DEVELOPMENT OF ADENOCARCINOMA AFTER RADIOFREQUENCY ABLATION OF BARRETT'S ESOPHAGUS ASSOCIATED TO FUNDOPLICATION AND SUPPRESSION-DUODENAL DIVERSION PROCEDURE: A LESSON TO BE LEARNED

Despite endoscopic eradication therapy being an effective and durable treatment for Barrett's esophagus-related neoplasia, even after achieving initial successful eradication, these patients remain at risk of recurrence and require ongoing routine examinations. Failure of radiofrequency ablation and argon plasma coagulation is reported in 10-20% of cases.

ENDOSCOPIC ABLATION COMBINED WITH FUNDOPLICATION PLUS ACID SUPPRESSION-DUODENAL DIVERSION PROCEDURE FOR LONG SEGMENT BARRETT´S ESOPHAGUS: EARLY AND LONG-TERM OUTCOME

BACKGROUND:

The addition of endoscopic ablative therapy plus proton pump inhibitors or fundoplication is postulated for the treatment of patients with long-segment Barrett´s esophagus (LSBE); however, it does not avoid acid and bile reflux in these patients. Fundoplication with distal gastrectomy and Roux-en-Y gastrojejunostomy is proposed as an acid suppression-duodenal diversion procedure demonstrating excellent results at long-term follow-up. There are no reports on therapeutic strategy with this combination.

AIMS:

To determine the early and long-term results observed in LSBE patients with or without low-grade dysplasia who underwent the acid suppression-duodenal diversion procedure combined with endoscopic therapy.

METHODS:

Prospective study including patients with endoscopic LSBE using the Prague classification for circumferential and maximal lengths and confirmed by histological study. Patients were submitted to argon plasma coagulation (21) or radiofrequency ablation (31). After receiving treatment, they were monitored at early and late follow-up (5–12 years) with endoscopic and histologic evaluation.

RESULTS:

Few complications (ulcers or strictures) were observed after the procedure. Re-treatment was required in both groups of patients. The reduction in length of metaplastic epithelium was significantly better after radiofrequency ablation compared to argon plasma coagulation (10.95 vs 21.15 mms for circumferential length; and 30.96 vs 44.41 mms for maximal length). Intestinal metaplasia disappeared in a high percentage of patients, and histological long-term results were quite similar in both groups.

CONCLUSIONS:

Endoscopic procedures combined with fundoplication plus acid suppression with duodenal diversion technique to eliminate metaplastic epithelium of distal esophagus could be considered a good alternative option for LSBE treatment.

TOMOGRAPHIC SARCOPENIA PREDICTS ANASTOMOTIC LEAKS AND LONG-TERM SURVIVAL IN GASTRIC CANCER PATIENTS OPERATED WITH CURATIVE INTENT

BACKGROUND

The preoperative nutritional state has prognostic postoperative value. Tomographic density and area of psoas muscle are validated tools for assessing nutritional status. There are few reports assessing the utility of staging tomography in gastric cancer patients in this field.

AIMS

This study aimed to determine the influence of sarcopenia, measured by a preoperative staging computed tomography scan, on postoperative morbimortality and long-term survival in patients operated on for gastric cancer with curative intent.

METHODS

This retrospective study was conducted from 2007 to 2013. The definition of radiological sarcopenia was by measurement of cross-sectional area and density of psoas muscle at the L3 (third lumbar vertebra) level in an axial cut of an abdominopelvic computed tomography scan (in the selection without intravascular contrast media). The software used was OsirixX version 10.0.2, with the tool "propagate segmentation", and all muscle seen in the image was manually adjusted.

RESULTS

We included 70 patients, 77% men, with a mean cross-sectional in L3 of 16.6 cm2 (standard deviation+6.1) and mean density of psoas muscle in L3 of 36.1 mean muscle density (standard deviation+7.1). Advanced cancers were 86, 28.6% had signet-ring cells, 78.6% required a total gastrectomy, postoperative surgical morbidity and mortality were 22.8 and 2.8%, respectively, and overall 5-year long-term survival was 57.1%. In the multivariate analysis, cross-sectional area failed to predict surgical morbidity (p=0.4) and 5-year long-term survival (p=0.34), while density of psoas muscle was able to predict anastomotic fistulas (p=0.009; OR 0.86; 95%CI 0.76-0.96) and 5-year long-term survival (p=0.04; OR 2.9; 95%CI 1.04-8.15).

CONCLUSIONS

Tomographic diagnosis of sarcopenia from density of psoas muscle can predict anastomotic fistulas and long-term survival in gastric cancer patients treated with curative intent.

Observational medical treatment or surgery for giant paraesophageal hiatal hernia in elderly patients

Giant paraesophageal hernias (GPHH) occur frequently in the elderly and account for about 5-10% of all hiatal hernias. Up to now controversy persists between expected medical treatment and surgical treatment. To assess if an indication for surgical repair of GPHH is possible in elderly patients. A prospective study that includes patients over 70 years of age hospitalized from January 2015 to December 2019 with GPHH. Patients were separated into Group A and Group B. Group A consisted of a cohort of 23 patients in whom observation and medical treatment were performed. Group B consisted of 44 patients submitted to elective laparoscopic hiatal hernia repair. Symptomatic patients were observed in both groups (20/23 in Group A and 38/44 in Group B). Charlson's score >6 and ASA II or III were more frequent in Group A. Patients in Group A presented symptoms many years before their hospitalization in comparison to Group B (21.8+7.8 vs. 6.2+3.5 years, respectively) (P=0.0001). Emergency hospitalization was observed exclusively in Group A. Acute complications were frequently observed and hospital stays were significantly longer in Group A, 14 patients were subjected to medical management and 6 to emergency surgery. In-hospital mortality occurred in 13/20 patients (65%) versus 1/38 patients (2.6%) in Group B (P=0.0001). Laparoscopic paraesophageal hiatal hernia repair can be done safely, effectively, and in a timely manner in elderly patients at specialized surgical teams. Advanced age alone should not be a limiting factor for the repair of paraesophageal hernias.

LAPAROSCOPIC REDO FUNDOPLICATION ALONE, REDO NISSEN FUNDOPLICATION, OR TOUPET FUNDOPLICATION COMBINED WITH ROUX-EN-Y DISTAL GASTRECTOMY FOR TREATMENT OF FAILED NISSEN FUNDOPLICATION

BACKGROUND:

Laparoscopic Nissen fundoplication fails to control the gastroesophageal reflux in almost 15% of patients, and most of them must be reoperated due to postoperative symptoms. Different surgical options have been suggested.

