Consensus conference statement on fluorescence-guided surgery (FGS) ESSO course on fluorescence-guided surgery

BACKGROUND

Fluorescence-guided surgery (FGS) has emerged as an innovative technique with promising applications in various surgical specialties. However, clinical implementation is hampered by limited availability of evidence-based reference work supporting the translation towards standard-of-care use in surgical practice. Therefore, we developed a consensus statement on current applications of FGS.

METHODS

During an international FGS course, participants anonymously voted on 36 statements. Consensus was defined as agreement ≥70% with participation grade of ≥80%. All participants of the questionnaire were stratified for user and handling experience within five domains of applicability (lymphatics & lymph node imaging; tissue perfusion; biliary anatomy and urinary tracts; tumor imaging in colorectal, HPB, and endocrine surgery, and quantification and (tumor-) targeted imaging). Results were pooled to determine consensus for each statement within the respective sections based on the degree of agreement.

RESULTS

In total 43/52 (81%) course participants were eligible as voting members for consensus, comprising the expert panel (n = 12) and trained users (n = 31). Consensus was achieved in 17 out of 36 (45%) statements with highest level of agreement for application of FGS in tissue perfusion and biliary/urinary tract visualization (71% and 67%, respectively) and lowest within the tumor imaging section (0%).

CONCLUSIONS

FGS is currently established for tissue perfusion and vital structure imaging. Lymphatics & lymph node imaging in breast cancer and melanoma are evolving, and tumor tissue imaging holds promise in early-phase trials. Quantification and (tumor-)targeted imaging are advancing toward clinical validation. Additional research is needed for tumor imaging due to a lack of consensus.

European Association for Endoscopic Surgery (EAES) consensus on Indocyanine Green (ICG) fluorescence-guided surgery

BACKGROUND

In recent years, the use of Indocyanine Green (ICG) fluorescence-guided surgery during open and laparoscopic procedures has exponentially expanded across various clinical settings. The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference on this topic with the aim of creating evidence-based statements and recommendations for the surgical community.

METHODS

An expert panel of surgeons has been selected and invited to participate to this project. Systematic reviews of the PubMed, Embase and Cochrane libraries were performed to identify evidence on potential benefits of ICG fluorescence-guided surgery on clinical practice and patient outcomes. Statements and recommendations were prepared and unanimously agreed by the panel; they were then submitted to all EAES members through a two-rounds online survey and results presented at the EAES annual congress, Barcelona, November 2021.

RESULTS

A total of 18,273 abstracts were screened with 117 articles included. 22 statements and 16 recommendations were generated and approved. In some areas, such as the use of ICG fluorescence-guided surgery during laparoscopic cholecystectomy, the perfusion assessment in colorectal surgery and the search for the sentinel lymph nodes in gynaecological malignancies, the large number of evidences in literature has allowed us to strongly recommend the use of ICG for a better anatomical definition and a reduction in post-operative complications.

CONCLUSIONS

Overall, from the systematic literature review performed by the experts panel and the survey extended to all EAES members, ICG fluorescence-guided surgery could be considered a safe and effective technology. Future robust clinical research is required to specifically validate multiple organ-specific applications and the potential benefits of this technique on clinical outcomes.

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.

[Possibilities and perspectives of hyperspectral imaging in visceral surgery]

HyperSpectral Imaging (HSI) technology enables quantitative tissue analyses beyond the limitations of the human eye. Thus, it serves as a new diagnostic tool for optical properties of diverse tissues. In contrast to other intraoperative imaging methods, HSI is contactless, noninvasive, and the administration of a contrast medium is not necessary. The duration of measurements takes only a few seconds and the surgical procedure is only marginally disturbed. Preliminary HSI applications in visceral surgery are promising with the potential of optimized outcomes. Current concepts, possibilities and new perspectives regarding HSI technology together with its limitations are discussed in this article.

