Long-term outcomes of Madrid approach after TAR for complex abdominal wall hernias: a single-center cohort study

PURPOSE

Undeniably, in the last 2 decades, surgical approaches in the field of abdominal wall repair have notably improved. However, the best approach to provide a durable repair with low morbidity rate has yet to be determined. The purpose of this study is to outline our long-term results following the Transverse Abdominis Release (TAR) approach in patients with complex ventral hernias, focusing on the incidence of recurrence and overall patient satisfaction following surgery.

METHODS

This is a retrospective study on 167 consecutive patients who underwent TAR between January 2015 and December 2021 for primary or recurrent complex abdominal hernias. Of these, 117 patients who underwent the open Madrid approach with the use of a double mesh (absorbable and permanent synthetic mesh) were selected and analyzed. A quality of life questionnaire (EuraHS QoL) comparing the preoperative and the postoperative status was administered.

RESULTS

Between January 2015 and December 2021, we successfully treated 117 patients presenting with complex ventral defects using the double mesh technique (absorbable and permanent synthetic mesh). Of these, 26 (22.2%) were recurrent cases. At a median follow-up period of 37.7 months, there had been 1 (0.8%) case of recurrence and 8 cases (6.8%) of bulging. The QoL score was significantly improved when compared to the preoperative status in terms of cosmesis, body perception, and physical discomfort.

CONCLUSIONS

The Madrid approach for posterior component separation is associated with both a low perioperative morbidity and recurrence rate. In accordance with other studies, we demonstrated that the TAR with reconstruction according to the Madrid approach provides excellent results in the treatment of complex abdominal wall hernias, even at long-term follow-up.

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.

Robotic transabdominal retromuscular rectus diastasis (r-TARRD) repair: a new approach

PURPOSE

The aim of this study is to present our innovative robotic approach for the treatment of rectus diastasis with concurrent primary or incisional ventral hernias.

METHODS

We performed 45 r-TARRD repairs for symptomatic rectus diastasis with concomitant associated ventral/incisional umbilical and/or epigastric hernias between January 2019 and January 2020. Data on patient demographics, type of hernia, operative time, complications, recurrence rate, and hospital stay were retrospectively analyzed. Follow-up was scheduled at 1, 6 months, and 1 year after surgery.

RESULTS

45 patients (13 M, 32 F) underwent r-TARRD repair. Mean age was 54.8 years (range 31-68) and mean BMI was 26.74 kg/m² (range 21.1-31). Mean ASA was 2.2 (range 1-3). In all patients we used a polypropylene mesh 25 × 15 cm, properly shaped. Mean operative time was 192 min (range 115-260). Mean hospital stay 4.2 days (range 2-7). No conversion to laparoscopy or open surgery and no major complications occurred. At 1-month follow-up one mesh infection (2.22%) was observed and it was treated conservatively. Four recurrences (8.88%) were reported at 1-year follow-up.

CONCLUSIONS

Robot-assisted TARRD repair is conceived as a novel alternative minimally invasive procedure for RD with concurrent midline defects ensuring a primary fascial defect closure and mesh implantation in a sublay position with a wide overlap. It is important to better evaluate the suture that should be used to perform the repair, and multicenter studies with standardization of patient's demographics, RD characteristics, and long-term follow-up outcomes are mandatory to assess the effectiveness and durability of r-TARDD repair.

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.

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.

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.

The use of biosynthetic mesh in giant hiatal hernia repair: is there a rationale? A 3-year single-center experience

PURPOSE

Reinforced prosthetic crural repair is particularly indicated for giant hiatal hernias. The rationale is to reduce the recurrence rate in the long term. The aim of our study is to evaluate the outcomes of laparoscopic giant hiatal hernia repair using a biosynthetic mesh.

METHODS

We retrospectively analyzed 44 patients who underwent laparoscopic mesh-reinforced hiatal closure and fundoplication using a biosynthetic material. Inclusion criterion was large hiatal defects (> 5 cm). Follow-up was scheduled at 6, 12 and 36 months after surgery.