AIMS:

This study aimed to present the postoperative outcomes of patients submitted to three different procedures: redo laparoscopic Nissen fundoplication alone (Group A), redo laparoscopic Nissen fundoplication combined with distal gastrectomy (Group B), or conversion to laparoscopic Toupet combined with distal gastrectomy with Roux-en-Y gastrojejunostomy (Group C).

METHODS:

This is a prospective study involving 77 patients who were submitted initially to laparoscopic Nissen fundoplication and presented recurrence of gastroesophageal reflux after the operation. They were evaluated before and after the reoperation with clinical questionnaire and objective functional studies. After reestablishing the anatomy of the esophagogastric junction, a surgery was performed. None of the patients were lost during follow-up.

RESULTS:

Persistent symptoms were observed more frequently in Group A or B patients, including wrap stricture, intrathoracic wrap, or twisted fundoplication. In Group C, recurrent symptoms associated with this anatomic alteration were infrequently observed. Incompetent lower esophageal sphincter was confirmed in 57.7% of patients included in Group A, compared to 17.2% after Nissen and distal gastrectomy and 26% after Toupet procedure plus distal gastrectomy. In Group C, despite the high percentage of patients with incompetent lower esophageal sphincter, 8.7% had abnormal acid reflux after surgery.

CONCLUSIONS:

Nissen and Toupet procedures combined with Roux-en-Y distal gastrectomy are safe and effective for the management of failed Nissen fundoplication. However, Toupet technique is preferable for patients suffering from mainly dysphagia and pain.

WHEN SHOULD BE CONVERTED LAPAROSCOPIC SLEEVE GASTRECTOMY TO LAPAROSCOPIC ROUX-EN-Y GASTRIC BYPASS DUE TO GASTROESOPHAGEAL REFLUX?

Background:

Gastroesophageal reflux (GER) is one of the most common indications for conversion of sleeve gastrectomy (LSG) to laparoscopic Roux-en-Y gastric bypass (LRYGBP). Objective evaluations are necessary in order to choose the best definitive treatment for these patients.

Aim:

To present and describe the findings of the objective studies for gastroesophageal reflux disease performed before LSG conversion to LRYGBP in order to support the indication for surgery.

Method:

Thirty-nine non-responder patients to proton pump inhibitors treatment after LSG were included in this prospective study. They did not present GER symptoms, esophagitis or hiatal hernia before LSG. Endoscopy, radiology, manometry, 24 h pH monitoring were performed.

Results:

The mean time of appearance of reflux symptoms was 26.8+24.08 months (8-71). Erosive esophagitis was found in 33/39 symptomatic patients (84.6%) and Barrett´s esophagus in five. (12.8%). Manometry and acid reflux test were performed in 38/39 patients. Defective lower esophageal sphincter function was observed independent the grade of esophagitis or Barrett´s esophagus. Pathologic acid reflux with elevated DeMeester´s scores and % of time pH<4 was detected in all these patients. more significant in those with severe esophagitis and Barrett´s esophagus. Radiologic sleeve abnormalities were observed in 35 patients, mainly cardia dilatation (n=18) and hiatal hernia (n=11). Middle gastric stricture was observed in only six patients.

Conclusion:

Patients with reflux symptoms and esophagitis or Barrett´s esophagus after SG present defective lower esophageal sphincter function and increased acid reflux. These conditions support the indication of conversion to LRYGBP.

LYMPHOPARIETAL INDEX IN ESOPHAGEAL CANCER IS STRONGER THAN TNM STAGING IN LONG-TERM SURVIVAL PROGNOSIS IN A LATIN-AMERICAN COUNTRY

BACKGROUND

The identification of prognostic factors of esophageal cancer has allowed to predict the evolution of patients.

AIM

Assess different prognostic factors of long-term survival of esophageal cancer and evaluate a new prognostic factor of long-term survival called lymphoparietal index (N+/T).

METHOD

Prospective study of the Universidad de Chile Clinical Hospital, between January 2004 and December 2013. Included all esophageal cancer surgeries with curative intent and cervical anastomosis. Exclusion criteria included: stage 4 cancers, R1 resections, palliative procedures and emergency surgeries.

RESULTS

Fifty-eight patients were included, 62.1% were men, the average age was 63.3 years. A total of 48.3% were squamous, 88% were advanced cancers, the average lymph node harvest was 17.1. Post-operative surgical morbidity was 75%, with a 17.2% of reoperations and 3.4% of mortality. The average overall survival was 41.3 months, the 3-year survival was 31%. Multivariate analysis of the prognostic factors showed that significant variables were anterior mediastinal ascent (p=0.01, OR: 6.7 [1.43-31.6]), anastomotic fistula (p=0.03, OR: 0.21 [0.05-0.87]), N classification (p=0.02, OR: 3.8 [1.16-12.73]), TNM stage (p=0.04, OR: 2.8 [1.01-9.26]), and lymphoparietal index (p=0.04, RR: 3.9 [1.01-15.17]. The ROC curves of lymphoparietal index, N classification and TNM stage have areas under the curve of 0.71, 0.63 and 0.64 respectively, with significant statistical difference (p=0.01).

CONCLUSION

The independent prognostic factors of long-term survival in esophageal cancer are anterior mediastinal ascent, anastomotic fistula, N classification, TNM stage and lymphoparietal index. In esophageal cancer the new lymphoparietal index is stronger than TNM stage in long-term survival prognosis.

LESSONS LEARNED ANALYZING COMPLICATIONS AFTER LAPAROSCOPIC TOTAL GASTRECTOMY FOR GASTRIC CANCER

Background:

Laparoscopic surgery has been gradually accepted as an option for the surgical treatment ofgastric cancer. There are still points that are controversial or situations that are eventually associated with intra-operative difficulties or postoperative complications.

Aim:

To establish the relationship between the difficulties during the execution of total gastrectomy and the occurrence of eventual postoperative complications.

Method:

The operative protocols and postoperative evolution of 74 patients operated for gastriccancer, who were subjected to laparoscopic total gastrectomy (inclusion criteria) were reviewed. The intraoperative difficulties recorded in the operative protocol and postoperative complications of a surgical nature wereanalyzed (inclusion criteria). Postoperative medical complications were excluded (exclusion criteria). For the discussion, an extensive bibliographical review was carried out.