Hyperspectral imaging for thermal effect monitoring in in vivo liver during laser ablation

Thermal ablation is a minimally invasive technique used to induce a controlled necrosis of malignant cells by increasing the temperature in localized areas. This procedure needs an accurate and real-time monitoring of thermal effects to evaluate and control treatment outcome. In this work, a hyperspectral imaging (HSI) technique is proposed as a new and non-invasive method to monitor ablative therapy. HSI provides images of the target object in several spectral bands, hence the reflectance/absorbance spectrum for each pixel. This paper presents a preliminary and original HSI-based analysis of the thermal state in the in vivo porcine liver undergoing laser ablation. In order to compare the spectral response between treated and untreated areas of the organ, proper Regions of Interest (ROIs) were chosen on the hyperspectral images; for each ROI, the absorbance variation for the selected wavelengths (i.e., 630, 760, and 960nm, for deoxyhemoglobin, methemoglobin, and water respectively) was assessed. Results obtained during and after laser ablation show that the absorbance of the methemoglobin peaks increases up to 40% in the burned region with respect to the non-ablated one. Conversely, the relative change of deoxyhemoglobin and water peaks is less marked. Based on these results, absorbance threshold values were retrieved and used to visualize the ablation zone on the images. This preliminary analysis suggests that a combination of the absorbance information is essential to achieve a more accurate identification of the ablation region. The results encourage further studies on the correlation between thermal effects and the spectral response of biological tissues undergoing thermal ablation, for final clinical use.

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.

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.

Cardiovascular risk assessment between urban and rural population in Malaysia

INTRODUCTION

Cardiovascular disease (CVD) caused significant burden to Malaysia as it accounted for 36% of total deaths. This study aims to evaluate the burden of cardiovascular risk factors among Malaysian adult and assess the difference between urban and rural population in the selected communities.

METHODS

This study is part of the ongoing Prospective Urban Rural Epidemiology (PURE) database, whereby the baseline data were collected since June 2008. CVD risk was measured using INTERHEART risk score which comprised of eleven risk factors i.e. age and gender, family history of heart attack, smoking status, exposure to second hand smoke, diabetes mellitus, hypertension status, waist-hip ratio, self-reported stress, depression, dietary habits and physical activity status.

RESULTS

Majority of the studied participants had low cardiovascular risk (57%). Participants from rural area were generally older, had lower educational status, higher prevalence of smokers, obesity, hypertension, diabetes, and more likely to be depressed. In comparison, urbanites had lower physical activities and more likely to be stressful. Mean INTERHEART score among rural participants were higher, especially for male, in comparison to urbanite (11.5±5.83 vs. 10.01±5.74, p<0.001).

CONCLUSION

Contradict to common beliefs, participants in rural areas generally have higher cardiovascular risk factors compared to their urban counterparts. The rural population should be targeted for focused preventive interventions, taking account the socioeconomic and cultural context.

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.

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.

A multistrategic approach in the development of sourdough bread targeted towards blood pressure reduction

Rising prevalence of hypertension is pushing food industry towards the development of innovative food products with antihypertensive effects. The aim was to study the effect of reduced sodium content and 21% addition of wholemeal wheat sourdough (produced by Lactobacillus brevis CECT 8183 and protease) on proximate composition, γ-aminobutyric acid (GABA) and peptide content of wheat bread. Angiotensin converting enzyme I (ACE) inhibitory and antioxidant activities were also evaluated. Sodium replacement by potassium salt did not affect chemical composition and biological activities of bread. In contrast, GABA and peptides <3 kDa contents in sourdough bread (SDB) were 7 and 3 times higher, respectively, than the observed in control. ACE inhibitory and antioxidant activities of the peptide fraction < 3 kDa from SDB was 1.7 and 2.6-3.0 times higher than control. Therefore, the combination of reduced sodium content with enriched concentrations of bioactive compounds in bread making may provide interesting perspectives for development of innovative breads towards blood pressure reduction.

Subcellular distribution of melatonin receptors in human parotid glands

The hormone melatonin influences oral health through a variety of actions, such as anti-inflammatory, anti-oxidant, immunomodulatory and antitumour. Many of these melatonin functions are mediated by a family of membrane receptors expressed in the oral epithelium and salivary glands. Using immunoblotting and immunohistochemistry, recent studies have shown that the melatonin membrane receptors, MT1 and MT2, are present in rat and human salivary glands. To date, no investigation has dealt with the ultrastructural distribution of the melatonin receptors. This was the aim of the present study, using the immunogold method applied to the human parotid gland. Reactivity to MT1 and, with less intensity, to MT2 appeared in the secretory granules of acinar cells and in the cytoplasmic vesicles of both acinar and ductal cells. Plasma membranes were also stained, albeit slightly. The peculiar intracytoplasmic distribution of these receptors may indicate that there is an uptake/transport system for melatonin from the circulation into the saliva.

