Multicentric validation of EndoDigest: a computer vision platform for video documentation of the critical view of safety in laparoscopic cholecystectomy.

BACKGROUND: A computer vision (CV) platform named EndoDigest was recently developed to facilitate the use of surgical videos. Specifically, EndoDigest automatically provides short video clips to effectively document the critical view of safety (CVS) in laparoscopic cholecystectomy (LC). The aim of the present study is to validate EndoDigest on a multicentric dataset of LC videos. METHODS: LC videos from 4 centers were manually annotated with the time of the cystic duct division and an assessment of CVS criteria. Incomplete recordings, bailout procedures and procedures with an intraoperative cholangiogram were excluded. EndoDigest leveraged predictions of deep learning models for workflow analysis in a rule-based inference system designed to estimate the time of the cystic duct division. Performance was assessed by computing the error in estimating the manually annotated time of the cystic duct division. To provide concise video documentation of CVS, EndoDigest extracted video clips showing the 2 min preceding and the 30 s following the predicted cystic duct division. The relevance of the documentation was evaluated by assessing CVS in automatically extracted 2.5-min-long video clips. RESULTS: 144 of the 174 LC videos from 4 centers were analyzed. EndoDigest located the time of the cystic duct division with a mean error of 124.0 ± 270.6 s despite the use of fluorescent cholangiography in 27 procedures and great variations in surgical workflows across centers. The surgical evaluation found that 108 (75.0%) of the automatically extracted short video clips documented CVS effectively. CONCLUSIONS: EndoDigest was robust enough to reliably locate the time of the cystic duct division and efficiently video document CVS despite the highly variable workflows. Training specifically on data from each center could improve results; however, this multicentric validation shows the potential for clinical translation of this surgical data science tool to efficiently document surgical safety.

A curriculum to democratize and standardize flexible endoscopy fundamental knowledge and skills: a critical review of the first 5 years of a surgical endoscopy university diploma.

BACKGROUND: As flexible endoscopy offers many advantages to patients, access to training should be aggressively encouraged. In 2014, the IRCAD-IHU-Strasbourg launched a year-long university diploma using advanced education methods to offer surgeons and gastroenterologists high-quality, personalized training in flexible endoscopy. This paper describes and critically reviews the first 5 years of the University Diploma in Surgical Endoscopy (UDSE). METHODS: The UDSE aims to progressively transmit theoretical knowledge, clinical judgment, and practical skills on basic and advanced flexible endoscopy. The 300-h year-long curriculum is composed of 100 h of online lectures with tests, 150 h of clinical rotations and 50 h of hands-on sessions. The hands-on training is delivered through validated mechanical simulators, virtual reality simulators, and specifically designed ex vivo and in vivo animal models. Participants' demographics, training, and clinical experience were recorded. Trainees' evaluations of each online lecture, hands-on training, and clinical rotations were assessed using a Likert scale from 1 (not satisfactory) to 5 (outstanding). Trainees' skill progression was evaluated using the Global Assessment of Gastrointestinal Endoscopic Skills (GAGES) proficiency test. Finally, clinical uptake was surveyed. RESULTS: 162 (79.01% males) trainees from 38 countries enrolled and successfully completed the first 5 courses. The vast majority of the trainees were surgeons and 19.14% were gastroenterologist. Sixty-nine (42.59%) participants were residents and 97 (56.79%) had no prior experience in flexible endoscopy. The online lectures, on-site sessions, and clinical rotations were highly appreciated receiving an overall average score of 4.33/5, 4.56/5, 4.43/5, respectively. Trainees' endoscopic skills improved significantly (16.68 vs. 20.53 GAGES scores; p = 0.016). At an average of 18.83 months following the course, 31 alumni (77.50% of repliers) started to use a flexible endoscope in their practice. CONCLUSIONS: Over its 5-year evolution, the UDSE has proven to be a valid means to ease access to the fundamental knowledge, practical skills, and clinical judgment necessary to achieve proficiency in surgical endoscopy.

Development and prospective validation of a scoring system for the Basic Endoscopic Skills Training (BEST) box.