Results:

Intra-operative difficulties or complications reported correspond to 33/74 and of these; 18 events (54.5%) were related to postoperative complications and six were absolutely unexpected. The more frequent were leaks of the anastomosis and leaks of the duodenal stump; however, other rare complications were observed. Seven were managed with conservative measures and 17 (22.9%) required surgical re-exploration, with a postoperative mortality of two patients (2.7%).

Conclusion:

We have learned that there are infrequent and unexpected complications; the treating team must be mindful of and, in front of suspicion of complications, anappropriate decision must be done which includes early re-exploration. Finally, after the experience reported, some complications should be avoided.

Hiatal hernia repair: prevention of mesh erosion and migration into the esophagogastric junction

Background:

Erosion and migration into the esophagogastric lumen after laparoscopic hiatal hernia repair with mesh placement has been published.

Aim:

To present surgical maneuvers that seek to diminish the risk of this complication.

Method:

We suggest mobilizing the hernia sac from the mediastinum and taking it down to the abdominal position with its blood supply intact in order to rotate it behind and around the abdominal esophagus. The purpose is to cover the on-lay mesh placed in “U” fashion to reinforce the crus suture.

Results:

We have performed laparoscopic hiatal hernia repair in 173 patients (total group). Early postoperative complications were observed in 35 patients (27.1%) and one patient died (0.7%) due to a massive lung thromboembolism. One hundred twenty-nine patients were followed-up for a mean of 41+28months. Mesh placement was performed in 79 of these patients. The remnant sac was rotated behind the esophagus in order to cover the mesh surface. In this group, late complications were observed in five patients (2.9%). We have not observed mesh erosion or migration to the esophagogastric lumen.

Conclusion:

The proposed technique should be useful for preventing erosion and migration into the esophagus.

INTRODUCTION OF THE NEW LYMPHOPARIETAL INDEX FOR GASTRIC CANCER PATIENTS

Background:

The identification of prognostic factors of gastric cancer (GC) has allowed to predict the evolution of patients.

Aim:

Assess the reliability of the lymphoparietal index in the prediction of long-term survival in GC treated with curative intent.

Method:

Prospective study of the Universidad de Chile Clinical Hospital, between May 2004 and May 2012. Included all gastric cancer surgeries with curative intent. Exclusion criteria were: gastrectomies due to benign lesions, stage 4 cancers, R1 resections, palliative procedures, complete esophagogastrectomies and emergency surgeries.

Results:

A total of 284 patients were included; of the sample 65.4% were male,mean age of 64.5 years,75% were advanced cancers, 72.5% required a total gastrectomy, 30 lymph nodes harvest. Surgical morbidity and mortality were 17.2% and 1.7%. 5-year survival was 56.9%. The N+/T index could predict long-term survival in all de subgrups (p<0.0001), although had a reliable prediction in early GC (p=0.005), advanced GC (p<0.0001), signet ring cell GC (p<0.0001), proximal GC (p<0.0001) and distal GC (p<0.0001). The ROC curves N+/T index, LNR and T classification presented areas below the curve of 0.789, 0.786 and 0,790 respectively, without a significant statistical difference (p=0.96).

Conclusion:

The N+/T index is a reliable quotient in the prognostic evaluation of gastric adenocarcinoma patients who have been resected with curative intent.

FAILURE AFTER FUNDOPLICATION: RE-FUNDOPLICATION? IS THERE A ROOM FOR GASTRECTOMY? IN WHICH CLINICAL SCENARIES?

Background:

Re-fundoplication is the most often procedure performed after failed fundoplication, but re-failure is even higher.

Aim:

The objectives are: a) to discuss the results of fundoplication and re-fundoplication in these cases, and b) to analyze in which clinical situation there is a room for gastrectomy after failed fundoplication.

Method:

This experience includes 104 patients submitted to re-fundoplication after failure of the initial operation, 50 cases of long segment Barrett´s esophagus and 60 patients with morbid obesity, comparing the postoperative outcome in terms of clinical, endoscopic, manometric and 24h pH monitoring results.

Results:

In patients with failure after initial fundoplication, redo-fundoplication shows the worst clinical results (symptoms, endoscopic esophagitis, manometry and 24 h pH monitoring). In patients with long segment Barrett´s esophagus, better results were observed after fundoplication plus Roux-en-Y distal gastrectomy and in obese patients similar results regarding symptoms, endoscopic esophagitis and 24h pH monitoring were observed after both fundoplication plus distal gastrectomy or laparoscopic resectional gastric bypass, while regarding manometry, normal LES pressure was observed only after fundoplication plus distal gastrectomy.

Conclusion:

Distal gastrectomy is recommended for patients with failure after initial fundoplication, patients with long segment Barrett´s esophagus and obese patients with gastroesophageal reflux disease and Barrett´s esophagus. Despite its higher morbidity, this procedure represents an important addition to the surgical armamentarium.

Late esophagogastric anatomic and functional changes after sleeve gastrectomy and its clinical consequences with regards to gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is described as a complication after sleeve gastrectomy. Most studies have used only clinical symptoms or upper gastrointestinal endoscopy for evaluation of reflux after surgery. Manometry, acid reflux tests, and esophageal barium swallow have not been commonly used. The objective of this study is to evaluate the short- and long-term incidence of clinical gastroesophageal reflux, the lower esophageal sphincter (LES) pressure, acid reflux, and endoscopic and radiological changes after sleeve gastrectomy (SG). A total of 315 patients were studied after SG; 248 (78.3%) completed more than 5 years of follow-up and 67 (21.4%) have more than 8 years (range 8-10 years) of follow-up. The preoperative weight was 106 + 14.1 kg with a mean body mass index 38.4 + 3.4 kg/m2. Patients with prior GERD were excluded for SG. During the follow-up patients were subjected to clinical, endoscopic, radiological, manometric, and 24-hour pH monitoring and duodenogastric reflux evaluations. Reflux symptoms were observed in 65.1% of patients at late follow-up. Patients without reflux symptoms presented an LES resting pressure of 13.3 ± 4.2 mmHg while patients with reflux symptoms presented an LES resting pressure of 9.8 + 2.1 mmHg. In patients with reflux symptoms, a positive acid reflux test was observed in 77.5% of patients with a mean DeMeester score of 41.7 ± 2.9 (range 14.1-131.7). During endoscopy, esophagitis was found in 29.4%, hiatal hernia in 5.7%, and Barrett's esophagus was diagnosed in 4.8%. Positive duodenogastric reflux was found in 31.8% of patients and 57.7% of our patients received proton pump inhibitor treatment after SG. Sleeve gastrectomy presents anatomic and functional changes that are associated with increased GERD.

