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.

A novel method for near-infrared fluorescence imaging of the urethra during perineal and transanal surgery: demonstration in a cadaveric model

AIM

Transanal total mesorectal excision is a promising novel sphincter-saving procedure for low rectal cancer. However, the transanal bottom-up dissection is associated with increased rates of iatrogenic urethral injuries. Near-infrared fluorescence (NIRF) imaging, given its deeper tissue penetration, has been explored in a limited number of studies for enhanced intra-operative urethral visualization. In this study, we explored the feasibility of a novel, ultrabright, biocompatible fluorescent polymer to coat urinary catheters for the purpose of intra-operative urethral visualization.

METHODS

In an ex vivo experiment, using a near-infrared laparoscope, the fluorescent signal of a coated catheter (near-infrared coating of equipment, NICE) was qualitatively and quantitatively compared to the signal of indocyanine green (ICG)/Instillagel® mixtures and ICG-filled catheters at several concentrations. Also, in three male human torsos, using fluorescent urinary catheters, NIRF-guided perineal dissections and a transanal total mesorectal excision were performed. Intra-operative NIRF-based urethral visualization was performed systematically.

RESULTS

During the qualitative and quantitative fluorescence signal assessment, NICE-coated catheters were clearly superior to the ICG-based solutions. In the cadaveric experiments, enhanced urethral visualization was possible even at early stages of dissection, when the organ was covered by several tissue layers.

CONCLUSIONS

NICE-coated catheters represent a promising potential to allow for NIRF-based intra-operative urethral visualization.

Intraoperative imaging for remnant viability assessment in bilateral posterior retroperitoneoscopic partial adrenalectomy in an experimental model

BACKGROUND

A surgical approach preserving functional adrenal tissue allows biochemical cure while avoiding the need for lifelong steroid replacement. The aim of this experimental study was to evaluate the impact of intraoperative imaging during bilateral partial adrenalectomy on remnant perfusion and function.

METHODS

Five pigs underwent bilateral posterior retroperitoneoscopic central adrenal gland division (9 divided glands, 1 undivided). Intraoperative perfusion assessment included computer-assisted quantitative fluorescence imaging, contrast-enhanced CT, confocal laser endomicroscopy (CLE) and local lactate sampling. Specimen analysis after completion adrenalectomy (10 adrenal glands) comprised mitochondrial activity and electron microscopy.

RESULTS

Fluorescence signal intensity evolution over time was significantly lower in the cranial segment of each adrenal gland (mean(s.d.) 0·052(0·057) versus 0·133(0·057) change in intensity per s for cranial versus caudal parts respectively; P = 0·020). Concordantly, intraoperative CT in the portal phase demonstrated significantly lower contrast uptake in cranial segments (P = 0·031). In CLE, fluorescein contrast was observed in all caudal segments, but in only four of nine cranial segments (P = 0·035). Imaging findings favouring caudal perfusion were congruent, with significantly lower local capillary lactate levels caudally (mean(s.d.) 5·66(5·79) versus 11·58(6·53) mmol/l for caudal versus cranial parts respectively; P = 0·008). Electron microscopy showed more necrotic cells cranially (P = 0·031). There was no disparity in mitochondrial activity (respiratory rates, reactive oxygen species and hydrogen peroxide production) between the different segments.

CONCLUSION

In a model of bilateral partial adrenalectomy, three intraoperative imaging modalities consistently discriminated between regular and reduced adrenal remnant perfusion. By avoiding circumferential dissection, mitochondrial function was preserved in each segment of the adrenal glands. Surgical relevance Preservation of adrenal tissue to maintain postoperative function is essential in bilateral and hereditary adrenal pathologies. There is interindividual variation in residual adrenocortical stress capacity, and the minimal functional remnant size is unknown. New intraoperative imaging technologies allow improved remnant size and perfusion assessment. Fluorescence imaging and contrast-enhanced intraoperative CT showed congruent results in evaluation of perfusion. Intraoperative imaging can help to visualize the remnant vascular supply in partial adrenalectomy. Intraoperative assessment of perfusion may foster maximal functional tissue preservation in bilateral adrenal pathologies and procedures.

Laser ablation in biliary tree: analysis of the intraductal and superficial thermal effects during the treatment

The treatment of choice for the unresectable cholangiocarcinoma is based on biliary decompression procedures. Despite stent placement is the standard of care, it is related to well-known complications. Hence, alternative techniques were proposed. Ideally, they should guarantee an adequate intraductal disobstruction, without injuring the surrounding tissues.This pre-clinical study aims to investigate the thermal effects of the laser ablation (LA) in the biliary tree, in terms of intraductal and surrounding tissue temperature achieved with different laser settings. The common bile ducts (in their upper and lower portions) of two pigs were ablated for 6 minutes with a diode laser at 3 W and 5 W. A custom-made laser applicator was used to obtain a circumferential ablation within the ducts. The intraductal temperature (T_id) was monitored by means of a fiber Bragg grating (FBG) sensor, while an infrared thermal camera monitored the T distribution in the surrounding tissues (T_sup). A maximum T difference of 65 °C and 57 °C was evidenced between the two power settings for the T_id measured in the upper and lower ducts, respectively. The mean difference between T_id and the averaged T_sup values was evaluated. At 5 W, a difference of 37±3 °C and 44±10 °C were obtained for the upper and lower ducts, respectively. At 3 W, a T difference of 2±1 °C was obtained for the upper biliary duct, while a difference of 8±1 °C was documented for the lower duct. Based on the results obtained in this preliminary study, the possibility to equip the laser probe with temperature sensor can improve the control and the safety of the procedure; this solution will guarantee the monitoring of the treatment while preserving the lumen and the surrounding structures.