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.

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.

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.

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.

Altered Mesolimbic Dopamine System in THC Dependence

To explore the functional consequences of cannabinoid withdrawal in the rat mesolimbic dopamine system, we investigated the anatomical morphology of the mesencephalic, presumed dopaminergic, neurons and their main post-synaptic target in the Nucleus Accumbens. We found that TH-positive neurons shrink and Golgi-stained medium spiny neurons loose dendritic spines in withdrawal rats after chronic cannabinoids administration. Similar results were observed after administration of the cannabinoid antagonist rimonabant to drug-naïve rats supporting a role for endocannabinoids in neurogenesis, axonal growth and synaptogenesis. This evidence supports the tenet that withdrawal from addictive compounds alters functioning of the mesolimbic system. The data add to a growing body of work which indicates a hypodopaminergic state as a distinctive feature of the “addicted brain”.

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.

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.

[Surgical treatment of acute diverticulitis. Our experience]

The treatment of the acute diverticulitis is still a stimulating and complex problem sustained by several anatomopathological and clinical factors and the possibility of different therapeutic options, being the operative mortality among 5% and 45%. With the modern technologies it is possible to follow the evolution of the illness so to perform more appropriate therapeutic plan. From 1997 to 2007 we have observed 278 patients with acute diverticulitis. In 219 (78,7%) patients the inflammatory and sub-occlusive condition has been faced with medical therapy, with resolution of the disease in 170 (61%) cases. In 49 (17,6%) patients we have gotten the resolution of the inflammatory disease, but not of the sub-occlusion and therefore we liked to submit them to surgical treatment in election. In 1 case we have found a colovesical fistula. A total of 59 (21,2%) patients with signs of acute abdomen have been submitted to surgery in urgency, within the 24 hours from the hospitalization. We have performed a primary resection with anastomosis and without stoma in all the patients, except in 3 cases in which we have done the Hartmann procedure for the cheap general conditions. We have not recorded intra and postoperative mortality and only in 3 cases we have had a leakage, that has not needed a surgical treatment. In 9 cases we observed infection of the wound, treated with antibiotic therapy. In our experience, performing a surgical procedure, without derivative stoma and manual anastomosis, it seems to be the fittest and less expensive procedure, also in situation of emergency-urgency, without increase of mortality and morbidity.

Acetaldehyde mediates alcohol activation of the mesolimbic dopamine system

Ethanol (EtOH), the main psychoactive ingredient of alcoholic drinks, is widely considered to be responsible for alcohol abuse and alcoholism through its positive motivational properties, which depend, at least partially, on the activation of the mesolimbic dopaminergic system. However, acetaldehyde (ACD), the first metabolite of EtOH, has been classically considered to be aversive and useful in the pharmacological therapy of alcoholics. Here we show that EtOH-derived ACD is necessary for EtOH-induced place preference, a pre-clinical test with high predictive validity for reward liability. We also found that ACD is essential for EtOH-increased microdialysate dopamine (DA) levels in the rat nucleus accumbens and that this effect is mimicked by intra-ventral tegmental area (VTA) ACD administration. Furthermore, in vitro, ACD enhances VTA DA neuronal firing through action on two ionic currents: reduction of the A-type K+ current and activation of the hyperpolarization-activated inward current. EtOH-stimulating properties on DA neurons are prevented by pharmacological blockade of local catalase, the main metabolic step for biotransformation of EtOH into ACD in the central nervous system. These results provide in-vivo and in-vitro evidence for a key role of ACD in the motivational properties of EtOH and its activation of the mesolimbic DA system. Additionally, these observations suggest that ACD, by increasing VTA DA neuronal activity, would oppose its well-known peripherally originating aversive properties. Careful consideration of these findings could help in devising new effective pharmacological therapies aimed at reducing EtOH intake in alcoholics.