Duodenogastric biliary reflux assessed by scintigraphic scan in patients with reflux symptoms after sleeve gastrectomy: preliminary results

BACKGROUND

Bile reflux is a factor in the appearance of severe esophagitis and Barrett's esophagus, which have been reported after sleeve gastrectomy (SG). Incompetent lower esophageal sphincter and increased gastroesophageal acid reflux have been demonstrated after this operation. Some reports have shown bile content in the antrum during endoscopic control, but no investigations objectively confirm the presence of duodenogastric bile reflux in these patients.

OBJECTIVES

To evaluate the presence of duodenogastric bile reflux (DGR) after SG in patients presenting reflux symptoms.

SETTING

University hospital.

METHODS

Prospective study of 22 patients presenting reflux symptoms who underwent SG for morbid obesity and who received endoscopic evaluation and scintigraphic study to confirm esophagitis and duodenogastric bile reflux.

RESULTS

Erosive esophagitis was observed in 11 patients and Barrett's esophagus in 2 patients. Seven patients (31.8%) presented positive DGR. Among them, 3 had type B and C esophagitis. The other 4 patients did not present esophagitis in spite of reflux symptoms.

CONCLUSION

DGR may be present in patients with gastroesophageal reflux after SG. This line of investigation requires further studies to confirm this hypothesis.

PHARYNGO-ILEO-COLO-ANASTOMOSIS WITH MICRO-VASCULAR BLOOD SUPPLY AUGMENTATION FOR ESOPHAGO-GASTRIC REPLACEMENT DUE TO ESOPHAGO-GASTRIC NECROSIS AFTER CAUSTIC INGESTION

BACKGROUND

Complete esophago-gastric necrosis after caustic ingestion is a challenging surgical scenario for reconstruction of the upper digestive transit.

AIM

To present a surgical technique for reconstruction of the upper digestive tract after total esophagectomy and gastrectomy due to esophageal and gastric necrosis.

METHOD

The transit was re-established by means of a pharyngo-ileo-colic interposition with microsurgical arterial and venous anastomosis for augmentation of blood supply. Colo-duodeno-anastomosis and ileo-transverse colic anastomosis were performed for complete digestive transit reconstruction.

RESULT

This procedure was applied in a case of 41 years male attempted suicide by ingesting alkali caustic liquid (concentrated sodium hydroxide). Total necrosis of the esophagus and stomach occurred, which required initially total esophago-gastrectomy, closure at the level of the crico-pharyngeal sphincter and jejunostomy for enteral feeding with a highly deteriorated quality of life . The procedure was performed later and there were no major early and late postoperative complications and normal nutritional conditions were re-stablished.

CONCLUSION

The procedure is feasible and must be managed by multidisciplinary team in order to re-establish a normal quality of life.

Laparoscopic subtotal gastrectomy in morbid obese patients: a valid option to laparoscopic gastric bypass in particular circumstances (prospective study)

BACKGROUND

Laparoscopic Roux-en-Y Gastric Bypass (LRYGB) without resection of the distal stomach is largely performed over the world for morbid obesity. Potential risk of gastric remnant carcinoma development has been suggested.

PURPOSE

To present the results obtained after LRYGB with resection of distal stomach.

METHOD

This prospective study includes 400 consecutive patients. The mean body weight was 105.9 ± 16.8 Kg (range 83-145 kg), and body mass index (BMI) was 38.5 ± 4.4 kg/m² (32.9-50.3). Postoperative morbid-mortality and follow-up were analyzed.

RESULTS

Operative time was 128.5 ± 18.7 min, hospital discharge occurred at 3rd postoperative day, postoperative complications occurred in 9.25%, early surgical complications were observed in 3% and medical complications 4%, late surgical complications occurred 2.25%, no mortality was observed. At 1 year follow-up, BMI was 25.3 ± 2.7 kg/m² with % of weight loss (%WL) of 84.6 + 19.1%. At five years follow-up very similar values were observed.

CONCLUSION

The results obtained after LRYGB with resection of distal stomach are similar to results published after non resection LRYGB regarding early and late results and can be indicated in high risk areas of gastric carcinoma.

Patients Having Bariatric Surgery: Surgical Options in Morbidly Obese Patients with Barrett's Esophagus

This article summarizes the currently knowledge and results observed in patients with obesity and Barrett's esophagus which were presented and discussed during the IFSO 2014 held in Montreal. In this meeting, the surgical options for the management after bariatric surgery were discussed. For this purpose, a complete revision of the available literature was done including Pubmed, Medline, Scielo database, own experience, and experts opinion. A total of 49 publications were reviewed and included in the present paper. The majority of authors agree that gastric bypass is the procedure of choice. Sleeve gastrectomy is not an absolute contraindication. Up to now, gastric bypass appears to be the best procedure for treatment of obese patients with Barrett's esophagus. Future investigations should give the definitive consensus.

Esophagocardioplasty, vagotomy-antrectomy and Roux-en-Y gastrojejunostomy: indication in cases with severe esophageal motor disfunction

Almost 10% of patients with Crest syndrome associated with severe gastroesophageal reflux and 5-10% of patients with failed cardiomyotomy for achalasia present with cardial or distal esophageal organic stricture. Some of these cases are poor risk patients for surgery and therefore the surgeon must offer a safe procedure with low morbimortality, keeping in mind the pathophysiological motor pattern of these patients.In order to treat the stricture to improve the esophageal transit we treated patients with esophagocardioplasty associated with vagotomy-antrectomy and Roux-en-Y gastrojejunostomy, thereby avoiding the potential acid or biliary reflux in poor risk patients in whom esophagectomy would be a very deleterious procedure. All four patients had a good postoperative evolution and late control demonstrated good esophagogastric transit with no postoperative esophagitis.

SINGLE ANASTOMOSIS GASTRIC BYPASS (ONE ANASTOMOSIS GASTRIC BYPASS OR MINI GASTRIC BYPASS): THE EXPERIENCE WITH BILLROTH II MUST BE CONSIDERED AND IS A CHALLENGE FOR THE NEXT YEARS

INTRODUCTION

Single anastomosis gastric bypass (one anastomosis gastric bypass or mini-gastric bypass) has been presented as an option of surgical treatment for obese patients in order to reduce operation time and avoiding eventual postoperative complications after Roux-en-Y gastric bypass.The main late complication could be related to bile reflux.