Hybrid transgastric approach for the treatment of gastroesophageal junction pathologies

Flexible endoscopy has evolved to the point that it includes many endoluminal procedures that once required open or laparoscopic surgery, for instance, antireflux surgery, pyloromyotomy, mucosal and submucosal tumor resections, and even full-thickness resection. However, these procedures remain technically demanding due to flexible technology issues: difficult imaging, limited energy devices, lack of staplers, unsatisfactory suturing abilities, and so on. Transgastric laparoscopy or hybrid laparoscopy/flex endoscopy has been described for almost two decades as an alternative to a pure endoluminal approach, mainly for pancreatic pseudocyst drainage and full-thickness and mucosal resection of various lesions. The approach has never been widely adopted mostly due to cumbersome and difficult to maintain methods of gastric access. We propose to expand the indications of transgastric laparoscopy by using novel endoscopically placed ports to replicate endoscopic procedures particularly in the difficult to access proximal stomach such as endoluminal antireflux surgery. Under general anesthesia, five female pigs (mean weight: 27.6 kg) had endoscopic placement of 3, 5 mm intragastric ports (Endo-TAGSS, Leakwood KS, USA) using a technique similar to percutaneous endoscopic gastrostomy. A 5-mm laparoscope was used for visualization. Laparoendoscopic-assisted plication of the gastroesophageal junction (GEJ) was performed using 3-0 interrupted sutures (Polysorb®, Covidien, Mansfield, MA, USA). A functional lumen imagine probe (EndoFLIP®, Crospon, Inc., Galway, Ireland) was used to measure diameter, cross sectional area (CSA), distensibility, and compliance of GEJ before and after intervention. Once the TAGSS ports were removed, the gastrotomies were closed by using endoscopic over-the-scope clips. At the end of the procedure, animals were euthanized. Five laparoendoscopic-assisted endoluminal plications were performed. The mean operative time was 65.6 min (Endoscopic evaluation: 3.2 min, TAGSS Insertion: 11 min, EndoFLIP evaluation + GEJ Plication: 43.25 min, gastric wall closure: 15 minutes). In all cases, this technique was effective and allowed to achieve an adequate GEJ plication by endoscopic grading and EndoFLIP measurements. Median pre-plication GEJ diameter (D) and median pre-plication GEJ cross-sectional area (CSA) were 11.42 mm (8.6-13.6 mm) and 104.8 mm2 (58-146 mm2). After the procedure, these values were decreased to 6.14 mm (5.7-6.6 mm) and 29.8 mm2 (25-34 mm2) respectively (p = 0.0079). Median pre-plication distensibility (d) and compliance (C) were 7.87 mm2/mmHg (2.4-22.69 mm2/mmHg) and 190.56 mm3/mmHg (70.9-502.8 mm3/mmHg). After the procedure, these values decreased to 1.5 mm2/mmHg (0.7-2.2 mm2/mmHg) and 52.17 mm3/mmHg (21.9-98.7 mm3/mmHg) respectively (p = 0.0317). No intraoperative events were observed. Endoscopically, all valves were felt to be transitioned from a Hill grade 3 (normal state for the animal model) to a Hill grade 1 at the procedure completion. A hybrid laparoendoscopic approach is a feasible alternative for performing intragastric procedures with the assistance of conventional laparoscopic instruments; especially in cases where the intervention location limits the access to standard endoscopy or where endoscopic technology is inadequate. Further evaluation is planned in survival models and clinical trials.

Robotic-assisted stereotactic real-time navigation: initial clinical experience and feasibility for rectal cancer surgery

BACKGROUND

Real-time stereotactic navigation for transanal total mesorectal excision has been demonstrated to be feasible in small pilot series using laparoscopic techniques. The possibility of real-time stereotactic navigation coupled with robotics has not been previously explored in a clinical setting.

METHODS

After pre-clinical assessment, and configuration of a robotic-assisted navigational system, two patients with locally advanced rectal cancer were selected for enrollment into a pilot study designed to assess the feasibility of navigation coupled with the robotic da Vinci Xi platform via TilePro interface. In one case, fluorescence-guided surgery was also used as an adjunct for structure localization, with local administration of indocyanine green into the ureters and at the tumor site.

RESULTS

Each operation was successfully completed with a robotic-assisted approach; image-guided navigation provided computed accuracy of ± 4.5 to 4.6 mm. The principle limitation encountered was navigation signal dropout due to temporary loss of direct line-of-sight with the navigational system's infrared camera. Subjectively, the aid of navigation assisted the operating surgeon in identifying critical anatomical planes. The combination of fluorescence with image-guided surgery further augmented the surgeon's perception of the operative field.

CONCLUSIONS

The combination of stereotactic navigation and robotic surgery is feasible, although some limitations and technical challenges were observed. For complex surgery, the addition of navigation to robotics can improve surgical precision. This will likely represent the next step in the evolution of robotics and in the development of digital surgery.

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.

Electronic supplementary material

The online version of this article (10.1007/s00464-018-6086-3) contains supplementary material, which is available to authorized users.

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.

