Automatic surgical phase recognition in laparoscopic inguinal hernia repair with artificial intelligence.

BACKGROUND: Because of the complexity of the intra-abdominal anatomy in the posterior approach, a longer learning curve has been observed in laparoscopic transabdominal preperitoneal (TAPP) inguinal hernia repair. Consequently, automatic tools using artificial intelligence (AI) to monitor TAPP procedures and assess learning curves are required. The primary objective of this study was to establish a deep learning-based automated surgical phase recognition system for TAPP. A secondary objective was to investigate the relationship between surgical skills and phase duration. METHODS: This study enrolled 119 patients who underwent the TAPP procedure. The surgical videos were annotated (delineated in time) and split into seven surgical phases (preparation, peritoneal flap incision, peritoneal flap dissection, hernia dissection, mesh deployment, mesh fixation, peritoneal flap closure, and additional closure). An AI model was trained to automatically recognize surgical phases from videos. The relationship between phase duration and surgical skills were also evaluated. RESULTS: A fourfold cross-validation was used to assess the performance of the AI model. The accuracy was 88.81 and 85.82%, in unilateral and bilateral cases, respectively. In unilateral hernia cases, the duration of peritoneal incision (p = 0.003) and hernia dissection (p = 0.014) detected via AI were significantly shorter for experts than for trainees. CONCLUSION: An automated surgical phase recognition system was established for TAPP using deep learning with a high accuracy. Our AI-based system can be useful for the automatic monitoring of surgery progress, improving OR efficiency, evaluating surgical skills and video-based surgical education. Specific phase durations detected via the AI model were significantly associated with the surgeons' learning curve.

Application of a novel material in the inguinal region using a totally percutaneous approach in an animal model: a new potential technique?

PURPOSE: To evaluate the feasibility and safety of a new percutaneous image-guided surgery technique to simulate a hernia repair using hydrogel. MATERIALS AND METHODS: A comparative prospective study was conducted in animals, with survival. Five pigs without any hernias were used. A hydrogel was injected at a site corresponding to the preperitoneal inguinal region. This procedure was performed bilaterally. An image-guided needle (ultrasound and computed tomography) was used, through which the material was injected. After survival, the local and systemic inflammatory reaction generated by the new material, was studied. RESULTS: All animals survived the procedure. No hemorrhagic or infectious complications were reported. The solidification of the material occurred as expected. In eight out of ten cases, the material was found in the planned site. No systemic inflammatory reaction secondary to the administration of hydrogel was reported. The adhesion of the material to surrounding tissues was satisfactory. CONCLUSION: The introduction of a liquid material which solidifies after injection in a short time (hydrogel) using a needle is feasible. The combined CT-scan and US image guidance allows for the percutaneous placement of the needle in the required location. The introduced hydrogel remains in this space, corresponding to the inguinal region, without moving. The placed hydrogel compresses the posterior wall composed of the transversalis fascia, supporting the potential use of hydrogel for hernia defects.

Percutaneous Radiofrequency Assisted Liver Partition with Portal Vein Embolization for Staged Hepatectomy (PRALPPS)

BACKGROUND: When a major hepatic resection is necessary, sometimes the future liver remnant is not enough to maintain sufficient liver function and patients are more likely to develop liver failure after surgery. AIM: To test the hypothesis that performing a percutaneous radiofrecuency liver partition plus percutaneous portal vein embolization (PRALPPS) for stage hepatectomy in pigs is feasible. METHODS: Four pigs (Sus scrofa domesticus) both sexes with weights between 25 to 35 kg underwent percutaneous portal vein embolization with coils of the left portal vein. By contrasted CT, the difference between the liver parenchyma corresponding to the embolized zone and the normal one was identified. Immediately, using the fusion of images between ultrasound and CT as a guide, radiofrequency needles were placed percutaneouslyand then ablated until the liver partition was complete. Finally, hepatectomy was completed with a laparoscopic approach. RESULTS: All animals have survived the procedures, with no reported complications. The successful portal embolization process was confirmed both by portography and CT. In the macroscopic analysis of the pieces, the depth of the ablation was analyzed. The hepatic hilum was respected. On the other hand, the correct position of the embolization material on the left portal vein could be also observed. CONCLUSION: "Percutaneous radiofrequency assisted liver partition with portal vein embolization" (PRALLPS) is a feasible procedure (AU)

A step towards stereotactic navigation during pelvic surgery: 3D nerve topography.