AIM

To report the experiences published after Billroth II anastomosis and its adverse effects regarding symptoms and damage on the gastric and esophageal mucosa .

METHOD

For data recollection Medline, Pubmed, Scielo and Cochrane database were accessed, giving a total of 168 papers being chosen 57 of them.

RESULTS

According the reported results during open era surgery for peptic disease and more recent results for gastric cancer surgery, bile reflux and its consequences are more frequent after Billroth II operation compared to Roux-en-Y gastrojejunal anastomosis.

CONCLUSION

These findings must be considered for the indication of bariatric surgery.

SLEEVE GASTRECTOMY AND FUNDOPLICATION AS A SINGLE PROCEDURE IN PATIENTS WITH OBESITY AND GASTROESOPHAGEAL REFLUX

BACKGROUND

Bariatric surgery in Chile has seen an exponential increase in recent years, especially in sleeve gastrectomy. Its use is currently discussed in patients suffering from gastroesophageal reflux disease. Different options have been considered for the management of these patients but up to now laparoscopic Roux-en-Y gastric bypass seems to be the best option. Sleeve gastrectomy plus concomitant fundoplication or hiatal hernia repair also has been suggested in patients having reflux or small hiatal hernia.

AIM

To present a cohort of obese patients with gatroesophageal reflux undergoing this procedure, which seeks to provide the benefits of both laparoscopic gastric sleeve (LSG) and antireflux surgery focused on the evaluation of presence of reflux and BMI after surgery, and to compare the result observed in this cohort with a previous group of obese patients without reflux submitted to sleeve gastrectomy alone.

METHODS

Retrospective case series in 15 patients who underwent this surgery between the years 2003 and 2012. Clinical records were analyzed and values ​​of 24 hr pH monitoring, esophageal manometry and clinical outcome were recorded. Results were compared to a previous series of patients who underwent LSG. No statistical analyses were made.

RESULTS

Group A consisted of 15 patients submitted to LSG plus fundoplication. 93% (n=14) were female. Mean age was 46.2 years. Mean preoperative body mass index (BMI) was 33.9. All patients had altered pH monitoring and manometry preoperatively. There was one minor complication corresponding to a seroma. There was no perioperative mortality. Group B consisted of 23 obese patients who underwent LSG. These patients developed de novo reflux, hypotensive LES and esophagitis after the surgery. Group A patients showed improvement in esophageal pH monitoring and manometry at three months. During long-term follow-up, six underwent revision surgery, four for weight regain, one regained weight associated with symptomatic reflux, and one underwent re-intervention for reflux.

CONCLUSIONS

Good results are observed in the short-term follow up in both reflux resolution and weight loss. Nevertheless, results at long term are discouraging, with 53.3% of the patients requiring revision surgery during follow-up.

Gastroesophageal Reflux Disease and Sleeve Gastrectomy

Gastroesophageal reflux disease (GERD) and/or hiatus hernia (HH) are one of the most common disorders of the upper gastrointestinal tract. Despite the positive effect of sleeve gastrectomy (SG) regarding weight loss and improvement in obesity co-morbidities, there are concerns about the development of de novo gastroesophageal reflux disease or worsening the existing GERD after this bariatric operation. Furthermore, controversy exists on the consequences of SG in lower esophageal sphincter function and about the ideal procedure when a hiatus hernia is preoperatively diagnosed or discovered during the laparoscopic SG. This review systematically investigates the incidence, the pathophysiology of GERD and/or HH in morbidly obese individuals before and after SG, and the treatment options for concomitant HH repair during laparoscopic sleeve gastrectomy.

[Esophageal sarcomatoid squamous carcinoma: report of one case]

Sarcomatoid squamous carcinoma (ESC) is a rare esophageal neoplasm, with a clinical, etiological and pathological behavior that differs from squamous cancer. From the histological point of view it has a dual configuration. The squamous epithelial component is usually limited to small areas, while the major part is constituted by mesenchymatous (sarcomatoid) polypoid tissue. Treatment is esophagectomy or total esophagogastrectomy depending on the tumor location. Early detection is critical in terms of survival. For large lesions, preoperative chemo-radiotherapy can be considered. We report a 78-year-old male presenting with dysphagia. An upper gastrointestinal endoscopy showed a tumor located below the cardia. The patient was subjected to a total esophageal and gastric resection. In a second operation, the digestive transit was reconstituted in 2 steps. The pathology report informed a sarcomatoid squamous carcinoma. After 18 months of follow up, the patient is ambulatory.

Gastric stenosis after laparoscopic sleeve gastrectomy in morbidly obese patients

Laparoscopic sleeve gastrectomy (LSG) is an effective bariatric procedure. The objective of this study is to describe a series of patients who were subjected to LSG and then developed gastric stenosis, with an emphasis on their treatment and a discussion of the possible underlying mechanisms. From January 2006 to October 2012, 717 patients with morbid obesity underwent LSG in our institution. Out of 717 patients, 571 (79.6 %) were women. The mean age was 36.9 years with a BMI of 37.3 kg/m(2). Five patients (0.69 %) developed gastric stenosis. Treatment of the stenosis was endoscopic dilatations; however, one patient required a conversion to laparoscopic Roux-en-Y gastric bypass. Stenosis after LSG is rare but requires early diagnosis and treatment.

Outcomes of esophageal surgery, especially of the lower esophageal sphincter

This paper includes commentaries on outcomes of esophageal surgery, including the mechanisms by which fundoduplication improves lower esophageal sphincter (LES) pressure; the efficacy of the Linx™ management system in improving LES function; the utility of radiologic characterization of antireflux valves following surgery; the correlation between endoscopic findings and reported symptoms following antireflux surgery; the links between laparoscopic sleeve gastrectomy and decreased LES pressure, endoscopic esophagitis, and gastroesophageal reflux disease (GERD); the less favorable outcomes following fundoduplication among obese patients; the application of bioprosthetic meshes to reinforce hiatal repair and decrease the incidence of paraesophageal hernia; the efficacy of endoluminal antireflux procedures, and the limited efficacy of revisional antireflux operations, underscoring the importance of good primary surgery and diligent work-up to prevent the necessity of revisional procedures.