Effects of Nd:YAG laser for the controlled and localized treatment of early gastrointestinal tumors: Preliminary in vivo study

Endoscopic submucosal dissection (ESD) is a minimally invasive technique allowing for the removal of early gastrointestinal (GI) tumors, widely considered as a valid alternative to conventional surgery. However, ESD is technically demanding, and potentially severe complications, such as bleeding and perforation, may occur. Energy-based techniques (e.g., radiofrequency ablation) might offer a potential alternative to ESD. However, their use mandates the ability to predict the damage induced and to identify a "signature" of the complete ablation, without the need for a physical specimen. Ideally, an energy-based procedure should be tunable in order to limit the ablation to the superficial layers, namely mucosa (M) and submucosa (SM), without injuring the muscularis propria (MP), thereby minimizing GI perforation. This experimental study aims to investigate thermal damage induced by Nd:YAG laser on the gastric wall, at different laser settings such as power (P) and time (t). Laser ablation was performed on the stomach wall of 6 Wistar rats. Two powers (2.5W and 1.0W) and 3 exposure times (12s, 6s and 2s) were tested, for a total of 30 ablations. Histological analysis allowed to assess thermal damage, in terms of damage depth (DD) and identification of involved layers. The ratio (R) between DD and the total depth (TD) of target layers (M+SM) was used as an index to evaluate the effectiveness of laser settings. At P=2.5W, MP was damaged (R>1) in the majority of cases (11/15). At P=1.0W, MP was preserved in all tests (R<;1), and rarely (4/15) did the damage reach the whole SM (R=1). Histopathological analysis evidenced that tissue damage was strongly related to the variable tissue thickness. These preliminary results seem to support the fact that endoscopic tunable laser ablation is feasible with a consistent damage/power correlation. Further tests are required to optimize the settings for applications on early GI tumors.

Novel carbon fiber probe for temperature monitoring during thermal therapies

Thermal treatments are a valid clinical option in the management of several solid tumors. The difficulties to perform an accurate prediction improve the selectivity of the treatment effects represent the main hurdles in the spread of these techniques. Among other solutions, thermometric techniques are gaining acceptance in monitoring the effects of thermal treatments because they provide a clear end-point to obtain the complete removal of cancer without damaging the surrounding healthy tissue. This paper proposes a custom needle-like probe made of carbon fibers to embed seven fiber Bragg grating (FBG) sensors. This tool aims at a multiple points monitoring the tissue temperature during the thermal procedures, streamlining the FBG sensors insertion within the organ. After the description of the probe manufacturing, we reported the calibration of the seven sensors embedded within the probe, their step response, and the feasibility assessment of the probe for temperature monitoring during laser ablation on animal model (both in vivo and ex vivo). Results show that the proposed probe is easily maneuverable by the clinician, the sensors have a linear response with the temperature and a short step response; moreover, the probe allows measuring the temperature in seven points of the tissue; finally, it can be used during CTand MR-guided procedures without causing any artifact to the images. Thanks to these features the probe may be an useful solution to improve the safety and the outcomes of minimally invasive thermal ablation procedures, so to spread these procedures in the clinical field.

Randomized trial of Roux-en-Y gastric bypass versus sleeve gastrectomy in achieving excess weight loss

Background

Robust data on quality of life (QoL) after different techniques of bariatric surgery are sparse. This RCT compared excess weight loss (EWL) and QoL after sleeve gastrectomy versus Roux-en-Y gastric bypass (RYGB).

Methods

Obese patients were assigned randomly to RYGB or sleeve gastrectomy. The primary outcome measure was EWL. Secondary outcomes included QoL, co-morbidity, adverse events, vitamin and glycolipid status. QoL was assessed before and annually after surgery, using the Moorehead–Ardelt Quality of Life Questionnaire II (M-A-QoLQII) and Gastrointestinal Quality of Life Index (GIQLI).

Results

One hundred patients were enrolled, 45 in the RYGB group and 55 in the sleeve gastrectomy group. Mean postoperative EWL at 1, 2, 3 and 5 years was 80·4, 79·8, 83·0 and 74·8 per cent respectively after RYGB, and 83·0, 77·8, 66·3 and 65·1 per cent after sleeve gastrectomy (P = 0·017). Mean M-A-QoLQII score before surgery and at 1, 2, 3 and 5 years after operation was 0·5, 1·6, 1·7, 2·1 and 1·4 respectively after RYGB, and 0·3, 1·7, 1·5, 1·5 and 1·2 after sleeve gastrectomy. Mean GIQLI score before and at 1, 2, 3, 5 years after RYGB was 96·4, 113·8, 113·3, 113·4, 111·7, compared with 90·7, 113·9, 114·5, 113·1 and 113·0 for sleeve gastrectomy. The improvement was significant compared with preoperative values (P &lt; 0·001 for M-A-QoLQII and GIQLI), with no difference between groups (P = 0·418 and P = 0·323 respectively). RYGB resulted in higher readmission rates (P = 0·002) and length of hospital stay (P = 0·006) than sleeve gastrectomy.

Conclusion

RYGB and sleeve gastrectomy resulted in equivalent, long-standing QoL improvement. RYGB resulted in more stable weight loss but was associated with higher readmission rates. Registration number: NCT02475590.