RESULTS

44 patients (29F) with a mean age of 62 years (range 14-85) and mean of BMI 24.5 kg/m² (range 21-29) underwent successful laparoscopic repair. Twenty-six (59.1%) patients had Nissen-Rossetti fundoplication, whereas 18 (40.9%) had Toupet fundoplication. Six-month questionnaire for the evaluation of symptoms was available for 43 patients (97.7%) and for 40 (90.9%) patients at 12 and 36 months. Mean preoperative symptoms score analysis was 1.68 ± 0.73. Mean scores at each follow-up time were significantly improved compared to baseline (p > 0.05). Barium swallow was available in 37 patients (84.1%) at 1 year after surgery. Radiologic recurrence was observed in two patients (4.5%). No patient had symptoms attributable to recurrence or required revisional surgery. There were no mesh-related complications at 3 years follow-up.

CONCLUSIONS

The use of biosynthetic mesh for crural reinforcement is associated with a low incidence of mesh-related complications and with a reasonably low recurrence rate (4.5%) at 36 months. However, additional data with longer follow-up are needed to determine long-term safety and efficacy.

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.

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.

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.

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.

Treatment of giant paraesophageal hernia: pro laparoscopic approach

PURPOSE

Giant paraesophageal hernias (GPEH) are relatively uncommon and account for less than 5% of all primary hiatal hernias. Giant Secondary GPEH can be observed after surgery involving hiatal orifice opening, such as esophagectomy, antireflux surgery, and hiatal hernia repair. Surgical treatment is challenging, and there are still residual controversies regarding the laparoscopic approach, even though a reduced morbidity and mortality, as well as a shorter hospital stay have been demonstrated.

METHODS

A Pubmed electronic search of the literature including articles published between 1992 and 2016 was conducted using the following key words: hiatal hernia, paraesophageal hernias, mesh, laparoscopy, intrathoracic stomach, gastric volvulus, diaphragmatic hernia.

RESULTS

Given the risks of non-operative management, GPEH surgical repair is indicated in symptomatic patients. Technical steps for primary hernia repair include hernia reduction and sac excision, correct repositioning of the gastroesophageal junction, crural repair, and fundoplication. For secondary hernias, the surgical technique varies according to hernia type and components and according to the approach used during the first surgery. There is an ongoing debate regarding the best and safest method to close the hiatal orifice. The laparoscopic approach has demonstrated a lower postoperative morbidity and mortality, and a shorter hospital stay as compared to the open approach. A high recurrence rate has been reported for primary GPEH repair. However, recent studies suggest that recurrence does not reduce symptomatic outcomes.

CONCLUSIONS

The laparoscopic treatment of primary and secondary GPEH is safe and feasible in elective and emergency settings, especially in high-volume centers. The procedure is still challenging. The main steps are well defined. However, there is still room for improvement to lower the recurrence rate.

Quality assessment and cataloguing of telemedicine applications

We created a Web catalogue of approved telemedicine systems that authoritative Italian research bodies had made available for more general use. The evaluation process was divided into two stages: (1) classification of the telemedicine systems and rough preliminary evaluation; (2) assessment of the telemedicine products and services. The scoring method was applied to four well-known telemedicine systems that had been tested in health-care settings: an echocardiology teleconsulting and analysis system; a ward nursing management system; a virtual cooperative system for the management of oncology patients and a telepathology system based on remotely controlled microscopy. After technical revision during the standardization/qualification process, the applications were transferred successfully to eight new health-care facilities. The methodology achieved the main goal of providing effective tools, such as a set of quality control procedures for telemedicine and telehealth projects and a Web catalogue of telemedicine applications with a standardized level of quality, available to all interested parties.

Epiphrenic diverticula mini-invasive surgery: a challenge for expert surgeons--personal experience and review of the literature

BACKGROUND AND AIMS

While in the past, thoracotomy represented the traditional surgical approach for the treatment of epiphrenic diverticula, actually mini-invasive approach seems to be the preferred treatment as many series have been published in the recent years. This article describes the authors' experience with the laparoscopic approach for performing diverticulectomy, myotomy, and Nissen-Rossetti fundoplication.