Type 2 diabetes mellitus in patients with mild obesity: preliminary results of surgical treatment

In the last years, type 2 diabetes mellitus (T2DM) and obesity have become a serious public health problem, behaving as epidemic diseases. There is great interest in exploring different options for the treatment of T2DM in nonmorbidly obese patients. The purpose of this study is to report parameters of glycemic control in patients with T2DM and mild obesity who underwent laparoscopic Roux-en-Y gastric bypass (RYGBP). This prospective clinical trial includes patients with T2DM with a body mass index (BMI) between 30 and 35 kg/m(2) who underwent laparoscopic RYGBP from July 2008 through October 2010. Thirty-one patients were included in the study, 15 men and 16 women, with an average age of 48.7 ± 8.6 years. The average time since onset of T2DM was 5.8 years. The average postoperative follow-up was 30.4 months. The average preoperative blood glucose and glycosylated hemoglobin were 152 ± 70 mg/dl and 7.7 ± 2.1 %, respectively. All of them were using oral hypoglycemic agents, and four patients were insulin dependent. Only one patient had a postoperative complication (hemoperitoneum). At 36 months follow-up, the average BMI decreased to 24.7 kg/m(2), all patients (31) showed improvement in their glycemic control, and 29 of them (93.6 %) met the criteria for remission of T2DM in the last control. Laparoscopic RYGBP is a safe and effective procedure that improves glycemic control in patients with T2DM and mild obesity at midterm follow-up.

[Hiatal hernias: why and how should they be surgically treated]

INTRODUCTION

There is controversy in the literature about the choice of expectant medical treatment versus surgical treatment of hiatal hernias, depending on the presence or absence of symptoms. This study presents the results obtained by our group, considering disease duration and postoperative results.

PATIENTS AND METHOD

A total of 121 patients were included and divided by age, disease duration, type of hiatal hernia and postoperative outcome.

RESULTS

In 32% of the patients younger than 70 years, symptom duration was longer than 11 years and 68% of those aged more than 71 years had long-term symptoms (p<.05). Type iv hernias (complex) and those with diameters measuring more than 16 cm were observed in the group with longer symptom duration. Complications were more frequent in the older age group, in those with longer symptom duration and in those with type iv complex hernias. There was no postoperative mortality and only one patient (0.8%) with a type iii hernia and severe oesophagitis required reoperation.

CONCLUSION

We recommend that patients with hiatal hernia undergo surgery at diagnosis to avoid complications and risks. Older patients should not be excluded from surgical indication but should undergo a complete multidisciplinary evaluation to avoid complications and postoperative mortality.

Reconstituição do trato digestivo após falha de esofagogastro ou esofagocolo anastomose

RACIONAL: Disfagia grave ou mesmo afagia pode ocorrer após esofagectomia secundária à necrose do órgão ascendido com estenose severa ou separação completa dos cotos. Ruptura catastrófica esofágica ou gástrica impulsiona a decisão de "desconectar" o esôfago, a fim de evitar graves complicações sépticas. As operações utilizadas para restabelecer a descontinuidade do esôfago não são padronizadas e reoperações para restabelecimento do trânsito digestivo superior são um verdadeiro desafio. MÉTODOS: Este é estudo retrospectivo da experiência dos autores durante 17 anos incluindo 18 pacientes, 14 previamente submetidos à esofagectomia e quatro esofagogastrectomia. Eles foram operados com o fim de restabelecer o trato digestivo superior. RESULTADOS: Refazer esofagogastro anastomose foi possível em 12 pacientes, 10 por meio da abordagem cervical e combinando esternotomia em quatro, a fim de realizar a nova anastomose. Em cinco pacientes esofagocolo anastomose foi novamente realizada. Interposição de enxerto livre de jejuno foi realizada em um paciente. As complicações ocorreram em 10 pacientes (55,5%): deiscência anastomótica em três, estenose em quatro, condrite esternal em dois e abscesso cervical em um. Não se observou mortalidade. CONCLUSÃO: Existem diferentes opções cirúrgicas para o tratamento desta situação clínica difícil e arriscada; deve ser tratada com procedimentos adaptados de acordo com o segmento anatômico disponível para ser usado, escolhendo o procedimento mais conservador.

Barrett's esophagus: surgical treatments

The following on surgical treatments for Barrett's esophagus includes commentaries on the indications for antireflux surgery after medical treatment; the effects of the various procedures on the lower esophageal sphincter; the role of impaired esophageal motility and delayed gastric emptying in the choice of the surgical procedure; indications for associated highly selective vagotomy, duodenal switch, and gastric electrical stimulation; therapeutic strategies for detection and treatment of shortened esophagus; the role of antireflux surgery on the regression of metaplastic mucosa and the risk of malignant progression; the detection of asymptomatic reflux brfore bariatric surgery; the role of non-GERD symptoms on the results of surgery; and the indications of Collis gastroplasty and choice of the type of fundoplication.

Laparoscopic resectional gastric bypass in patients with morbid obesity: experience on 112 consecutive patients

INTRODUCTION

Gastric bypass, without gastric resection of the distal excluded stomach, is the surgical treatment more frequently performed for morbid obesity. Several postoperative complications related to the “in situ” distal stomach have been described, and few cases of undetected gastric carcinoma located in this segment of stomach have been published. In this paper, we present our early postoperative results in patients submitted to laparoscopic gastric bypass with resection of distal stomach in patients with morbid obesity.

METHODS

One hundred twelve consecutive patients were included in this study. The mean body weight was 112.15±5.1 (range 78–145), and BMI was 40.5±6.9 kg/m2 (32.9–50.3). Patients were submitted to resectional gastric bypass by laparoscopic approach. The operative time was 133.7±29.1 min (range 120–240).

RESULTS

Postoperative complications occurred in 12 patients (10.7%) without any mortality. Early complications were observed in 11 patients while one patient presented a late complication, four patients were re-hospitalized, three of them without operation and other four of them were re-operated due to early (three patients) or late complication (one patient). One hundred patients (89.2%) were discharged at fourth postoperative day, seven patients remained in hospital between 5 and 10 days, and four patients after the tenth day due to complications. Leaks were observed in three patients. The histological study of the resected specimen was normal in only 8.9%.

CONCLUSIONS

Laparoscopic resectional gastric bypass presents very similar results compared to classic gastric bypass, without significant increase of morbidity, mortality, early and late postoperative results, and therefore, it is an option for the surgical treatment of morbid obesity in countries with high risk of gastric carcinoma.