BACKGROUND: Long-term morbidity after multimodal treatment for rectal cancer is suggested to be mainly made up by nerve-injury-related dysfunctions. Stereotactic navigation for rectal surgery was shown to be feasible and will be facilitated by highlighting structures at risk of iatrogenic damage. The aim of this study was to investigate the ability to make a 3D map of the pelvic nerves with magnetic resonance imaging (MRI). METHODS: A systematic review was performed to identify a main positional reference for each pelvic nerve and plexus. The nerves were manually delineated in 20 volunteers who were scanned with a 3-T MRI. The nerve identifiability rate and the likelihood of nerve identification correctness were determined. RESULTS: The analysis included 61 studies on pelvic nerve anatomy. A main positional reference was defined for each nerve. On MRI, the sacral nerves, the lumbosacral plexus, and the obturator nerve could be identified bilaterally in all volunteers. The sympathetic trunk could be identified in 19 of 20 volunteers bilaterally (95%). The superior hypogastric plexus, the hypogastric nerve, and the inferior hypogastric plexus could be identified bilaterally in 14 (70%), 16 (80%), and 14 (70%) of the 20 volunteers, respectively. The pudendal nerve could be identified in 17 (85%) volunteers on the right side and in 13 (65%) volunteers on the left side. The levator ani nerve could be identified in only a few volunteers. Except for the levator ani nerve, the radiologist and the anatomist agreed that the delineated nerve depicted the correct nerve in 100% of the cases. CONCLUSION: Pelvic nerves at risk of injury are usually visible on high-resolution MRI with dedicated scanning protocols. A specific knowledge of their course and its application in stereotactic navigation is suggested to improve quality of life by decreasing the likelihood of nerve injury.

Advances in stereotactic navigation for pelvic surgery.

BACKGROUND: Stereotactic navigation could improve the quality of surgery for rectal cancer. Critical challenges related to soft tissue stereotactic pelvic navigation include the potential difference in patient anatomy between intraoperative lithotomy and preoperative supine position for imaging. The objective of this study was to determine the difference in patient anatomy, sacral tilt, and skin fiducial position between these different patient positions and to investigate the feasibility and optimal set-up for stereotactic pelvic navigation. METHODS: Four consecutive human anatomical specimens were submitted to repeated CT-scans in a supine and several degrees of lithotomy position. Patient anatomy, sacral tilt, and skin fiducial position were compared by means of an image computing platform. In two specimens, a 10-degree wedge was introduced to reduce the natural tilt of the sacrum during the shift from supine to lithotomy position. A simulation of laparoscopic and transanal surgical procedures was performed to assess the accuracy of the stereotactic navigation. RESULTS: An up-to-supracentimetric change in patient anatomy was noted between different patient positions. This observation was minimized through the application of a wedge. When switching from supine to another position, sacral retroversion occurred independent of the use of a wedge. There was considerable skin fiducial motion between different positions. Accurate stereotactic navigation was obtained with the least registration error (1.9 mm) when the position of the anatomical specimen was registered in a supine position with straight legs, without pneumoperitoneum, using a conventional CT-scan with an identical specimen positioning. CONCLUSION: The change in patient anatomy is small during the sacral tilt induced by positional changes when using a 10-degree wedge, allowing for an accurate stereotactic surgical navigation. This opens up new promising opportunities to increase the quality of surgery for rectal cancer cases where it is difficult or impossible to identify and dissect along the anatomical planes.

Treatment of giant paraesophageal hernia: pro laparoscopic approach.