MATERIAL AND METHODS

From 1994 to 2010, 21 patients (10 men and 11 women), mean age 58.5 years (range 45-74 years), with symptomatic epiphrenic diverticulum underwent laparoscopic diverticulectomy, myotomy and Nissen-Rossetti fundoplication.

RESULTS

The mean operative time was 135 min (range = 105-190 min). Mean hospital stay was 14.2 days (range = 7-25 days). In 5 patients (23.8%), a partial suture staple line leak was observed. Conservative treatment achieved leak resolution in all the cases. One patient (4.8%) died of a myocardial infarction in the postoperative period. After a mean clinical follow-up period of 78 months (range = 6-192 months), excellent or good outcome was referred with no dysphagia in 16 patients (80%) and only mild occasional dysphagia in 4 patients (20%).

CONCLUSIONS

Surgical treatment of epiphrenic diverticula remains a challenging procedure also by mini-invasive approach, with major morbidity and mortality rates. For this reason, indications must be restricted only to selected and symptomatic patients in specialized centers.

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.

Feasibility and effectiveness of primary umbilical hernia repair with biologic graft: preliminary study

BACKGROUND

In this prospective non-randomized observational cohort study we evaluated: the feasibility and effectiveness of primary umbilical hernia repair with open tension-free and sutureless technique using a porcine small intestinal submucosa (Surgisis) prosthesis, the quality of the treatment in terms of reduction of postoperative discomfort and the complications at early and long-term follow-up.

METHODS

Thirty-six consecutive patients, mean age 45.25 +/- 12.19 years, affected by primary umbilical uncomplicated hernia with a defect size < or = 3 cm, were treated in a day-surgery setting. A tailored flat Surgisis graft was used to ensure an overlap of at least 2 cm; in all patients the mesh was fixed by fibrin glue. Collected data included: visual analogic scale (VAS) pain scores at 24 hours, 72 hours, and 7, 15, and 30 days and number of analgesic medications after operation, complications rate, the quality of life measured by Short Form 36 health survey questionnaire (SF-36) before the operation and at long term follow-up.

RESULTS

The mean follow-up time was 5.6 +/- 1.4 years. Postoperative pain was low: the mean visual analogic scale (VAS) scores were 2.8 at 24 h, 1.8 at 72 h, and 0.9, 0.3, and 0.04 at 7, 15, and 30 days, respectively. 77.8% of the patients (28/36) did not use any analgesic drugs. Seroma was reported in 13.8% of the patients (5/36); there were no hematomas, infection, chronic pain and no major complications or mortality (< or = 30 days). Recurrence rate was 2.8% (1/36). Patient satisfaction showed a significant improvement in all SF-36 domain scores (P < 0.001).

CONCLUSIONS

The biologic mesh seems to be a safe and reliable device for repairing primary umbilical hernia with high patient comfort, even if not yet an alternative to synthetic mesh.

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.

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.

A simple test for the detection of KPC and metallo-β-lactamase carbapenemase-producing Pseudomonas aeruginosa isolates with the use of meropenem disks supplemented with aminophenylboronic acid, dipicolinic acid and cloxacillin

We evaluated the ability of the combination disk test (CDT) and the Modified Hodge Test (MHT) to discriminate between various carbapenemase-producing Pseudomonas aeruginosa isolates (KPC, n = 36; metallo-β-lactamase (MBL), n = 38) and carbapenemase non-producers (n = 75). For the CDT, the optimal inhibitor concentrations and cut-off values were: 600 μg of 3-aminophenylboronic acid (APB) per disk (an increment of ≥4 mm), 1000 μg of dipicolinic acid (DPA) per disk (an increment of ≥5 mm) and 3000 μg of cloxacillin per disk (an increment of ≥3 mm). APB had excellent sensitivity (97%) and specificity (97%) for the detection of KPC enzymes. DPA detected MBL enzymes with a sensitivity and specificity of 97% and 81%, respectively. The MHT resulted in a low sensitivity (78%) and specificity (57%). The CDT could be very useful in daily practice to provide fast and reliable detection of KPC and MBL carbapenemases among P. aeruginosa isolates.