[Indications for antireflux surgery: a clinical experience and review of the literature]

Antireflux laparoscopic surgery has excellent results in terms of improvement of symptoms, esophagitis, gastroesophageal sphincter competence and abnormal acid reflux. Indications for surgery are well established, however some of these are controversial. This is a review of the present indications for surgery in gastroesophageal reflux. The surgical indication should be the result of a complex clinical and laboratory work up. Patients with a clear cut surgical indication should be differentiated from those with doubtful indications, that require further analysis and those that are bad candidates for surgery. Young patients with macroscopic esophagitis, an incompetent sphincter, abnormal acid reflux test, that have a partial or negative response to treatment with proton pump inhibitors are those with the best surgical results. Bad candidates are patients with a psychiatric background, with atypical symptoms and those with a normal acid reflux test. In our experience with 935 patients, only 23% had a surgical indication.

Gastric leak after laparoscopic-sleeve gastrectomy for obesity

BACKGROUND

One of the most serious complications after laparoscopic sleeve gastrectomy (LSG) is gastric leak. Few publications exist concerning the treatment of gastric leak. We sought to determine by way of a prospective study the clinical presentation, postoperative course, and treatment of gastric leak after LSG for obesity.

METHODS

From October 2005 to August 2008, 214 patients with different degrees of obesity underwent LSG. During surgery, each patient received saline with methylene blue by way of nasogastric tube and had a drain placed. All patients underwent radiologic study with liquid barium sulphate on postoperative day 3.

RESULTS

Seven patients developed gastric leak. Leak in two patients (28.6%) was diagnosed by upper gastrointestinal tract (UGI) study. Two patients had type I leak (28.6%), and five patients had type II leak (71.4%). Four patients underwent reoperation. Three patients were managed medically with enteral or parenteral feeding; the drain was maintained in situ; and collections were drained by percutaneous punctions guided by computed axial tomography. Mean hospital length of stay was 28.8 days, and time to leakage closure was 43 days after surgery.

CONCLUSION

Different ways exist to manage gastric leak, depending on the magnitude of the collection and the clinical repercussions. When treatment necessitates reintervention and is performed early, suture repair is more likely to be successful. Leakage closure time will vary.

Inversed Y cardioplasty plus a truncal vagotomy-antrectomy and a Roux-en-Y gastrojejunostomy performed in patients with stricture of the esophagogastric junction after a failed cardiomyotomy or endoscopic procedure in patients with achalasia of the esophagus

Laparoscopic anterior cardiomyotomy in addition to anterior Dor's fundoplication is the procedure of choice for achalasia of the esophagus with approximately 95% success rate. Redo cardiomyotomy is complicated and associated with rerecurrence of dysphagia. Twelve patients with failed redo myotomy were clinically evaluated with radiology, endoscopy, and manometry in whom achalasia type III or IV was confirmed. We propose as treatment for these selected cases an inversed Y cardioplasty + truncal vagotomy, a partial distal gastrectomy and Roux-en-Y gastrojejunostomy in order to facilitate esophageal emptying and avoid the appearance of postoperative gastroesophageal reflux as a side effect of this procedure. One patient was reoperated on in order to enlarge the cardioplasty. Disappearance of dysphagia was confirmed in all patients. Three patients presented reflux symptoms and were treated with 20 mg of Omeprazole 20 twice/day. No food retention, erosive esophagitis, or Barrett's esophagus were observed. The mean resting pressure decreased from 24.9 +/- 8.5 mm Hg to 7.5 +/- 2.5 mm Hg (P = 0.0001). Furthermore, esophageal diameter decreased significantly after a 5-year follow-up. This procedure could be an option for treating patients in which repeated Heller operations have failed.

Postoperative results after laparoscopic approach for treatment of large hiatal hernias: is mesh always needed? Is the addition of an antireflux procedure necessary?

Laparoscopic approach has been suggested as the definitive treatment for large hiatal hernias. Reinforcement of the hiatoplasty and the need to perform antireflux surgery is still undergoing discussion. The purpose of this study was to evaluate the postoperative results, with special emphasis on the recurrence rate and reflux after surgery comparing the use or not of mesh reinforcement. This prospective study included 81 patients with a complete evaluation through a clinical questionnaire, barium sulfate radiologic evaluation, endoscopy, manometry, and 24-hour intraesophageal pH monitoring before and after a hiatoplasty with an antireflux procedure. Mesh reinforcement was used in 23 patients. Postoperative complications occurred in 11 patients (13.6%), without mortality. Recurrent hernia was observed in 10 patients without mesh reinforcement (12.3%), whereas those with mesh reinforcement showed no hiatal hernia recurrence (P = 0.33). Normal resting lower esophageal sphincter pressure was obtained after fundoplication in 87.2% of patients, and abnormal acid reflux was observed in 12.8% of patients after surgery. In conclusion, mesh reinforcement in patients with large Type IV could prevent recurrent hiatal hernias, and an antireflux procedure must be performed in order to avoid postoperative acid reflux.

Manometric changes of the lower esophageal sphincter after sleeve gastrectomy in obese patients

INTRODUCTION

Laparoscopic sleeve gastrectomy has been accepted as an option for surgical treatment of obesity. After surgery, some patients present reflux symptoms associated with endoscopic esophagitis, therefore PPI's treatment must be indicated.

PURPOSE

This study aims to evaluate the manometric characteristic of the lower esophageal sphincter (LES) before and after sleeve gastrectomy

MATERIAL AND METHOD

This prospective study includes 20 patients submitted to esophageal manometry in order to determine the resting pressure, and total and abdominal LES length before and after the sleeve gastrectomy. Statistical variations on the LESP were validated according to Student's "t" test.

RESULTS

Seventeen female and three male patients were included, with a mean age of 37.6 +/- 12.6 years. All patients reduced their body weight, from an initial BMI of 38.3 kg/m(2) to 28.2 kg/m(2) 6 months after surgery. No postoperative complications were observed in these patients. Preoperative mean LESP was 14.2 +/- 5.8 mmHg. Postoperative manometry decreased in 17/20 (85%), with a mean value of 11.2 +/- 5.7 mmHg (p = 0.01). Seven of them presented LESP <12 mmHg and ten patients <6 mmHg after the operation. Furthermore, the abdominal length and total length of the high pressure zone at the esophagogastric junction were affected.

CONCLUSION

A sleeve gastrectomy produces an important decrease in LES pressure, which can in turn cause the appearance of reflux symptoms and esophagitis after the operation due to a partial resection of the sling fibers during the gastrectomy.

Late results of the surgical treatment of 125 patients with short-segment Barrett esophagus

HYPOTHESIS

The results of surgical treatment of patients with long-segment Barrett esophagus (BE) have been extensively reported. However, few publications refer to the results of surgery 5 years after the fact among patients with short-segment BE. This study aimed to determine the late results of 3 surgical procedures in patients with short-segment BE by subjective and objective measurements.