AIMS: The increased use of endoscopy as a minimally invasive therapeutic technique has created a great demand for endoscopic training. The Basic Endoscopic Skills Training (BEST) box provides a low-cost solution by adapting the Fundamentals of Laparoscopic Surgery (FLS) box for flexible endoscopic simulation. The BEST box consists of six endoscopic tasks with a 5-min time limit per task. This study aims to develop a scoring system for objective evaluation of user performance. METHODS: A total of 165 participants were tested on the BEST box. Participants were divided into two groups: retrospective analysis (n = 100) and prospective analysis (n = 65). From the retrospective group, 55 individuals were also scored on the Global Assessment of Gastrointestinal Endoscopic Skills-Upper Endoscopy (GAGES-UE). Linear regression between user performance on BEST box and GAGES-UE was performed to develop the scoring system. Receiver Operating Characteristic curve was used to determine a threshold score to help users appreciate their endoscopic expertise. Prospective scoring of 65 individuals was then performed using the formula developed (20 experts and 45 trainees). RESULTS: The minimum and maximum possible scores are 30 and 110, respectively. Retrospective analysis showed that the scoring system was able to distinguish between experts and trainees (p < 0.001), correlated with GAGES-UE (p < 0.001), and had a reliability constant of r = 0.765 (p < 0.001). On prospective testing using the scoring system the expert group received a final average score of 92, whereas the average score for the trainee group was 61 (p < 0.001). CONCLUSIONS: The developed BEST box scoring system correlates with the experience level of the test taker as well as with the GAGES-UE scoring system. The results of this study add further evidence to the validity of the BEST box as an effective, low-cost endoscopic simulator with the scores used by trainees to track their performance level overtime.

Three-dimensional imaging improved the laparoscopic performance of inexperienced operators: a prospective trial.

BACKGROUND: Three-dimensional (3-D) high-definition (HD) stereovision and two-dimensional (2-D) ultra-high-resolution (4K) monitors have recently become available for laparoscopic surgery. The aim of this study was to compare laparoscopic performance between inexperienced participants using 3-D/HD and 2-D/4K monitors and those using conventional 2-D/HD monitors. METHODS: The study enrolled 66 participants with no previous surgical experience or medical training. They were randomly divided into three equal groups, each using a different type of monitor (2-D/HD, 2-D/4K, or 3-D/HD), to perform three phantom tasks using a laparoscopic simulator: Task 1, touching markers on a non-flat surface; Task 2, bimanual peg transfer; and Task 3, passing a straight rod through a loop. Each task was performed three times. The performance scores (operative time, path length of the forceps, and technical errors) were compared for each monitor type and by age group (< 30 vs. > 30 years). RESULTS: For all three tasks, scores using the 3-D monitor were significantly better than those using either 2-D monitor, with no difference between the 2-D/4K and 2-D/HD monitors. Using the 2-D monitors, the performance of Task 3 by the participants > 30 years was worse than that by the younger participants; however, there was no difference between the age groups when using the 3-D monitor. CONCLUSION: Participants with no prior experience using a 3-D monitor showed better laparoscopic performance than those using 2-D monitors, even with 4K resolution. This improvement was more marked in older participants, suggesting a greater loss of depth perception in a 2-D environment.

Hybrid fluorescent magnetic gastrojejunostomy: an experimental feasibility study in the porcine model and human cadaver.

BACKGROUND: Laparoscopic gastrojejunostomies are time consuming and require a specific training. Alternatively, sutureless anastomosis can be achieved using endoscopically delivered magnetic rings. Our aim was to assess the feasibility and reproducibility of an endo-laparoscopic gastrojejunostomy technique, using a pair of magnets coated with a near-infrared fluorescent biocompatible polymeric material. METHODS: Five pigs (3 acute and 2 survival models) and one human anatomical specimen were included. In the survival models, the distal ring was inserted into the duodenum endoscopically, and it was fixed to a thread clipped to the gastric mucosa. Twenty-four hours later, a two-port laparoscopy was performed using a near-infrared (NIR) laparoscope. The magnet position in the jejunum was detected with the transluminal fluorescence of the dye. Magnetic interaction with the metallic tip of the laparoscopic grasper allowed to capture the ring and bring the bowel loop to the future anastomotic site on the gastric wall. The proximal magnet was inserted into the stomach endoscopically and released when magnetic interaction started, allowing for a precise connection with the distal ring. The animals were followed up for 12 days and underwent control endoscopies and radiograms. In the acute animals, the anastomotic procedure was repeated 24 times. Finally, the procedure was performed in the human anatomical specimen. RESULTS: There were no technical problems, and magnetic connection could be precisely directed at both the anterior and posterior gastric walls. No complications occurred during the survival period and the anastomoses were patent on day 5. Transluminal fluorescence enabled a rapid detection of the magnet. CONCLUSIONS: Hybrid-reduced port magnetic gastrojejunostomy using a pair of fluorescently coated magnetic rings was feasible, reproducible, and easy to perform in both porcine and cadaver models.