Fluoroquinolone-resistant Streptococcus agalactiae isolates from Argentina

Fluoroquinolone resistance is a growing problem that has only recently emerged in S. agalactiae. Between 2005-2007, WHONET--Argentina network evaluated levofloxacin susceptibility in 1128 clinical S. agalactiae isolates, 10 (0.9%) of which proved to be resistant. Nine of them had come from 5 hospitals (in Buenos Aires City and 4 Argentinean provinces) and recovered from urine (n=7) and vaginal screening cultures (n=2). Three strains were also resistant to macrolides, lincosamides and B streptogramins due to the ermA gene. All nine fluoroquinolone-resistant isolates bore the same two mutations, Ser79Phe in ParC and Ser81Leu in GyrA proteins. Genetic relationships were analyzed by Apal-PFGE and two clones were determined, A (n=6) and B (n=3). To our knowledge, these are the first fluoroquinolone-resistant S. agalactiae isolates detected in Latin America.

Oxcarbazepine vs. Topiramate in Alcohol Dependence

Introduction:

Aim of this randomised, parallel, placebo-controlled group trial was to compare oxcarbazepina and topiramate with placebo on alcohol drinking indices. Craving and psychiatric simptomatology have also been investigated.

Methods:

This randomised, parallel, placebo-controlled psychopharmacology trial studied 60 patients, consecutively recruited, meeting clinical criteria for Alcohol Dependence (DSM-IV). After detoxification, subjects were assigned to flexible doses of oxcarbazepine (n=20), or topiramate (n=20) or placebo (n=20). Withdrawal symptomatology was determined by the Clinical Institute Withdrawal Assessment for Alcohol (CIWA-Ar) and the level of craving for alcohol was evaluated by a 10-cm Visual Analogue Scale (VAS) and the Italian -version of the Obsessive and Compulsive Drinking Scale (OCDS). Psychiatric symptoms were evaluated with the Symptom Check List 90 Revised (SCL-90 R).

Results:

Non-benzodiazepine anticonvulsants have been shown to be efficacious treatments for the prevention of alcohol relapse although the FDA has yet approved none of these agents. During the congress the main results of this study will be presented.

Conclusions:

To our knowledge, this is the first randomised, parallel, placebo-controlled group study to evaluate the efficacy of oxcarbazepine and topiramate compared in alcohol dependent patients. The data of this pilot clinical study suggest and investigate a possible role for the anticonvulsants agents in the treatment of alcohol dependent patients.

Mean-field annealing for phase unwrapping

Use of mean-field annealing theory is proposed for solving the phase-unwrapping (PU) problem. PU is formulated as a constrained optimization problem for the field of integer corrections to be added to the wrapped gradient field. A deterministic algorithm is described to provide an approximation of the average of the correction field over the global minima of the cost function. The proposed algorithm can be applied for any choice of the cost function. Using a cost function based on second-order differences, we obtain results close to those from simulated annealing and spend less computational time.

New regularization scheme for phase unwrapping

A new, to our knowledge, algorithm for the phase unwrapping (PU) problem that is based on stochastic relaxation is proposed and analyzed. Unlike regularization schemes previously proposed to handle this problem, our approach dispells the following two assumptions about the solution: a Gaussian model for noise and the magnitude of the true phase-field gradient's being less than pi everywhere. We formulate PU as a constrained optimization problem for the field of integer multiples of 2pi, which must be added to the wrapped phase gradient to recover the true phase gradient. By solving the optimization problem using simulated annealing with constraints, one can obtain a consistent solution under difficult conditions resulting from noise and undersampling. Results from synthetic test images are reported.

Multiwire proportional chamber system of the Fermilab single arm spectrometer

We describe a system of two groups of multiwire proportional chambers and its special purpose interface used in the Single Arm Spectrometer (SAS) facility at Fermilab. The first set measures the coordinates of the fast particle going into the spectrometer arm with a space resolution down to +/-0.5 mm. The second set, close to the target, measures the multiplicity and angular distributions of charged particles coming from the interaction. The chambers of this set have three sensitive planes with wires at 120 degrees in the same gas volume to measure three coordinates for each physical point, two readout channels per wire to minimize the inefficiency due to the very high flux and insensitive regions at the center of the chambers where they are crossed by the beam.