DESIGN

Prospective, nonrandomized study starting on March 1, 1987, and ending on December 31, 2005.

SETTING

A prospective, descriptive study of a group of patients.

PATIENTS

A total of 125 patients with short-segment BE underwent 3 operations in different periods: duodenal switch plus highly selective vagotomy and antireflux technique in 31 patients, vagotomy plus partial gastrectomy and Roux-en-Y loop with antireflux surgery in 58 patients, and laparoscopic Nissen fundoplication in 36 patients.

MAIN OUTCOME MEASURES

Late subjective and objective outcomes of the 3 different surgical procedures.

RESULTS

No operative mortality and only 2 postoperative complications (1.6%) occurred. The regression from intestinal metaplasia to cardiac or oxyntocardiac mucosa occurred in 60.8% to 65.4% of the patients, at a mean time of 39 to 56 months after surgery. Visick grading showed Visick grade I or II in 86.3% to 100.0% of the patients. No progression to low- or high-grade dysplasia or adenocarcinoma occurred.

CONCLUSIONS

On the basis of these results, laparoscopic Nissen fundoplication seems to be the surgical option for patients with short-segment BE because it is less invasive, has fewer side effects, and produces good results in the long-term follow-up.

Enhancement in liver SREBP-1c/PPAR-alpha ratio and steatosis in obese patients: correlations with insulin resistance and n-3 long-chain polyunsaturated fatty acid depletion

Sterol receptor element-binding protein-1c (SREBP-1c) and peroxisome proliferator-activated receptor-alpha (PPAR-alpha) mRNA expression was assessed in liver as signaling mechanisms associated with steatosis in obese patients. Liver SREBP-1c and PPAR-alpha mRNA (RT-PCR), fatty acid synthase (FAS) and carnitine palmitoyltransferase-1a (CPT-1a) mRNA (real-time RT-PCR), and n-3 long-chain polyunsaturated fatty acid (LCPUFA)(GLC) contents, plasma adiponectin levels (RIA), and insulin resistance (IR) evolution (HOMA) were evaluated in 11 obese patients who underwent subtotal gastrectomy with gastro-jejunal anastomosis in Roux-en-Y and 8 non-obese subjects who underwent laparoscopic cholecystectomy (controls). Liver SREBP-1c and FAS mRNA levels were 33% and 70% higher than control values (P<0.05), respectively, whereas those of PPAR-alpha and CPT-1a were 16% and 65% lower (P<0.05), respectively, with a significant 62% enhancement in the SREBP-1c/PPAR-alpha ratio. Liver n-3 LCPUFA levels were 53% lower in obese patients who also showed IR and hipoadiponectinemia over controls (P<0.05). IR negatively correlated with both the hepatic content of n-3 LCPUFA (r=-0.55; P<0.01) and the plasma levels of adiponectin (r=-0.62; P<0.005). Liver SREBP-1c/PPAR-alpha ratio and n-3 LCPUFA showed a negative correlation (r=-0.48; P<0.02) and positive associations with either HOMA (r=0.75; P<0.0001) or serum insulin levels (r=0.69; P<0.001). In conclusion, liver up-regulation of SREBP-1c and down-regulation of PPAR-alpha occur in obese patients, with enhancement in the SREBP-1c/PPAR-alpha ratio associated with n-3 LCPUFA depletion and IR, a condition that may favor lipogenesis over FA oxidation thereby leading to steatosis.

Tumores gastrointestinales estromales (GIST): Experiencia del Servicio de Cirugía del Hospital Clínico de la Universidad de Chile entre 1999 y 2005

BACKGROUND

Gastrointestinal stromal tumors (GIST) are the most common mesenchymatous tumors of the digestive tract. The pathological diagnosis is based on microscopy and immunohistochemistiy.

AIM

To review the experience of our surgical unit in patients with GIST MATERIAL AND METHODS: Review of medical records of 15 patients (aged 66+/-13 years, 11 women), with a pathological diagnosis of GIST, treated between 1999 and 2005.

RESULTS

The main presenting symptoms were melena in 40%, hematemesis in 20%, abdominal pain in 60% and anemia in 13%. In only one patient, the tumor appeared as an incidentaloma. All patients underwent upper gastrointestinal endoscopy A CAT scan was done in 87%, a barium swallow in 60% and a digestive endosonography in 20%. Thirteen tumors were located in the stomach and two in the small bowel. Mean tumor diameter was 5.3+/-1.7 cm. Surgical management was a tumor resection in 40%, a partial gastrectomy in 27%, a total gastrectomy in 20% and an intestinal excision in the rest. Mean hospital stay was 6.9+/-4.2 days. No postoperative complications were recorded.

CONCLUSIONS

The main clinical presentation of GIST in this retrospective series was an upper gastrointestinal bleeding. Surgical treatment was devoid of complications.

Neosaxitoxin as a Local Anesthetic

Background

Neosaxitoxin is a phycotoxin that reversibly blocks the voltage-gated sodium channels at the neuronal level. Its activity results in blocking the axonal conduction, stopping the propagation of the nerve impulse. The objective of the present work was to evaluate neosaxitoxin as a local anesthetic in a human trial.

Methods

The authors conducted a randomized, double-blind, placebo-controlled trial with 10 healthy volunteers. Subcutaneous injections were made in the middle posterior skin of the calf: one leg received 50 microg neosaxitoxin, and the contra-lateral leg received placebo. The anesthetic effect was evaluated using a standardized human sensory and pain model. TSA II Neurosensory Analyzer (Medoc Ltd, Minneapolis, MN) and von Frey technique were used to evaluate five parameters: sensory threshold for warm and cold, pain thresholds for heat and cold, and mechanical touch perception threshold. Measurements were made 0, 1, 3, 6, 9, 12, 16, 24, and 48 h after the injections.

Results

For all the patients, effective and complete blocking of the evaluated parameters was obtained. As the blocking began to revert gradually, heat pain was the first to return to normal values after 3 h. Cold pain was the longest sensation abolished, achieving 24 h of blockade. The toxin was undetected in blood and urine samples. No adverse reactions to neosaxitoxin were detected.

Conclusions

Neosaxitoxin showed an effective local anesthetic effect when injected in the subcutaneous plane. The efficacy of a 50-microg dose of neosaxitoxin was shown. This is the first report of neosaxitoxin as a local anesthetic in a human trial.