Multipoint temperature monitoring in liver undergoing computed tomography-guided radiofrequency ablation with fiber Bragg grating probes

In this work, we investigated the temperature increment experienced by biological tissue during radiofrequency ablation (RFA). The measurements were performed by using two custom-made thermal probes based on fiber optic sensors (fiber Bragg gratings, FBGs). The two probes embed a total of 9 FBGs. Experiments were performed during RFA of an ex vivo healthy porcine liver. The RFA heating module was equipped with 5 thermocouples. Results show that the temperature increment close to the applicator (i.e., 0.6 cm-0.7 cm) reaches the temperature which is set as a target on the RFA module (i.e., approximately 100 °C). The distance from the applicator also has an impact on the dynamics of the heating phenomenon: at short distances the tissue temperature reaches a steady state condition after a few minutes, on the other hand the sensors placed at a distance ≥2cm did not reach the steady-state conditions during the 14-minute procedure. The multipoint temperature monitoring, which uses sensors at several distances from the applicator, can provide useful information regarding the boundary of damaged volume. This approach can be combined with the monitoring temperature system embedded in the heating equipment, to better control the damaged volume, and to improve the treatment outcomes.

Robotic Lymphadenectomy During Pancreatoduodenectomy with First Superior Mesenteric Artery Dissection

BACKGROUND

An expert consensus meeting had defined the standard lymphadenectomy during pancreatoduodenectomy for an adenocarcinoma of the head of the pancreas. There is a controversy regarding the possibility to perform this optimal lymphadenectomy by minimally invasive approach.

PATIENTS

The patient was a 68-year-old man with the diagnosis of an adenocarcinoma of the head of the pancreas. The 3D reconstructions evidenced the existence of a right hepatic artery.

TECHNIQUE

The patient was positioned in the French position with the assistant between the legs and the robot at the head. Five trocars were used; the camera was introduced through the umbilicus trocar. The operation began with a peritoneal and liver exploration, and with an inter-aortico-caval picking. Because lymph nodes were noninvaded, pancreatoduodenectomy was decided with the first dissection of the superior mesenteric artery helped with a hanging maneuver. The right hepatic artery was dissected. Each structure of the hepatic pedicle was skeletonized. The camera was switched to the right side. The first jejunal loop was divided with a stapler. The specimen was totally mobilized en bloc, freed from the portal vascular axis with a dissection of the right border of the coeliac trunk. The pancreas was divided. At the end of the dissection, the different arterial and venous structures were skeletonized with a resection of the lymph node group 5-6-8_a-12_a,b,c-13_a,b-14_a,b-17_a,b. Pathology confirmed R0 resection for a well-differentiated pancreatic adenocarcinoma graded pT3N1 (5/20).

CONCLUSIONS

Robotic pancreatoduodenectomy could be performed with an optimal standard lymphadenectomy as recommended by the expert consensus.

Robotic pancreaticoduodenectomy and distal pancreatectomy: State of the art

Over recent years, minimally invasive pancreatic resections have increasingly been reported in the literature. Even though pancreatic surgery is still considered a challenge for surgeons due to its technical difficulties and high morbidity, the development and spread of robotic surgery has highlighted a new interest, which has induced a rapid spread of robotic approaches for pancreatic resections. This study presents a systematic review of the literature regarding robotic pancreaticoduodenectomy and distal pancreatectomy in order to assess the safety and feasibility of robotic pancreatic resection.

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.

Robotic surgery

BACKGROUND

Proficiency in minimally invasive surgery requires intensive and continuous training, as it is technically challenging for unnatural visual and haptic perceptions. Robotic and computer sciences are producing innovations to augment the surgeon's skills to achieve accuracy and high precision during complex surgery. This article reviews the current use of robotically assisted surgery, focusing on technology as well as main applications in digestive surgery, and future perspectives.

METHODS

The PubMed database was interrogated to retrieve evidence-based data on surgical applications. Internal and external consulting with key opinion leaders, renowned robotics laboratories and robotic platform manufacturers was used to produce state-of-the art business intelligence around robotically assisted surgery.

RESULTS

Selected digestive procedures (oesophagectomy, gastric bypass, pancreatic and liver resections, rectal resection for cancer) might benefit from robotic assistance, although the current level of evidence is insufficient to support widespread adoption. The surgical robotic market is growing, and a variety of projects have recently been launched at both academic and corporate levels to develop lightweight, miniaturized surgical robotic prototypes.

CONCLUSION

The magnified view, and improved ergonomics and dexterity offered by robotic platforms, might facilitate the uptake of minimally invasive procedures. Image guidance to complement robotically assisted procedures, through the concepts of augmented reality, could well represent a major revolution to increase safety and deal with difficulties associated with the new minimally invasive approaches.

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.

MAGNAMOSIS IV: magnetic compression anastomosis for minimally invasive colorectal surgery

BACKGROUND AND STUDY AIMS

MAGNAMOSIS forms a compression anastomosis using self-assembling magnetic rings that can be delivered via flexible endoscopy. The system has proven to be effective in full-thickness porcine small-bowel anastomoses. The aim of this study was to show the feasibility of the MAGNAMOSIS system in hybrid endoscopic colorectal surgery and to compare magnetic and conventional stapled anastomoses.

METHODS

A total of 16 swine weighing 35 - 50 kg were used following animal ethical committee approval. The first animal was an acute model to establish the feasibility of the procedure. The subsequent 15 animals were survival models, 10 of which underwent side-to-side anastomoses (SSA) and 5 of which underwent end-to-side (ESA) procedures. Time to patency, surveillance endoscopy, burst pressure, compression force, and histology were assessed. Histology was compared with conventional stapled anastomoses. Magnetic compression forces were measured in various anastomosis configurations.