PURPOSE: Giant paraesophageal hernias (GPEH) are relatively uncommon and account for less than 5% of all primary hiatal hernias. Giant Secondary GPEH can be observed after surgery involving hiatal orifice opening, such as esophagectomy, antireflux surgery, and hiatal hernia repair. Surgical treatment is challenging, and there are still residual controversies regarding the laparoscopic approach, even though a reduced morbidity and mortality, as well as a shorter hospital stay have been demonstrated. METHODS: A Pubmed electronic search of the literature including articles published between 1992 and 2016 was conducted using the following key words: hiatal hernia, paraesophageal hernias, mesh, laparoscopy, intrathoracic stomach, gastric volvulus, diaphragmatic hernia. RESULTS: Given the risks of non-operative management, GPEH surgical repair is indicated in symptomatic patients. Technical steps for primary hernia repair include hernia reduction and sac excision, correct repositioning of the gastroesophageal junction, crural repair, and fundoplication. For secondary hernias, the surgical technique varies according to hernia type and components and according to the approach used during the first surgery. There is an ongoing debate regarding the best and safest method to close the hiatal orifice. The laparoscopic approach has demonstrated a lower postoperative morbidity and mortality, and a shorter hospital stay as compared to the open approach. A high recurrence rate has been reported for primary GPEH repair. However, recent studies suggest that recurrence does not reduce symptomatic outcomes. CONCLUSIONS: The laparoscopic treatment of primary and secondary GPEH is safe and feasible in elective and emergency settings, especially in high-volume centers. The procedure is still challenging. The main steps are well defined. However, there is still room for improvement to lower the recurrence rate.

Intraoperative fluorescence-based enhanced reality laparoscopic real-time imaging to assess bowel perfusion at the anastomotic site in an experimental model.

BACKGROUND: Fluorescence videography is a promising technique for assessing bowel perfusion. Fluorescence-based enhanced reality (FLER) is a novel concept, in which a dynamic perfusion cartogram, generated by computer analysis, is superimposed on to real-time laparoscopic images. The aim of this experimental study was to assess the accuracy of FLER in detecting differences in perfusion in a small bowel resection-anastomosis model. METHODS: A small bowel ischaemic segment was created laparoscopically in 13 pigs. Animals were allocated to having anastomoses performed at either low perfusion (25 per cent; n = 7) or high perfusion (75 per cent; n = 6), as determined by FLER analysis. Capillary lactate levels were measured in blood samples obtained by serosal puncturing in the ischaemic area, resection lines and vascularized areas. Pathological inflammation scoring of the anastomosis was carried out. RESULTS: Lactate levels in the ischaemic area (mean(s.d.) 5·6(2·8) mmol/l) were higher than those in resection lines at 25 per cent perfusion (3·7(1·7) mmol/l; P = 0·010) and 75 per cent perfusion (2·9(1·3) mmol/l; P < 0·001), and higher than levels in vascular zones (2·5(1·0) mmol/l; P < 0·001). Lactate levels in resection lines with 75 per cent perfusion were lower than those in lines with 25 per cent perfusion (P < 0·001), and similar to those in vascular zones (P = 0·188). Levels at resection lines with 25 per cent perfusion were higher than those in vascular zones (P = 0·001). Mean(s.d.) global inflammation scores were higher in the 25 per cent perfusion group compared with the 75 per cent perfusion group for mucosa/submucosa (2·1(0·4) versus 1·2(0·4); P = 0·003) and serosa (1·8(0·4) versus 0·8(0·8); P = 0·014). A ratio of preanastomotic lactate levels in the ischaemic area relative to the resection lines of 2 or less was predictive of a more severe inflammation score. CONCLUSION: In an experimental model, FLER appeared accurate in discriminating bowel perfusion levels. Surgical relevance Clinical assessment has limited accuracy in evaluating bowel perfusion before anastomosis. Fluorescence videography estimates intestinal perfusion based on the fluorescence intensity of injected fluorophores, which is proportional to bowel vascularization. However, evaluation of fluorescence intensity remains a static and subjective measure. Fluorescence-based enhanced reality (FLER) is a dynamic fluorescence videography technique integrating near-infrared endoscopy and specific software. The software generates a virtual perfusion cartogram based on time to peak fluorescence, which can be superimposed on to real-time laparoscopic images. This experimental study demonstrates the accuracy of FLER in detecting differences in bowel perfusion in a survival model of laparoscopic small bowel resection-anastomosis, based on biochemical and histopathological data. It is concluded that real-time imaging of bowel perfusion is easy to use and accurate, and should be translated into clinical use.