Correction to: Discrimination between arterial and venous bowel ischemia by computer-assisted analysis of the fluorescent signal.

In the original version, Ines Gockel was omitted as a coauthor. The complete author listing is corrected here.

Discrimination between arterial and venous bowel ischemia by computer-assisted analysis of the fluorescent signal.

BACKGROUND: Arterial blood supply deficiency and venous congestion both play a role in anastomotic complications. Our aim was to evaluate a software-based analysis of the fluorescence signal to recognize the patterns of bowel ischemia. METHODS: In 18 pigs, two clips were applied on the inferior mesenteric artery (group A: n = 6) or vein (group V: n = 6) or on both (group A-V: n = 6). Three regions of interest (ROIs) were identified on the sigmoid: P = proximal to the first clip; C = central, between the two clips; and D = distal to the second clip. Indocyanine Green was injected intravenously. The fluorescence signal was captured by means of a near-infrared laparoscope. The time-to-peak (seconds) and the maximum fluorescence intensity were recorded using software. A normalized fluorescence intensity unit (NFIU: 0-to-1) was attributed, using a reference card. The NFIU's over-time variations were computed every 10 min for 50 min. Capillary lactates were measured on the sigmoid at the 3 ROIs. Various machine learning algorithms were applied for ischemia patterns recognition. RESULTS: The time-to-peak at the ischemic ROI C was significantly longer in group A versus V (20.1 ± 13 vs. 8.43 ± 3.7; p = 0.04) and in group A-V versus V (20.71 ± 11.6 vs. 8.43 ± 3.7; p = 0.03). The maximal NIFU at ROI C, was higher in the V group (1.01 ± 0.21) when compared to A (0.61 ± 0.11; p = 0.002) and A-V (0.41 ± 0.2; p = 0.0005). Capillary lactates at ROI C were lower in V (1.3 ± 0.6) than in A (1.9 ± 0.5; p = 0.0071), and A-V (2.6 ± 1.5; p = 0.034). The K nearest neighbor and the Linear SVM algorithms provided both an accuracy of 75% in discriminating between A versus V and 85% in discriminating A versus A-V. The accuracy dropped to 70% when the ML had to identify the ROI and the type of ischemia simultaneously. CONCLUSIONS: The computer-assisted dynamic analysis of the fluorescence signal enables the discrimination between different bowel ischemia models.

Adaptation of the fundamentals of laparoscopic surgery box for endoscopic simulation: performance evaluation of the first 100 participants.

BACKGROUND: The paucity of readily accessible, cost-effective models for the simulation, practice, and evaluation of endoscopic skills present an ongoing barrier for resident training. We have previously described a system for conversion of the Fundamentals of Laparoscopic Surgery box (FLS) for flexible endoscopic simulation. Six endoscopic tasks focusing on scope manipulation, and other clinically relevant endoscopic skills are performed within a 5-min time limit per task. This study describes our experience and validation results with the first 100 participants. METHODS: A total of 100 participants were evaluated on the simulator. Thirty individuals were classified as experts (having done over 200 endoscopic procedures), and 70 were classified as trainees (39 individuals reported having no prior endoscopy experience). Of the 100 participants, 55 individuals were retested on the simulator within a period of 4 months. These 55 individuals were also evaluated using the "Global Assessment of Gastrointestinal Endoscopic Skills" (GAGES). T-tests and Pearson correlations were used where appropriate, values less than 0.05 were considered significant. RESULTS: Experts completed all six tasks significantly faster than trainees. For the 55 participants who were retested on the simulator, all tasks demonstrated evidence of test-retest reliability for both experts and trainees who did not practice in between tests. Moderate correlations between lower completion times and higher GAGES scores were observed for all tasks except the clipping task. CONCLUSIONS: The results from the first 100 participants provide evidence for the simulator's validity. Based on task completion times, we found that experts perform significantly better than trainees. Additionally, preliminary data demonstrate evidence of test-retest reliability, as well as GAGES score correlation. Additional studies to determine and validate a scoring system for this simulator are ongoing.

Virtual Reality Exploration and Planning for Precision Colorectal Surgery.