RESULTS

Colorectal anastomoses were performed in all cases using a hybrid NOTES technique. The mean operating time was 71 minutes. Mean time to completion of the anastomosis was similar between the SSA and ESA groups. Burst pressure at 10 days was greater than 95 mmHg in both groups. One complication occurred in the ESA group. Compression force among various configurations of the magnetic rings was significantly different (P < 0.05). Inflammation and fibrosis were similar between magnetic SSA and conventional stapled anastomoses.

CONCLUSION

MAGNAMOSIS was feasible in performing a hybrid NOTES colorectal anastomosis. It has the advantage over circular staplers of precise endoscopic delivery throughout the entire colon. SSA was reliable and effective. A minimum initial compression force of 4 N appears to be required for reliable magnetic anastomoses.

Appendicitis/diverticulitis: minimally invasive surgery

Complicated intra-abdominal infections such as acute appendicitis and complicated diverticulitis represent both diagnostic and therapeutic challenges. Both diseases, although different in many ways, are caused by the obstruction of a blind pouch leading to inflammation, abscesses, and perforation of surrounding tissues. For many decades, acute appendicitis was managed through a conventional surgical incision in the right iliac fossa. As for other diseases, there is a significant tendency to propose less invasive treatments. For many teams, laparoscopy, which leads to less postoperative pain, a shorter hospital stay, and a quicker recovery, represents the standard of care for appendectomy. For selected cases, a medical approach can be proposed with satisfactory outcomes. Additionally, the management of complicated diverticulitis is also quickly moving towards less invasive procedures than the deleterious '3-phase surgery', which is Hartmann's procedure, followed by reversal protected with a stoma, and finally stoma closure. Benefiting from the evolution of antimicrobial therapy and interventional radiology, many complicated cases classified as Hinchey stage I and Hinchey stage II complicated diverticulitis are now treated medically. CT images allow the identification of patients requiring radiological drainage of localized abscesses or collections over 5 cm in size. Patients with Hinchey stage III sigmoiditis may benefit from an initial laparoscopic exploration allowing, in some cases, a conservative nonresective approach that will prevent laparotomy and stoma. Major resection leading to temporary or definitive stoma is usually indicated for stage IV complications and is required only in exceptional cases. Although a surgical intervention can be the definitive treatment for complicated intra-abdominal infections, multidisciplinary management including radiology, medical treatment, and laparoscopic surgery may limit the severe consequences of an acute surgical approach in patients suffering from complicated appendicitis and diverticulitis. Today, the ultimate goal of acutely infected abdomen management is to reduce hospital stay, disability, and numerous operations for these patients.

Small bowel exploration and resection using single-port surgery: a safe and feasible approach

AIM

The aim of this study is to demonstrate the efficacy of wireless capsule endoscopy for preoperative identification of bleeding sources and/or small bowel tumours in surgical patients and to evaluate the feasibility of single-port surgery in the treatment of such pathologies.

METHOD

Five patients presenting with obscure gastrointestinal bleeding or/and mild small bowel obstruction were investigated to diagnose and localize the bleeding source or tumour using capsule endoscopy imaging, and, if necessary, with other investigative modalities. All patients were operated on using single-port surgery for small bowel exploration, lesion confirmation, small bowel resection and anastomosis.

RESULTS

Small bowel pathology was successfully detected by video capsule endoscopy in three of four patients, and was further substantiated by contrast CT, double-balloon endoscopy or enteroclysis. Complete small bowel exploration, intra-operative identification and oncological resection of the involved segment and anastomosis (intracorporeal and extracorporeal) was successfully performed in all five patients using single-port access without any complication, morbidity or mortality.

CONCLUSION

This study demonstrates the feasibility and safety of single-port small bowel resection performed after a high-quality preoperative localization of the tumour.

Laparoscopic extraperitoneal colostomy in elective abdominoperineal resection for cancer: a single surgeon experience

AIM

Parastomal herniation of end colostomies can be chronically debilitating for patients and a difficult problem to treat. To prevent parastomal hernia (PSH) formation an extraperitoneal colostomy (EPC) approach has been developed in open colorectal surgery and some studies have suggested a potential advantage to this approach. Here we describe our technique of laparoscopic extraperitoneal stoma formation and present our experience to date.

METHODS

We performed a retrospective analysis of consecutive patients undergoing a laparoscopic abdominoperineal resection between March 1999 and March 2011. We performed the EPC technique as follows: under laparoscopic guidance, a smooth tip instrument was used to gently separate the peritoneum from the posterior aponeurotic plane to create an extraperitoneal tunnel running from the skin incision to the left flank of the abdominal cavity to join the previously dissected paracolic gutter. The colon was exteriorized and the position was checked to ensure the absence of torsion or kinking.

RESULTS

Twenty-two patients underwent a standard laparoscopic abdominoperineal resection with total mesorectal excision. Colostomy was constructed extraperitoneally (EPC) or transperitoneally (TPC) in 12 and 10 patients respectively. There were five complications requiring operative intervention: two stomal necrosis and one surgical site infection in the TPC group and two small bowel occlusions in the EPC group. Four patients from the TPC group developed PSH at 24, 36, 48 and 72 months respectively while there were no cases of PSH in the EPC group.