[Traumatic retroperitoneal haematoma]

The management of traumatic retroperitoneal haematomas is still a much debated question. Although the diagnosis has become easier using CT with contrast medium, the therapeutic decisions are still difficult because of the great variability of the lesions, which may be simple but very often complicated. Our study is based on 1086 treated patients, 29.5% of the 3682 critical abdominal polytrauma seen in 35 years. Mortality has been 12.9% with a medium ISS (Injury Severity Score) of 23.4. 71.4% of the cases were closed traumas, 28,6% were open traumas. The most common single lesions have been pelvic (43%), followed by the renal traumas (39%). Regarding the associated lesions, the thoracic traumas cause an increment of the ISS score up to 26.2% and of mortality up to 14.6%. The maxillofacial traumas associated with traumatic retroperitoneal haematomas represent 11%, mainly associated with motorcycle accidents, which have increased in the last years from 2,4% in the 70s to 32% these days. Our approach to these patients has been basically conservative. Following the indications obtained by the CT, we widely used interventional angiography, especially for renal lesions and, after pelvic stabilization, for pelvic haematomas. We have chosen surgery considering the kind of traumas (open or closed), the location of the haematoma and especially, the clinical course of the patient's hemodynamic condition.

[Total thyroidectomy: initial experience of a territorial reference center]

Authors report their initial experience in surgical treatment of thyroid diseases in an area with high percentage of thyroid tumors. Since January 2006, we examinated 428 patients. By clinical features, hormonal profile, imaging and US-guided FNAB, we selected 134 of them for surgery; 93 patients underwent thyroidectomy in January-November 2006. The Authors analyse therapeutic choises and surgical techniques, stressing the high percentage of thyroid neoplasms.

Impaired decision-making in opiate-dependent subjects: effect of pharmacological therapies

Cognitive dysfunction is a major feature of drug addiction. In the present paper, we compared the decision-making ability using the Iowa gambling task of methadone- and buprenorphine-maintained individuals to non opiate-dependent drug-free controls. Buprenorphine-maintained individuals performed better than methadone-maintained individuals, and not differently than non opiate-dependent controls. In addition, methadone-maintained individuals had more perseverative errors on the Wisconsin card sorting task (WCST) as compared with non opiate-dependent drug-free controls whereas buprenorphine-maintained individuals had intermediate scores. Scores on Weschler adult intelligence scale (WAIS-R) were similar for methadone- and buprenorphine-maintained individuals whereas drug-free controls had significantly higher scores. In addition, both opiate-dependent groups performed more poorly than drug-free controls on the Benton visual retention test (BVRT). The results suggest that buprenorphine in contrast to methadone improves decision-making, and thus may be more effective in rehabilitation programs of opiate-dependent subjects and this improvement may be related to its distinct pharmacological action as a k antagonist.

[The femoral hernia: problems in emergency surgery]

The femoral hernia can be defined as infrequent, and predominantly found in females, with the highest incidence between 30 and 40 years of age. It shows a high tendency to strangulation, also up to 40% of cases, due to the presence of the Gimbernat ligament, which with its tense fibrous margins, aids strangling known as "raised crest". The diagnosis may not be easy, overall in the clinical presence of acute abdomen in elderly patients, disabled people or people who are uncooperative during physical examination. Therefore, it should be sought with an adequate bilateral exploration of the region in all occlused patients and especially with the use of radiological images of the small intestine. The solution currently practiced is prosthetic, proposed by Lichtenstein, and variously modified by Gilbert, Rutkow, Bendavid, and other which uses a prolene plug in the shape of a cigar, umbrella, or basket, according to the size and characteristics of the parietal defect. In emergency conditions, the technique doesn?t change; but if there is stercorary contamination, it is advisable to use direct repair according to the old method of Bassini. In the last 10 years, we have treated 37 femoral hernias in emergency, using direct repair in only 2 cases. In 3 cases we used PTFE; in the other 32 cases prolene was always used; 20 patients were operated under local anesthetic, 12 under general anesthetic and 5 under peridural anesthetic. Satisfactory results were achieved, with average hospital recovery time of 1.4 days, with an early recovery between 3 and 5 days, with only 2 relapses.

Surgical management of substernal goitres. When is sternotomy inevitable?