The Business Engineering Surgical Technologies (BEST) teaching method: incubating talents for surgical innovation.

INTRODUCTION: Technological innovation in surgical science and healthcare is vital and calls for close collaboration between engineering and surgery. To meet this objective, BEST was designed as a free sustainable innovative teaching method for young professionals, combining surgery, engineering, and business in a multidisciplinary, high-quality, low-cost, and learning-by-doing philosophy. AIMS: This paper reviews the initial outcomes of the program and discusses lessons learned and future directions of this innovative educational method. METHODS: BEST educational method is delivered in two parts: the first component consisting of live streaming or pre-recorded online lectures, with an interdisciplinary profile focused on surgery, engineering, and business. The second component is an annual 5-day on-site course, organized at IRCAD-IHU, France. The program includes workshops in engineering, entrepreneurship team projects, and in-depth hands-on experience in laparoscopy, robotic surgery, interventional radiology, and flexible endoscopy with special emphasis on the interdisciplinary aspect of the training. A panel of surgeons, engineers, well-established entrepreneurs, and scientists assessed the team projects for potential patent application. RESULTS: From November 2011 till September 2013, 803 individual and institutional users from 79 different countries attended the online course. In total, 134 young professionals from 32 different countries applied to the onsite course. Sixty participants were selected each year for the onsite course. In addition, five participants were selected for a web-based team. Thirteen provisional patents were filed for the most promising projects. CONCLUSION: BEST proved to be a global talent incubator connecting students to high-quality education despite institutional and economical boundaries. Viable and innovative ideas arose from this revolutionary approach which is likely to spin-off significant technology transfer and lead the way for future interdisciplinary hybrid surgical education programs and career paths.

Innovations in minimally invasive surgery: lessons learned from translational animal models.

PURPOSE: Animal models are key elements of surgical research and promotion of new techniques. Inanimate models, anatomical specimens, and living animals are all necessary to solve the various problems encountered by the advent of a new surgical technique. The development of Natural Orifice Transluminal Endoscopic Surgery (NOTES) procedures is a representative model. METHODS: Over 400 experimental procedures were performed in inanimate models, ex vivo tissues and animals to solve all problems faced by the development of NOTES surgery: peritoneal access, gastrotomy closure, exposure, retraction, dissection as well as education to start this new procedure. RESULTS: The successive use of all models allows to identify the ideal solution for each problem and to precisely define the safest and most reliable option to apply the new technique in patients. It allowed to perform the first transvaginal and transgastric cholecystectomy in patients in a safe way. CONCLUSION: Animal experimentation remains necessary as even sophisticated computer-based solutions are unable to model all interactions between molecules, cells, tissues, organisms, and their environment. Animal research is required in many areas to validate new technologies, develop training, let alone its major goal (namely to avoid using patients for experimentation) which is to be the first "model" for the surgeon.

Endoscopic pyloromyotomy: a new concept of minimally invasive surgery for pyloric stenosis.