CONCLUSION

Extraperitoneal laparoscopic colostomy showed a potential reduction of PSH in our series of patients.

Duodenal duplication cyst: a potentially malignant disease

BACKGROUND

Duodenal duplication cysts constitute a rare congenital anomaly of the gastrointestinal tract. A recent meta-analysis of the literature between 1999 and 2009 reported a total of 47 cases of duodenal duplication cysts.1 These abnormalities are mostly diagnosed in infancy and childhood. In rare cases, they can remain asymptomatic until adulthood, and 38 % of patients are diagnosed after age 20 years.1 (,) 2 Duodenal duplication cysts are generally benign lesions; nevertheless, three cases of malignant tumours arising inside have been reported.3 (-) 5

METHODS

In this multimedia article, we illustrated the case of an 18 year-old female patient presenting with recurrent episodes of mild pancreatitis. MRI revealed a cystic structure measuring 2.5 cm in diameter located in the duodenal wall next to the papilla of Vater. Endoscopic ultrasound showed a cystic lesion cephalad to the papilla, protruding into the duodenal lumen. Endoscopic retrograde cholangiopancreatography was not feasible due to the dislocation of the papilla, whose macroscopic aspect was normal. To further elucidate the anatomical relations, 3D reconstruction of the MRI images was performed. There was neither dilatation of the biliary tract nor a visible communication between the common bile duct and the cystic structure. The pancreatic duct also was at distance. Those findings were suggestive of a duodenal duplication. Nevertheless, the differential diagnosis6 of a choledochocele (Todani III) could not be formally excluded. Indication for surgical resection was symptomatic disease in a context of potential malignancy.

RESULTS

By right subcostal incision (video), surgical exploration revealed a soft tissue mass palpable at the second portion of the duodenum. Following duodenotomy, the mucosa was incised cephalad to the papilla of Vater, which could previously be localized by methylene blue injection by a catheter inserted into the cystic duct. The cystic structure was dissected and no communication between the cyst and the biliary tract was individualized. The final diagnosis was made by histological examination showing duodenal duplication. There was neither heterotopic gastric mucosa nor excreto-biliary epithelial layer. There were no signs of malignancy. The postoperative course was marked by hematemesis externalised by the nasogastric tube. We reintervened at postoperative day 2 to ensure hemostasis. A clot was removed from the area of duodenal mucosa without any visible active bleeding. Further recovery was uneventful; the patient was discharged at postoperative day 10 and is actually asymptomatic.

DISCUSSION

The ideal treatment of duodenal duplication cysts is complete surgical resection.7 Due to proximity to the bilio-pancreatic duct, total resection sometimes requires pancreaticoduodenectomy. This major surgical procedure entails the disadvantages of high morbidity and mortality with poor quality of life. In our opinion, this procedure should remain an ultimate option. Less invasive approaches have been proposed, including partial resection or internal derivation.7 Marsupialization is a surgical approach that has been accomplished even endoscopically.1 Nevertheless, these techniques do not provide total resection and leave the risk of degenerescence. As cases of malignancy are reported, we decided to realize a complete surgical excision of the lesion. Three-dimensional reconstruction of the biliary anatomy is an innovative procedure, which allowed us to show the absence of any communication between the cyst and either the common bile duct or the pancreatic duct.8 So, the surgical approach could be specified preoperatively ensuring the integrity of the common bile duct. Duplication cysts could be connected to the pancreaticobiliary ducts in about 29 %.1 Subsequent realization of a total surgical excision combined the advantages of complete resection with minimal invasiveness.

CONCLUSIONS

For relieving symptoms and preventing further complications, such as pancreatitis or malignant transformation, surgical resection of duodenal duplication cysts is indicated. In cases of difficulties to individualize the neighboring anatomical structures preoperatively, 3D reconstruction is a helpful approach to determine the surgical strategy. Enucleation allows a total excision while minimizing the adverse effects and therefore it is our treatment of choice for duodenal duplication cysts without communication.

Prospective experimental study of transrectal viscerotomy closure using transanal endoscopic suture vs. circular stapler: a step toward NOTES

BACKGROUND AND STUDY AIM

Endoluminal full-thickness closure of the rectal wall is critical in emerging procedures including endoscopic submucosal dissection and transrectal natural orifice transluminal endoscopic surgery (NOTES). This study aimed to compare manual suture using the transanal endoscopic operation platform (TEO; Karl Storz, Tüttlingen, Germany) with the end-to-end anastomosis hemorrhoid circular stapler (EEA; Covidien, Dublin, Ireland) for closure of the rectal viscerotomy during transrectal NOTES segmental colectomy.

MATERIALS AND METHODS

A total of 12 swine underwent transrectal hybrid NOTES partial colectomies. Animals were divided into two groups according to the viscerotomy closure technique: 1) TEO manual suture; 2) EEA circular stapler closure.

RESULTS

Mean (± SD) viscerotomy closure time was 67.5 ± 59.5 minutes and 31.5 ± 19.6 minutes for TEO and EEA, respectively. There was one conversion to laparoscopy in the TEO group and a misfiring in the EEA group that required a TEO salvage suture. There was one positive air-leak test in each group. Peritoneal fluid collected at the end of the procedure tested positive for bacterial contamination in all cases. A mild stenosis was present in 4 /6 viscerotomies (67 %) in the TEO group and in 1/6 (17 %) in the EEA group on endoscopic control. Inflammatory changes were mild in 3/5 (60 %) and 4/5 (80 %) viscerotomies in the TEO and EEA groups, respectively, whereas severe inflammation was found in 2/5 (TEO) and 1 /5 (EEA).