PURPOSE

Aim of this retrospective study is to report personal experience in the surgical management of substernal goitres emphasizing the guidelines for preoperative planning of sternotomy in selected cases.

PATIENTS AND METHODS

Medical records of all patients (n=355) submitted to thyroidectomy for struma in our Operative Unit, between 1993-2003, were analysed. A substernal goitre was defined as a goitre having a significant retrosternal extension (>50%) requiring mediastinal dissection.

RESULTS

A total of 18 out of 355 patients undergoing thyroidectomy for struma in our Operative Unit had substernal goitres. The most common symptoms, at presentation, were the presence of neck mass and respiratory disorders. Standard cervical incision was adequate to achieve total thyroidectomy in 17 cases while, in one patient with computed tomography images showing the presence of a huge goitre extending below the aortic arch, a sternotomic approach was inevitable to ensure safe removal. No major morbidity or perioperative deaths occurred. One patient with scleroderma experienced bilateral paralysis of laryngeal nerves for two months, with full recovery thereafter.

CONCLUSIONS

While removal of the majority of substernal goitres can be achieved by means of cervical incision, this approach is not always safe. In a selected number of cases with an iceberg shaped substernal goiter and with >70% of the volume lying below the thoracic outlet, a sternotomic approach is inevitable. Preoperative diagnostic work-up should, thus, include chest X-ray and computed tomography. Overall results in the present patient population, have been excellent since morbidity has been minimal and mortality absent, and all patients are symptom free.

[Epidemiological survey on smoking habit among young students in Sardinia. A cross sectional study]

The study reports the prevalence of cigarette smoking among 11401 high school Sardinian students. The prevalence of smokers (40.2%) significantly differs between gender (41.1% males and 38.4% females). Males have an early initiation of smoking with an evident addictive effect by age. 54.3% are daily smokers and 21.4% smoke 15 or more cigarettes per day. More than 50% smoke to look grown-up and to be accepted by the group. Besides age (OR=1.10; 95%CI: 1.06-1.15), other factors are associated with smoke: low education level of father (OR=1.08; 95%CI: 1.02-1.15), no maternal support (OR = 1.73; 95%CI: 1.17-2.54), to have at least one smoker cohabitant (OR=1.66; 95%CI: 1.54-1.80) and alcohol drinking (OR=3.46; 95%CI: 3.04-3.93). The smokers' knowledge on smoke topics significantly differ from non smokers. Our results suggest the need of community preventive interventions, diversified for specific target populations, to modify the students' behaviours so that they respect their own health and that of their fellow citizens.

[Shall bowel obstruction caused by phytobezoar. Case report]

Bezoars are masses of indigestible material which form in the stomach. Their genesis depends on the kind of food ingested, on the presence of anomalies of the small bowel and on psychiatric disturbs. Phytobezoar rarely causes bowel obstruction and its most frequent location is the ileocecal valve. The risk increases in those patients who have undergone gastric surgery or present a reduced masticatory ability. Moreover, the genesis can be also caused by endocrine disorders.

Drug dependence as a disorder of neural plasticity: focus on dopamine and glutamate

Drug addiction, as a disease, has grown to reach the level of a social illness. Psychostimulants, opiates, alcohol, nicotine and cannabis abuse affects millions worldwide and virtually all classes of modern society. In spite of the enormous proportions of its spread, intimate neurobiological mechanisms leading to distintictive features of this pathological status, such as craving for the abused substance and loss of control over intake, remain largely obscure and pharmacotherapies sadly unsatisfactory. In the last decade, preclinical and clinical research in this field has made great progress to improve our understanding of the brain mechanisms which form the basis of this illness. The review of recent literature, which represents the focus of the present paper, leads to the emerging consensus that an alteration of physiological mechanisms of neural plasticity within the brain dopamine and glutamate systems may underlie some of the behavioral abnormalities occurring during the dependence cycle. In particular, a reduction of dopamine neuronal activity and glutamate neurotransmission at the level of the ventrotegmental area, after withdrawal from chronic administration of drugs of abuse, may work in concert with alterations in other forebrain areas, such as the nucleus accumbens and the amygdaloid complex. In addition, following prolonged periods of abstinence, even after somatic withdrawal signs have vanished, responsiveness of these systems to drugs of abuse remains abnormal. This suggests that these two neurotransmitters may play a substantial role in the long-lasting, enduring changes typical of the addictive process and may represent ideal targets for pharmacological intervention aimed at normalizing forms of neural plasticity impaired after chronic drug intake.