BACKGROUND AND STUDY AIMS: Pyloric stenosis is currently managed using open or laparoscopic pyloromyotomy. However, with recent improvements in flexible endoscopic instrumentation and techniques, totally peroral endoscopic approaches could reduce the invasiveness of myotomic procedures. The aim of the study was to establish the feasibility and efficacy of endoscopic submucosal pyloromyotomy in a porcine model. METHODS: Four pigs were included in a preliminary study and a 2-week survival study was performed in another four pigs. An esophagogastroduodenoscope was inserted perorally into the stomach. Saline solution was injected into the submucosal space proximal to the pylorus. The gastric mucosa was incised and a 5-cm submucosal tunnel was created. After exposure of the muscular layer in a submucosal tunnel, myotomy of the circular muscle layer was performed until the longitudinal muscular layer was reached. Once myotomy was completed, endoscopic clips were used to re-approximate the mucosal incision. RESULTS: Submucosal dissection, identification of the circular muscular layer, and pyloromyotomy were achieved in all animals. Acute complications such as bleeding and perforation were not observed in any cases. Median pyloric resting pressure was reduced from 16.5 mmHg to 6.1 mmHg immediately after myotomy and 8.4 mmHg at 14 days after myotomy. CONCLUSION: Peroral endoscopic submucosal pyloromyotomy appears to be technically feasible and effective. Potential clinical applications, such as for infantile hypertrophic pyloric stenosis or delayed gastric emptying after esophagectomy, could be considered after confirmation of safety in additional survival studies.

Video. Repeated transvaginal notes: is it possible?

PURPOSE: Transvaginal surgery has been performed by gynecologists for decades with abundant literature supporting its efficacy and safety. Recently, several groups reported on the NOTES transvaginal (TV) approach for extrapelvic disease. Nevertheless, repeated TV access for NOTES has never been reported to date. Two cases of "repeated" TV access for NOTES cholecystectomy after TV hybrid sleeve gastrectomy are described. METHODS: Two women, aged 57 and 32 years, developed symptomatic cholelithiasis respectively 6 and 8 months after TV sleeve gastrectomy for morbid obesity. Sleeve gastrectomy: a 2-cm posterior colpotomy was performed under laparoscopic control between the uterosacral ligaments. A double-channel endoscope and a 60-cm-long laparoscopic grasper were introduced transvaginally. Two abdominal ports were placed to allow the introduction of the stapling device and to assist during the procedure. An intragastric endoscope served to expose the stomach and to calibrate the gastric sleeve, which was performed in the standard fashion. Colpotomy was closed by separate 3/0 Vicryl stitches. At cholecystectomy, an exploratory laparoscopy ascertained the feasibility of a NOTES cholecystectomy. The posterior vaginal vault was carefully examined before regaining peritoneal access with the technique described above. Cholecystectomy was performed by using a double-channel endoscope introduced TV and a 5-mm transabdominal port. Follow-up consisted of 3 and 6 months pelvic examination and interview, which included sexual function assessment by sexual function questionnaire (SFQ31). RESULTS: Both operations were performed successfully with no intraoperative or postoperative complications. At cholecystectomy, minimal pelvic adhesions were found with no vaginal scarring at the colpotomy site. No bleeding, pain, or vaginal infection occurred after both procedures. Patients resumed sexual activity 5.2 weeks postoperatively with a consistently normal SFQ31. CONCLUSIONS: This report suggests that, in experienced hands, repeated TV access for extrapelvic surgery is possible and safe, putting forward the intriguing promises of less adhesions formation.

Multimedia manuscript. Thoracoscopic management of chylothorax after esophagectomy.

BACKGROUND: Chylothorax after esophagectomy is a potentially life-threatening complication, with a reported incidence rate of 1-4%. Two cases of postoperative chylothorax successfully managed thoracoscopically are reported. METHODS: In case 1, a 61-year-old man presenting with an adenocarcinoma of the lower esophagus underwent laparoscopic transhiatal esophagectomy after neoadjuvant chemotherapy. The thoracic duct was identified, and no obvious leaks were detected. The thoracic drain was removed on postoperative day (POD) 6, and chest X-rays were normal. The patient was discharged on POD 10. On POD 20, he was readmitted for acute cardiopulmonary distress. Computed tomography scan showed a massive right collection. After insertion of a chest tube, 8 l of chylous fluid were drained. Once hemodynamic stabilization had been established, the patient was scheduled for surgery. In case 2, a 54-year-old woman presenting with esophageal stenosis after caustic injury refractory to balloon dilation and stenting underwent esophagectomy. Mediastinal dissection was difficult due to fibrotic reaction. On POD 2, the patient presented with a massive chylothorax. In both cases, three trocars were inserted in the right pleural cavity. An incomplete lateral injury of the thoracic duct was found in case 1, and a complete transection proximal to the cervical anastomosis next to the left subclavian was found in case 2. Clips and sutures were used first to seal the duct. Fibrin glue was applied to reinforce the closure. A chest tube was left in place. RESULTS: The operative time was 60 min in case 1 and 55 min in case 2. The chylothorax did not recur, although the postoperative course was longer in case 2 due to associate comorbidities. CONCLUSIONS: The thoracic duct is exposed to injuries during esophagectomies, especially in cases of cancer and postcaustic injuries, leading to fibrotic reaction of the surrounding tissue. Early and delayed chylothorax can be managed efficiently by a thoracoscopic approach replicating the sealing techniques used in thoracotomy.

