predominantly located at the extremities of the meshes studied.

Comparative study of intraperitoneal adhesions associated with the use of meshes of polypropylene and polypropylene coated with omega-3 fatty acid

OBJECTIVE To compare intraperitoneal adhesion formation with placement of polypropylene mesh and use of lightweight polypropylene mesh coated with omega-3 fatty in rats. METHODS Twenty-seven Wistar rats were randomized into three groups. In group 0 no mesh was placed; in group 1 we implanted a polypropylene mesh; and in group 2 there was implantation of a polypropylene mesh coated with omega-3 fatty acid. We evaluated adhesions presence and degree, breaking strength, percentage of area covered and retraction of the implanted meshes. RESULTS Group 0 had no adhesion. Groups 1 and 2 showed adhesions on the surface of the mesh, omentum, liver and intestinal loops. There were grades 1 and 2 adhesions in 100% of the polypropylene coated group and in 60% of the polypropylene group. The remaining were grade 3 adhesions, and differed significantly between groups (p <0.001). The breaking strength of adhesions on the polypropylene coated group was significantly higher than with the polypropylene alone (p = 0.016). There was no difference in mesh retraction or area covered by the mesh. The analysis of the mesh coated with omega-3 fatty acid distribution showed adhesions preferentially located at the edges when compared to polypropylene, predominantly in the center. CONCLUSION The type of adhesions, percentage of surface affected and retraction were not significantly different between meshes. The fatty acids coated mesh had a lower degree of adhesions and these required a greater force to rupture, possibly by their occurrence at the edges of the mesh.

Inguinal hernia repair: can one identify the three main nerves of the region?

OBJECTIVE To identify the nerves in the groin during inguinal hernia repair by inguinotomy. METHODS We conducted a prospective, sequenced, non-randomized study comprising 38 patients undergoing inguinal hernia repair with placement of polypropylene mesh. RESULTS The male patients were 36 (94.7%), with a mean age and standard deviation of 43.1 ± 14.5, body mass index of 24.4 ± 2.8. Comorbidities were hypertension in two (5.2%), smoking in 12 (31.5%) and obesity in two (5.2%). The hernia was located only on the right in 21 (55.2%) patients, only on the left in 11 (28.9%), and was bilateral in six (15.7%) patients. Prior hernia repair was present in seven (18.4%) patients. The identification of the three nerves during operation was made in 20 (52.6%) patients, the ilioinguinal nerve and the iliohypogastric nerve were identified in 33 (86.8%), and the genital nerve branch of the genitofemoral nerve, in 20 (52.6%). Resection of at least one of the nerves was performed in seven (18.4%) cases, two iliohypogastric nerves and five ilioinguinal nerves. The average operating time was 70.8 ± 18.2 minutes. The hospital stay was 1.42 ± 1.18 days. Ten patients (26.3%) returned to physical activity around the first postoperative visit, and 37 (97.3%) in the last. The follow-up time was 95.6 ± 23.5 days. The inability to identify the ilioinguinal nerve was associated with previous repair (p = 0.035). CONCLUSION The identification of the three nerves during inguinal hernia surgery has been described in more than half of the cases and prior repair interfered with the identification of ilioinguinal nerve.

Description of the technique of upper gastrointestinal series radiological examination for the evaluation of the esophagus, stomach and duodenum of Wistar female rats

PURPOSE To evaluate the anatomy of female Wistar rats and the workability of contrast radiography as a technique to investigate the gastrointestinal series. METHODS Eight adult female Wistar rats were undergone to the contrast radiography as anteroposterior incidence and as posterior incidence in profile. The radiological examination was conducted at a 45 degrees angle to the radiological table. Film-focus distance (FFD) was 100 cm, film-object distance (FOD) was 0 cm, and object-focus distance (OFD) was 100 cm. An orogastric probe was used to inject barium contrast at 5-min intervals, for a total of four applications. After the radiological examination, animals were necropsy for confirmation of the radiological findings, and the radiographs were the absence of the normal anatomy variations inspected and described by an experienced radiologist. RESULTS All the radiographs produced achieved satisfactory results in terms of position, exposure, location and quality. The upper esophageal sphincter (UES) was identified in the esophagus at the nerve C2, the lower esophageal sphincter (LES) was identified between spinal cord segments L1 and L2, the thoracic-abdominal junction was observed at T10, the esophageal-gastric junction (EGJ) at T13-L1, with the abdominal portion in the epigastric region. The stomach was observed mostly in the epigastric region, left hypochondrium, left and mesogastric flank. The duodenum findings presented higher variation, with most findings identified in the epigastric region, right hypochondrium, right flank and mesogastric ileal fossa at T13-L5. CONCLUSION Contrast radiology is useful and may be employed to assess the anatomy of the animal being studied. The experimental model described afforded to fully identify all organs investigated, as well as other occasional relevant findings. No anatomical anomalies in the subsequent necropsy, confirming the radiographic findings.

Radiological evaluation of the patency of duodenal-esophageal anastomosis during a long postoperative follow-up: effectiveness of an alkaline reflux model in rats

Background: Performing experimental studies has played an important role in acquiring knowledge about esophageal carcinogenesis. In this context, the choice of a more reliable experimental model requires proof of its effectiveness in order to lend greater credibility to the results. The objective of this study was to evaluate the patency of duodenal-esophageal anastomosis during long-term postoperative follow-up in rats. Methods: This was an experimental study in which 45 female Wistar rats were used. A side-to-side anastomosis was performed, going from the anterior side of the esophagus to the second duodenal portion. A standardized radiological technique was used to carry out a contrasted radiological study of the esophagus, stomach, and duodenum during weeks 4, 12, 20, and 30 after surgery. Different contrast media were used, and the animals were divided into groups, ie, group 1 (100% barium sulfate), group 2 (50% barium sulfate), and group 3 (60% aqueous iodinated contrast media). Contrast radiographs were taken in each group at weeks 4, 12, 20, and 30 after the surgical procedure. The radiographic images were evaluated by two radiologists who were blinded regarding the contrast groups. Macroscopic evaluation of each animal was compared with the radiological findings. Results: Postoperative mortality was 13.33%. The remaining animals were divided into study groups. All the contrast radiological examinations showed evidence of the location of the esophagus, stomach, and proximal portion of the intestine, and demonstrated the laterolateral relationship of the distal esophagus and the duodenum in the epigastric region. Patency of the anastomosis was observed at each examination period. The different contrast media used were able to demonstrate this outcome shortly after the first phase of injection. Necropsies corroborated the radiological findings. Conclusion: Regardless of the contrast agent used, contrasted radiography revealed that side-to-side duodenal-esophageal anastomosis in rats allowed patent communication during long-term postoperative follow-up.