Clonidine fails to modify dopaminergic neuronal activity during morphine withdrawal

RATIONALE

Cellular substrates of opiate withdrawal syndrome involve several brain areas, in particular the mesolimbic dopaminergic and noradrenergic systems, but the interactions between the two pathways remain unclear.

OBJECTIVES

The aim of the present work was to investigate the effects of the alpha2-agonist clonidine on ventral tegmental area dopamine neurons during morphine withdrawal syndrome by recording their neuronal activity before and after the administration of low and relatively high doses of clonidine (from 5 to 100 microg/kg).

METHODS

The spontaneous neuronal activity of meso-accumbens dopaminergic neurons, identified by antidromical stimulation from the nucleus accumbens, was recorded by use of in vivo extracellular single-unit recordings in control and morphine-withdrawn rats after chronic administration (15 days).

RESULTS

Control rats showed a mean spontaneous firing frequency of 2.47+/-0.48 Hz, percentage of burst firing of 22+/-12 and an increase in firing after the administration of cumulative doses of clonidine (5, 10, 20, 40, 100 microg/kg). Conversely, both spontaneous firing rate (1.55+/-0.25 Hz) and the percentage of burst firing (5+/-2) were found to be significantly reduced in rats abstinent for 24 h, and increasing doses of clonidine did not re-establish electrophysiological activity observed in the controls.

CONCLUSION

The results indicate that: 1) clonidine did not restore the decreased firing activity of DA neurons in morphine-withdrawn rats, and 2) high doses of clonidine increased firing in control rats but not in morphine-withdrawn rats.

Effects of cannabinoids on prefrontal neuronal responses to ventral tegmental area stimulation

Cannabinoids activate the firing of mesoprefrontocortical dopamine neurons and release dopamine in the prefrontal cortex. This study was undertaken with the aim of clarifying the interaction between cannabinoids and mesocortical system in the prefrontal cortex. The effect of Delta9-tetrahydrocannabinol (Delta9-THC) and the synthetic CB1 agonist WIN55,212-2 (WIN) was studied by extracellular single unit recordings, in chloral hydrate anaesthetised rats, on the spontaneous activity of pyramidal neurons and on the inhibition produced on these neurons by the electrical stimulation of the ventral tegmental area (VTA). Intravenously administered Delta9-THC and WIN (1.0 and 0.5 mg/kg, respectively), increased the firing rate of pyramidal neurons projecting to the VTA. VTA stimulation produced a phasic inhibition (167 +/- 6 ms) in 79% of prefrontal cortex pyramidal neurons. Delta9-THC and WIN reverted this inhibition in 73% and 100% of the neurons tested, respectively. The subsequent administration of the selective CB1 antagonist SR141716A (1 mg/kg) readily suppressed the effects of both cannabinoids and restored the inhibitory response to VTA stimulation. Moreover, when administered alone, SR141716A prolonged the inhibition in 55.6% of the neurons tested. The results indicate that stimulation of CB1 receptors by cannabinoids results in an enhanced excitability of prefrontal cortex pyramidal neurons as indexed by the suppression of the inhibitory effect of VTA stimulation and by the increase in firing rate of antidromically identified neurons projecting to the VTA. Furthermore, our results support the view that endogenous cannabinoids exert a negative control on dopamine activity in the prefrontal cortex. This study may be relevant in helping to understand the influence of cannabinoids on cognitive processes mediated by the prefrontal cortex.

The cyclo-oxygenase inhibitor nimesulide induces conditioned place preference in rats

Two cyclo-oxygenase inhibitors, indomethacin and nimesulide, have been shown to potentiate morphine-induced stimulation of meso-accumbens dopamine neurons. In this study, an unbiased conditioned place preference procedure was used to evaluate whether nimesulide produces motivational effect after systemic administration in rats. These results show that nimesulide, at doses 0.1, 0.5 and 1 mg/kg, even lower than those usually applied for inflammatory conditions, induces conditioned place preference in rats, suggesting that it might possess rewarding properties in humans.