CONCLUSION

Transrectal viscerotomy closure using the EEA circular stapler technique is feasible, easy to perform, and histologically comparable to suture closure through a TEO platform. It may offer an attractive alternative for NOTES segmental colectomies and endoscopic resections.

Minimally invasive surgical treatment of sigmoid diverticulitis

INTRODUCTION

Diverticular disease is very common in Western societies. However, there is a trend towards reducing indications for the surgical management of diverticulitis. Minimally invasive surgery offers many potential advantages to patients in the treatment of diverticulitis and may optimise surgical indications.

METHODS

A systematic literature review of minimally invasive techniques was carried out for the treatment of diverticulitis. The following techniques were reviewed: laparoscopic, single-port, natural orifice specimen extraction, natural orifice transluminal endoscopic surgery and laparoscopic lavage for the treatment of diverticulitis.

RESULTS

In total, 2,050 minimally invasive cases were reviewed. Of all the different minimally invasive techniques published regarding the management of diverticular disease, laparoscopic surgery is the only technique that has undergone the rigours of randomised controlled trials. The documented benefits are less blood loss, less pain and analgesic requirements, a reduction in major complications, a reduction in the frequency of drain usage, a reduction in the duration of postoperative ileus and shorter hospital stay. However, operative time does appear to be longer. It has also been demonstrated that elective laparoscopic surgery results in improved quality of life and social functioning.

CONCLUSION

Minimally invasive surgery for the treatment of diverticular disease appears feasible and safe. The result of future randomised trials will more clearly define the role each minimally invasive technique will play in the future.

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.

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.

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.

Transanal extraction of the specimen during laparoscopic colectomy

AIM

To assess the current state of the art of transanal specimen extraction in colonic resections.

METHOD

A systematic literature search was conducted including the terms 'transrectal or transanal specimen extraction', 'Natural Orifice Specimen Extraction' and 'laparoscopic colectomy' for the period from 1955 to May 2011. Exclusion criteria were abdomino-perineal resections, pull-through technique, experimental studies and paediatric population.

RESULTS

Nineteen studies met the inclusion criteria, representing 154 patients. The overall postoperative complication rate was 10%. The risks of peritoneal contamination and sphincter dysfunction were evaluated by a single study of each.

CONCLUSION

Transanal extraction is a feasible option to minimize incisions in colorectal surgery.

Technical aspects and outcome of a standardized full laparoscopic approach to the reversal of Hartmann's procedure in a teaching centre

AIM

Laparoscopic reversal of Hartmann's procedure is technically demanding. We evaluated the technical aspects and outcome of a standardized approach in a single centre and examined the feasibility of including this into training curricula.

METHOD

The procedure entails a laparoscopy for adhesiolysis and identification and mobilization of the rectal stump. Mobilization of the splenic flexure is performed if necessary, and a colorectal anastomosis is fashioned after introduction of the stapler anvil via the colostomy with intra-abdominal positioning and delivery into the proximal colonic segment to be anastomosed. The stoma is excised as the last step in the operation.

RESULTS

Forty-two patients underwent the procedure over an 8-year period with either an expert (n=21) or trainee under expert mentorship (n=21) as first operator. Intra-operative data and postoperative outcomes were evaluated by retrospective review of clinical charts and theatre records. There was a 9.5% conversion rate and 0% mortality. One patient suffered a ureteric injury, while postoperative surgical complications occurred in 7 patients (including one clinical anastomotic leakage). The mean operative time was 117 min. There was no significant difference in intra operative technical parameters or postoperative clinical consequences between procedures performed by a trained surgeon or by a trainee under mentorship.

CONCLUSION

Adherence to a standardized operative protocol and expert mentorship allows this technically demanding operation to be associated with low conversion and complication rates. The absence of any difference between procedures performed by a trainee or trained surgeon suggests that the operation can be included in training programmes for laparoscopic surgery.

Transvaginal specimen extraction in colorectal surgery: current state of the art

BACKGROUND

The expected benefit of transvaginal specimen extraction is reduced incision-related morbidity.

OBJECTIVES

A systematic review of transvaginal specimen extraction in colorectal surgery was carried out to assess this expectation.

SEARCH STRATEGY

The following keywords, in various combinations, were searched: NOSE (natural orifices specimen extraction), colorectal, colon surgery, transvaginal, right hemicolectomy, left hemicolectomy, low anterior resection, sigmoidectomy, ileocaecal resection, proctocolectomy, colon cancer, sigmoid diverticulitis and inflammatory bowel diseases.

SELECTION CRITERIA

SELECTION CRITERIA included large bowel resection with transvaginal specimen extraction, laparoscopic approach, human studies and English language. Exclusion criteria were experimental studies and laparotomic approach or local excision. All articles published up to February 2011 were included.

RESULTS

Twenty-three articles (including a total of 130 patients) fulfilled the search criteria. The primary diagnosis was colorectal cancer in 51% (67) of patients, endometriosis in 46% (60) of patients and other conditions in the remaining patients. A concurrent gynaecological procedure was performed in 17% (22) of patients. One case of conversion to laparotomy was reported. In two patients, transvaginal extraction failed. In left- and right-sided resections, the rate of severe complications was 3.7% and 2%, respectively. Two significant complications, one of pelvic seroma and one of rectovaginal fistula, were likely to have been related to transvaginal extraction. The degree of follow up was specified in only one study. Harvested nodes and negative margins were adequate and reported in 70% of oncological cases.