BACKGROUND: Medical software can build a digital clone of the patient with 3-dimensional reconstruction of Digital Imaging and Communication in Medicine images. The virtual clone can be manipulated (rotations, zooms, etc), and the various organs can be selectively displayed or hidden to facilitate a virtual reality preoperative surgical exploration and planning. OBJECTIVE: We present preliminary cases showing the potential interest of virtual reality in colorectal surgery for both cases of diverticular disease and colonic neoplasms. DESIGN: This was a single-center feasibility study. SETTINGS: The study was conducted at a tertiary care institution. PATIENTS: Two patients underwent a laparoscopic left hemicolectomy for diverticular disease, and 1 patient underwent a laparoscopic right hemicolectomy for cancer. The 3-dimensional virtual models were obtained from preoperative CT scans. The virtual model was used to perform preoperative exploration and planning. Intraoperatively, one of the surgeons was manipulating the virtual reality model, using the touch screen of a tablet, which was interactively displayed to the surgical team. MAIN OUTCOME MEASURES: The main outcome was evaluation of the precision of virtual reality in colorectal surgery planning and exploration. RESULTS: In 1 patient undergoing laparoscopic left hemicolectomy, an abnormal origin of the left colic artery beginning as an extremely short common trunk from the inferior mesenteric artery was clearly seen in the virtual reality model. This finding was missed by the radiologist on CT scan. The precise identification of this vascular variant granted a safe and adequate surgery. In the remaining cases, the virtual reality model helped to precisely estimate the vascular anatomy, providing key landmarks for a safer dissection. LIMITATIONS: A larger sample size would be necessary to definitively assess the efficacy of virtual reality in colorectal surgery. CONCLUSIONS: Virtual reality can provide an enhanced understanding of crucial anatomical details, both preoperatively and intraoperatively, which could contribute to improve safety in colorectal surgery.

Laser ablation of the biliary tree: in vivo proof of concept as potential treatment of unresectable cholangiocarcinoma.

OBJECTIVES: The palliative treatment of cholangiocarcinoma is based on stent placement with well-known procedure-related complications. Consequently, alternative energy-based techniques were put forward with controversial long-term results. This study aims to evaluate the safety and effectiveness of biliary tree laser ablation (LA) in terms of: (i) absence of perforation, (ii) temperature increase, (iii) induced thermal damage in in vivo models. MATERIALS AND METHODS: The common bile duct and cystic ducts of two pigs were ablated with a diode laser (circumferential irradiation pattern) for 6 and 3 min at 7 W. Laser settings were chosen from previous ex vivo experiments. Local temperature was monitored through a fibre Bragg grating (FBG) sensor embedded into the laser delivery probe. Histopathological analysis of the ablated specimen was performed through in situ endomicroscopy, haematoxylin and eosin (H&E) and nicotinamide adenine dinucleotide (NADH) stains. RESULTS: Temperature reached a plateau of 53 °C with consequent thermal damage on the application area, regardless of laser settings and application sites. No perforation was detected macroscopically or microscopically. At the H&E stain, wall integrity was always preserved. The NADH stain allowed to evaluate damage extension. It turned out that the ablation spreading width depended on application time and duct diameter. In situ endomicroscopy revealed a clear distinction between ablated and non-ablated areas. CONCLUSIONS: The temperature distribution obtained through LA proved to induce a safe and effective intraductal coagulative necrosis of biliary ducts. These results represent the basis for further experiments on tumour-bearing models for the treatment of obstructive cholangiocarcinoma.

Is the advanced age a contraindication to GERD laparoscopic surgery? Results of a long term follow-up.

BACKGROUND: In this prospective non randomized observational cohort study we have evaluated the influence of age on outcome of laparoscopic total fundoplication for GERD. METHODS: Six hundred and twenty consecutive patients underwent total laparoscopic fundoplication for GERD. Five hundred and twenty-four patients were younger than 65 years (YG), and 96 patients were 65 years or older (EG). The following parameters were considered in the preoperative and postoperative evaluation: presence, duration, and severity of GERD symptoms, presence of a hiatal hernia, manometric and 24 hour pH-monitoring data, duration of operation, incidence of complications and length of hospital stay. RESULTS: Elderly patients more often had atypical symptoms of GERD and at manometric evaluation had a higher rate of impaired esophageal peristalsis in comparison with younger patients. The duration of the operation was similar between the two groups. The incidence of intraoperative and postoperative complications was low and the difference was not statistically significant between the two groups. An excellent outcome was observed in 93.0% of young patients and in 88.9% of elderly patients (p = NS). CONCLUSIONS: Laparoscopic antireflux surgery is a safe and effective treatment for GERD even in elderly patients, warranting low morbidity and mortality rates and a significant improvement of symptoms comparable to younger patients.