Long-term results after laparoscopic reoperation for failed antireflux procedures.

BACKGROUND: Surgery for failed antireflux procedures is technically more demanding than primary fundoplication. The success rate does not equal that of the primary procedures. This retrospective analysis aimed to assess long-term subjective and objective outcomes in patients who underwent laparoscopic surgery for fundoplication failure. METHODS: Objective and subjective outcomes were assessed by radiological and endoscopic methods, symptom questionnaire and quality-of-life index at a minimum follow-up of 12 (mean 75·8) months. RESULTS: The study included 129 consecutive patients who had laparoscopic redo surgery after fundoplication had failed. The most frequent patterns of failure were hiatal herniation (50 patients) and slippage (45). Resolution of the symptoms that led to redo surgery was achieved in 27 of 37 and 11 of 16 patients operated for recurrence and for dysphagia respectively. Objective failure was demonstrated in 16 of 39 patients with herniation and six of 22 with slippage. Seven patients underwent an additional surgical procedure. CONCLUSION: Long-term assessment of objective and subjective results after laparoscopic repair for failed fundoplication revealed a high failure rate that increased with the length of follow-up. Unexpected and untreated oesophageal shortening may be responsible for this failure rate.

Single port laparoscopic cholecystectomy: which technique, which surgeon, for which patient? A study of the implementation in a teaching hospital.

BACKGROUND: Single port cholecystectomy is increasingly performed. This procedure can be challenging, and we lack factors predicting the operative difficulty. AIMS: To assess the role of surgeon experience and identify possible predictive factors of intraoperative difficulties. PATIENTS AND METHODS: Sixty-one selected patients were prospectively enrolled between January 2008 and August 2010. Six surgeons were involved (3 seniors, 3 juniors). Anthropometrics of the patients, types of ports, exposure methods and intraoperative data were recorded. Pain was assessed with the visual analogic scale at postoperative day 1 (POD 1 VAS). RESULTS: Fifty-eight patients with symptomatic gallstones and three with acute cholecystitis underwent single port cholecystectomy. The mean BMI, weight and height were 25.7 kg/m(2) (SD 4.45), 71.8 kg (SD 14.83) and 166 cm SD 0.07, respectively. Mean operative time was 68.4 min (SD 26.98). Anthropometrics had no influence on operative time. Senior surgeons performed more rapidly, but the difference was not significant. The overall mean POD 1 VAS was 2.26, (SD 1.81). The mean hospital stay was 2.22 days, (SD 0.9). No complications occurred. An additional exposure method was necessary in 19 procedures. This cluster presented a significantly higher operating time (81.5 min, SD 31.69 vs. 62.7, SD 22.74; p = 0.01) and POD 1 VAS (1.92 vs. 3; p = 0.031). CONCLUSION: Single trocar cholecystectomy can be implemented safely in teaching hospitals. Anthropometrics are not predictive of operative difficulties. The need for additional exposure systems affects the operative time and pain negatively, reflecting greater technical difficulties. Research to optimize instruments may help to solve these problems.

Transgastric hybrid cholecystectomy.