CONCLUSION

Vaginal extraction of a colorectal surgery specimen shows potential benefit, particularly when associated with a gynaecological procedure. Data from prospective randomized trials are needed to support the routine use of this technique.

Laparoscopic resection with transanal specimen extraction for sigmoid diverticulitis

BACKGROUND

This prospective study evaluated the technical aspects and microbiological consequences of laparoscopic resection with transanal specimen extraction and per ano transcolonic stapler anvil insertion in patients requiring elective operation for previous diverticulitis.

METHODS

Laparoscopic sigmoid colectomy was performed with three ports, and specimen extraction carried out transanally through a complete opening of the rectal stump. A triple-stapled anastomosis restored colonic continuity. Systematic intraoperative bacteriological sampling was performed. Intraoperative data as well as microbiological and postoperative outcomes were evaluated prospectively.

RESULTS

Sixteen consecutive patients were studied over a 6-month period. All procedures were technically satisfactory, with a mean(s.d.) operating time of 120·9(41·9) min. No conversion or additional access was required. Four of the 16 patients developed complications, but none required intervention. Although polybacterial growth was present in all peritoneal culture samples, no infection-related complications were observed. Two patients had an extended course of perioperative antibiotic cover owing to overt peritoneal cavity contamination during surgery, and in two further patients antibiotics were instituted empirically following the development of postoperative fever alone.

CONCLUSION

Transanal specimen extraction in addition to per ano transcolonic stapler anvil insertion allows laparoscopic sigmoid resection to be performed with just three ports. Although intraperitoneal bacterial contamination occurs, this does not appear to translate into infectious morbidity.

A cost effective simulator for education of ultrasound image interpretation and probe manipulation

Ultrasonography is the lowest cost no risk medical imaging technique. However, reading an ultrasonographic (US) image as well as performing a good US probe positioning remain difficult tasks. Education in this domain is today performed on patients, thus limiting it to the most common cases. In this paper, we present a cost effective simulator that allows US image practice and realistic probe manipulation from CT data. More precisely, we tackle the issue of providing a realistic interface for the probe manipulation with a basic haptic feedback.

Recent advances in liver imaging

Liver surgery remains a difficult challenge in which preoperative data analysis and strategy definition may play a significant role in the success of the procedure. Medical image processing led to a major improvement of patient care by guiding the surgical gesture. From this initial data, new technologies of virtual reality and augmented reality can increase the potential of such images. The 3D modeling of the liver of patients from their CT scan or MRI thus allows an improved surgical planning. Simulation allows the procedure to be simulated preoperatively and offers the opportunity to train the surgical gesture before carrying it out. These three preoperative steps can be used intraoperatively thanks to the development of augmented reality, which consists of superimposing the preoperative 3D modeling of the patient onto the real intraoperative view of the patient and his/her organs. Augmented reality provides surgeons with a transparent view of the patient. This facilitated the intraoperative identification of the vascular anatomy and the control of the segmental arteries and veins in liver surgery, thus preventing intraoperative bleeding. It can also offer guidance due to the virtual improvement of their real surgical tools, which are tracked in real-time during the procedure. During the surgical procedure, augmented reality, therefore, offers surgeons a transparent view of their patient, which will lead to the automation of the most complex maneuvers. The new ways of processing and analyzing liver images have dramatically changed the approach to liver surgery.

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.

Surgical access to the adrenal gland: the quest for a "no visible scar" approach

Surgery of the adrenal glands has various approaches and remains technically challenging. Many different techniques have been used to decrease morbidity. The most important one is probably laparoscopy which has already quite dramatically improved clinical outcome. The second one is the introduction of posterior endoscopic approach (retroperitoneoscopy), which entirely preserves peritoneal integrity. This concept seems to us to be a fundamental in surgery of the retroperitoneum. Recently, new developments have emerged in the field of abdominal surgery. The most radical concept, known as Natural Orifice Transluminal Endoscopic Surgery (NOTES), consists of the introduction of both endoscope and working instruments through natural orifices in order to eliminate skin incisions and their associated morbidities. Although transperitoneal adrenalectomy has previously been reported in a porcine model, here we report our initial experiences of extra-peritoneal transvaginal NOTES approach of the retroperitoneum, focused on the field of adrenal surgery in both porcine and cadaver models. Whether clinical applications will ultimately be derived of this concept is still not clear certainly it raises new possibilities for interesting developments.

Comparison of visual tracking algorithms on in vivo sequences for robot-assisted flexible endoscopic surgery

Flexible endoscopes are used in many diagnostic and interventional procedures. Physiological motions may render the physician's task very difficult to perform. Assistance could be achieved by using motorized endoscopes and real-time visual tracking algorithm to automatically follow a selected target. In order to control the motors, one needs to have an accurate estimation of the motion of the target in the endoscopic view, which requires an efficient tracking algorithm. In this paper, we compare tracking algorithms on various in vivo targets in order to assess their behavior under different conditions. The study shows that among the difficulties which arise when tracking an in vivo target, the change of illumination is paramount. Nevertheless, some algorithms, with minor modifications and without a priori knowledge about the target, achieve very good results.