Innovations in surgical treatment of rectus abdominis diastasis: a review of mini-invasive techniques.

Abdominal rectus diastasis (RD) is characterized by thinning and widening of the linea alba, combined with laxity of the ventral abdominal musculature. This condition is associated with bulging of abdominal content, and it is mostly acquired during pregnancy or obesity. Symptoms include pain and discomfort in the abdomen, musculoskeletal and uro-gynecological problems in addition to negative body image and impaired quality of life. In this review we present current knowledge on the novel surgical mini-invasive techniques for treatment of RD. The aim of our study is to discuss the use of a standard classification to define pathological RD and possible indications for a minimally invasive repair, considering complications, patients' satisfaction and recurrence rate. A PubMed search of the literature has been conducted in January 2020 including the most recent articles using the following criteria among the interventions for RD: mini-invasive surgery, laparoscopic, endoscopy and robotic procedures. Minimally invasive surgical treatment options for rectus diastasis are poorly investigated and indications for repair are still debated. Guidelines are mandatory to standardize surgical management of RD.

6-Month Gastrointestinal Quality of Life (QoL) Results after Endoscopic Sleeve Gastroplasty and Laparoscopic Sleeve Gastrectomy: A Propensity Score Analysis.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) is currently the most commonly performed bariatric procedure. Endoscopic sleeve gastroplasty (ESG) is a promising new bariatric technique which is less invasive in its approach. To date no study has compared quality of life (QoL) outcomes between LSG and ESG. The aim of this study is to compare QoL after ESG and LSG using a propensity score analysis. METHODS: QoL was evaluated by means of Gastrointestinal Quality of Life Index (GIQLI) questionnaire before and 6 months after the procedure. Patients were matched for age, sex, preoperative weight, and comorbidities. RESULTS: Propensity score matching resulted in 23 pairs of patients homogeneous for age (p = 0.3), preoperative BMI (p = 0.3), sex (p = 0.74), and comorbidities (p = 0.9). Post-ESG patients, despite a less important %EWL (39.9 (17.5-58.9)vs 54.9 (46.2-65); p = 0.01) and %TWL (13.4 (7.8-20.9) vs 18.8 (17.6-21.8); p = 0.03), presented better QoL (14 [3-24] vs 13 (- 1-23) ΔGIQLI score; p = 0.79) with clear advantage for the gastrointestinal symptoms subdomain (66.5 (61-70.5) vs 59 (55-63); p = 0.001), while post-LSG patients presented a worsening of GERD symptoms (30.7% vs 0%) and an increased use of PPI therapy (p = 0.004). Resolution or improvement of comorbidities was similar (ESG 53% vs LSG 45.8%; p = 0.79) in both groups. CONCLUSION: LSG may significantly affect QoL and results in worsening of gastrointestinal symptoms including GERD. ESG is a promising less invasive bariatric endoscopic procedure that demonstrated a positive impact on both QoL and comorbidities, which could lead to greater patient acceptance earlier in their disease or at a younger age.

Endoscopic Fistula-jejunostomy for Chronic Gastro-jejunal Fistula After Sleeve Gastrectomy.

INTRODUCTION: Proximal gastric leak is one of the most common complications after laparoscopic sleeve gastrectomy (LSG). Endoscopy is the gold standard treatment for acute staple-line leaks. Surgery is the most effective treatment modality in case of chronic fistula. MATERIAL AND METHODS: A 55-year- old man presented an acute leak after LSG. The leak was treated with metal stent deployment with temporary closure. After 6 months, he presented leak recurrence with general sepsis, perigastric-infected collection, and gastro-jejunal fistula. RESULTS: Endoscopic internal drainage (EID) was performed; however, due to fistula persistence, a surgical procedure was proposed. The patient refused revisional surgery; therefore, endoscopic salvage procedure was decided. A fully covered metal stent was deployed in order to bypass the perigastric collection creating an endoscopic gastro-jejunal anastomosis. CONCLUSION: Revisional surgery is the gold standard treatment for chronic fistula after SG. Endoscopic treatment with SEMS deployment may be a sound option in selected cases especially after failure of other endoscopic techniques or refusal of revisional surgery.