BACKGROUND: Clinical application of natural orifice transluminal endoscopic surgery is under investigation. Preliminary results of transvaginal cholecystectomy in women and associated technical issues have been described. The technique and initial results of hybrid transgastric cholecystectomy are now reported. METHODS: Five patients aged 18-60 years with uncomplicated cholelithiasis underwent transgastric cholecystectomy in a prospective intention-to-treat study that included the option of transparietal assistance (hybrid technique) if needed. The gastrotomy was created under laparoscopic guidance through a 5-mm umbilical trocar, which also served to expose the gallbladder, clip the cystic pedicle and close the gastrotomy. Cholecystectomy was carried out using flexible instruments through the endoscope, alone or in combination with laparoscopic instruments. RESULTS: The procedure was successful in all patients with a median operating time of 150 (range 120-180) min. Transparietal assistance was necessary in all patients. There were no intraoperative or postoperative complications. CONCLUSION: Until technical issues have been resolved, a hybrid procedure with liberal use of transparietal assistance is the safest and most efficient approach for transgastric cholecystectomy. Further studies are essential to evaluate the role of this new approach.

Multimedia article. Combined sentinel node biopsy and localized sigmoid resection entirely by natural orifice transluminal endoscopic surgery: a new challenge to the old paradigm.

INTRODUCTION: We demonstrate localized sigmoidectomy with sentinel node biopsy performed entirely via natural orifice transluminal endoscopic surgery in a porcine model (see Video, Supplemental Digital Content 1, http://links.lww.com/A1170). METHODS: To perform transluminal endoscopic sentinel node biopsy in the sigmoid mesocolon, a conventional double-channel gastroscope created both the gastrotomy and pneumoperitoneum enabling peritoneoscopy. The sigmoid colon was exposed by an intracolonic magnet under extracorporeal control while intraluminal colonoscopy performed lymphatic mapping via submucosal injection of methylene blue dye. After searching the mesocolon for blue-stained lymph channels, the sentinel nodes were resected and retrieved by the intraperitoneal fiberscope. Immediate thereafter localized sigmoidectomy was performed via an additional transcolonic access just above the rectosigmoid junction. With the circular stapler anvil placed early into the proximal colon, mesenteric dissection and proximal transection were performed using conventional laparoscopic instruments worked through a long standard trocar passed transanally through the colotomy. The specimen was delivered per ano (pull-through technique) and the distal margin cross-stapled extracorporeally, including the colotomy within the specimen. Stapled intestinal anastomosis was fashioned by passing a circular stapler transanally (thus returning the rectal stump to its anatomic position) and mating it with the in situ anvil. The gastrotomy was closed as previously described. RESULTS: The operative duration was 31.4 minutes and technical success was readily achieved. Patency and integrity of the anastomosis was confirmed by sigmoidoscopy. CONCLUSION: Oncologically propitious surgery for germinal colonic neoplasia may be encompassed by natural orifice transluminal endoscopic surgery. This provocative proposal challenges the conventional treatment paradigm for early stage colonic neoplasia although much further validation of the concepts involved is required.

Natural orifice transluminal endoscopic surgery (N.O.T.E.S.) for neoplasia of the chest and mediastinum.

Indications for Natural Orifice Transluminal Endoscopic Surgery or NOTES have so far mainly concerned intra-abdominal surgery. The next question to be addressed was whether this access can be extended into other body cavities and, in particular, whether there is a significant role for NOTES above the diaphragm? Using the esophagus, one of the mediastinal organs, as a direct carrier to access the mediastinum and the pleural cavity would eliminate the dissection of the pretracheal fascia required by mediastinoscopy and would give access to the inner part of lung parenchyma. Alternatively, transgastric (or even transvaginal) transhiatal approaches could supplement standard operative techniques in order to minimize abdominal wall ingression. Furthermore, conventional techniques seem disproportionate measures for relatively simple procedures such as evaluating the outcome of chemotherapy and restaging of medically treated mediastinal lesions. As a truly minimal access technique, NOTES could therefore find new indications for intervention. The obvious limiting factor in all of this is assurance of 'leak proof' mural closure. However, if safety of access-site sealing can be established in clinical studies, we could have found an easier, reproducible alternative to the access to mediastinum. This review examines the rationale and evidence for proposing such a venture and deliberates its likely clinical applicability and thereby its potential to become a reality.