Irreversible electroporation for locally advanced pancreatic cancer through a minimally invasive surgery supported by laparoscopic ultrasound.

INTRODUCTION: Pancreatic cancer is one of the most lethal cancers worldwide, with 5-years survival rate as low as 6%. The majority of pancreatic cancer patients present locally advanced or metastatic disease at diagnosis. Typically, patients affected by locally advanced pancreatic cancer (LAPC) do not undergo radical surgery but are treated with focal ablative therapies. However, a high rate of morbidity due to the heat sink effect has limited the application of ablative techniques on a routine basis in LAPC patients. Irreversible electroporation (IRE) has proved to be a new method of LAPC ablation. PRESENTATION OF THE CASE: A 69-year-old woman affected by LAPC with good response to systemic chemotherapy with FOLFIRINOX and residual 35 mm mass in the neck of the pancreas underwent to IRE through a minimally invasive surgical approach under laparoscopic ultrasound guide. The post-operative course was uneventful and the patient was discharged after 5 days. Six months after surgery she had no evidence of distant or recurrent disease. DISCUSSION: IRE has previously shown promising results in the treatment of LAPC, with relatively acceptable morbidity rates and improvement of survival. We report on the application of IRE through a minimally invasive surgical approach supported by laparoscopic ultrasound. CONCLUSION: In conclusion, we propose a novel technical approach that combines the benefits of IRE on the treatment of patients affected by LAPC with the advantages of laparoscopic surgery.

Outcome of medical and surgical therapy of GERD: predictive role of quality of life scores and instrumental evaluation.

INTRODUCTION: Aim of this study is to determine whether quality of life (QoL) assessment in association with instrumental evaluation can help to identify factors predictive of outcome both in surgically and medically treated GERD patients. METHODS: Between January 2005 and June 2010, 301 patients affected with GERD were included in the study. QoL was evaluated by means of GERD-HRQL and SF-36 questionnaires administered before treatment, at 6 months, at 1 year follow-up and at the end of the study. The multivariate analysis was used to detect if variables such as sex, age, heartburn, acid regurgitation, dysphagia, presence of esophagitis, percentage of total time at pH < 4, symptom index score (SI), the SF-36 and HRQL scores before treatment, at 6 months and 1 year could affect the QoL questionnaires scores at the end of the study. RESULTS: One hundred forty-seven patients were included in the surgical group and 154 in the medical group. No differences with regard to gender, age, mean SF-36 and HRQL scores before treatment were documented. At the end of the study, quality of life was significantly improved for SF-36 and HRQL scores, either for surgical or medical group. The multivariate analysis showed no factors individually affected the SF-36 and the HRQL scores, but symptom index score (SI) and QoL questionnaires scores at 6 months and 1 year follow-up. CONCLUSIONS: The combined use of pHmetry with evaluation of SI and QoL questionnaires can predict the outcome of GERD patients managed either by medical or surgical therapy.

Definition, incidence and etiology: what's new in the 21st century?

Actually, achalasia can be defined as a primary esophageal motor disorder characterized by esophageal aperistalsis and abnormal post-deglutitive lower esophageal sphincter (LES) relaxation. Its incidence varies from 0.03 to 1.63 cases per 100,000 people per year and increases with age, while the prevalence is almost 10/100,000 with no difference between the sexes. Regarding etiology, the most frequent histologic alteration is represented by the loss of the myenteric nerve fibers regulating inhibitory nitrergic neurotransmission in the LES, with the presence of a lymphocytic infiltrate and collagen deposition. The cause of this loss remains unclear. Among the theories proposed, the infectious, hereditary and autoimmune etiologies have been widely investigated. The only infectious agent identified as a cause of achalasia is Trypanosoma Cruzi, responsible of Chagas' disease. Regarding hereditary component, in rare cases achalasia presents as part of a genetic syndrome such as Down syndrome, Allgrove syndrome and familial visceral neuropathy. Although, no disease-specific gene has been identified. The autoimmune hypothesis has focused on the association of specific HLA classes with achalasia. However, no consistent association has been observed across studies. Despite increasing understanding of the physiopathology of achalasia, its etiology remains largely unknown. The onset of the disease is characterized by chronic inflammation of the myenteric plexus of the esophagus secondary to an environmental insult. Probably, genetic factors are involved in the development of achalasia, although the precise molecular basis of the disease has not been identified.