3D virtual reality and selective vascular control for laparoscopic left hepatic lobectomy.

BACKGROUND: Careful control of haemostasis is particularly important in laparoscopic hepatic surgery, since a bloodless operative field results in safer and smoother procedures. A selective vascular control for a left lateral segmentectomy may be facilitated by the use of three-dimensional (3D) virtual reality. MATERIALS AND METHODS: A 67-year-old male patient presenting with a 3.5-cm hepatocellular carcinoma (HCC) located between segment II and III of the liver was referred for hepatic resection. Transplant was contraindicated due to previous head and neck cancer surgery. Preoperative 3D reconstruction was used for preoperative planning and allowed a virtual resection to be done as well as peroperative simulation. RESULTS: Five ports were used. The first step was primary control of the hepatic pedicle. 3D virtual-reality reconstruction demonstrated the position of the tumor in the segment and regarding the vessels. The left hepatic artery and the portal vein were successively dissected and controlled. The real anatomy was compared to the virtual-reality reconstruction. Both demonstrated the same anatomy. Vascular section was completed and this resulted in a typical color change of the left lateral segment as well as a small decrease in size. The bisegmentectomy was performed using harmonic dissectors (Autosonix(R), Tyco Healthcare), bipolar cautery, clips, and application of Endo GIA vascular staples (Tyco Healthcare) on the portal pedicles. The procedure was completed following isolation and control of the left hepatic vein. After section, the specimen was placed in a bag and extracted following enlargement of the camera port. Follow-up was uneventful and there was no elevation of hepatic enzymes or postoperative ascites. The patient left the hospital on the fifth postoperative day. CONCLUSION: 3D reconstruction allowed the procedure to be simulated preoperatively. This facilitated the intraoperative identification of the vascular anatomy and the control of the left lateral segment arteries and veins, thus preventing intraoperative bleeding. The use of this approach in preoperative planning is recommended.

Gastric lymphatic mapping for sentinel node biopsy by natural orifice transluminal endoscopic surgery (NOTES).

BACKGROUND: Sentinel node biopsy is proposed as sufficiently reliable in determining the lymph node status of early gastric cancer to justify curtailed resection margins if negative. Its performance by natural orifice transluminal endoscopic surgery (NOTES) could therefore expand the patient cohort able to undergo solely endoscopic resection of their primary. METHODS: A transvaginal NOTES technique was utilized in six pigs (mean weight 30 kg). The posterior colpotomy and pneumoperitoneum was created by a standard double-channel flexible videoendoscope which was then used to perform peritoneoscopy. Concomitant gastroscopy allowed selection of a site along the greater curvature for lymphatic mapping by submucosal injection of methylene blue (3 ml). Furthermore, torque upon this endoscope allowed the posterior surface of the stomach and retrogastric space to become accessible to the transvaginal endoscope. In surveying the mapping in vivo, the intraperitoneal scope could follow blue-stained efferent lymphatic channels to their first-order draining nodes (i.e., sentinel nodes). Conventional instruments worked down the scope's channels were then used to perform the excisional biopsy. At procedure end, the animals underwent immediate laparotomy to ensure the safety and adequacy of the procedure. RESULTS: Each procedure was technically successful. Colpotomy, pneumoperitoneum, and peritoneoscopy were promptly achieved (mean 8 min). Post injection, blue efferent lymphatic channels were immediately appreciable in every animal. Five animals had sentinel nodes in their retropyloric region while the last mapped cephalad towards the esophagogastric junction. Two animals had alternative drainage channels identifying additional sentinel nodes. All blue nodes were dissected cleanly by the intraperitoneal scope and retrieved intact per vaginam. Mean lymphadenectomy time was 19 min. At laparotomy, there was no hematoma, ongoing hemorrhage, or visceral injury in any pig. There were no residual, missed stained nodes or channels. CONCLUSION: NOTES sentinel node biopsy for the stomach is technically accomplishable in this experimental model. This proof of concept should encourage serious consideration of its applicability to clinical practice.