Efficacy of Endoscopic Submucosal Dissection for Superficial Gastric Neoplasia in a Large Cohort in North America

BACKGROUND & AIMS

Endoscopic submucosal dissection (ESD) is a widely accepted treatment option for superficial gastric neoplasia in Asia, but there are few data on outcomes of gastric ESD from North America. We aimed to evaluate the safety and efficacy of gastric ESD in North America.

METHODS

We analyzed data from 347 patients who underwent gastric ESD at 25 centers, from 2010 through 2019. We collected data on patient demographics, lesion characteristics, procedure details and related adverse events, treatment outcomes, local recurrence, and vital status at the last follow up. For the 277 patients with available follow-up data, the median interval between initial ESD and last clinical or endoscopic evaluation was 364 days. The primary endpoint was the rate of en bloc and R0 resection. Secondary outcomes included curative resection, rates of adverse events and recurrence, and gastric cancer-related death.

RESULTS

Ninety patients (26%) had low-grade adenomas or dysplasia, 82 patients (24%) had high-grade dysplasia, 139 patients (40%) had early gastric cancer, and 36 patients (10%) had neuroendocrine tumors. Proportions of en bloc and R0 resection for all lesions were 92%/82%, for early gastric cancers were 94%/75%, for adenomas and low-grade dysplasia were 93%/ 92%, for high-grade dysplasia were 89%/ 87%, and for neuroendocrine tumors were 92%/75%. Intraprocedural perforation occurred in 6.6% of patients; 82% of these were treated successfully with endoscopic therapy. Delayed bleeding occurred in 2.6% of patients. No delayed perforation or procedure-related deaths were observed. There were local recurrences in 3.9% of cases; all occurred after non-curative ESD resection. Metachronous lesions were identified in 14 patients (6.9%). One of 277 patients with clinical follow up died of metachronous gastric cancer that occurred 2.5 years after the initial ESD.

CONCLUSIONS

ESD is a highly effective treatment for superficial gastric neoplasia and should be considered as a viable option for patients in North America. The risk of local recurrence is low and occurs exclusively after non-curative resection. Careful endoscopic surveillance is necessary to identify and treat metachronous lesions.

Systematic review with network meta-analysis: pharmacological prophylaxis against post-ERCP pancreatitis

BACKGROUND

The efficacy of many pharmacological agents for preventing post-ERCP pancreatitis (PEP) has been evaluated in randomised controlled trials (RCTs), but it is unclear which agent(s) should be used in clinical practice. Network meta-analyses of RCTs are used to simultaneously compare several agents to determine their relative efficacy and identify priority agents for comparison in future RCTs.

AIM

To evaluate pharmacological agents for the prevention of PEP by conducting a network meta-analysis of RCTs.

METHODS

We searched MEDLINE, EMBASE and Cochrane Library databases for RCTs that evaluated the efficacy of agents for preventing PEP. RCTs were simultaneously analysed using random-effects network meta-analysis under the Bayesian framework to identify the best agents. The efficacy of agents was ordered according to the probability of being ranked as any of the top three best performing agents.

RESULTS

The network meta-analysis included 99 RCTs evaluating 16 agents in 25 313 patients. Topical epinephrine (adrenaline) was the most efficacious agent with 85.9% probability of ranking among the top three agents, followed by nafamostat (51.4%), antibiotics (44.5%) and NSAIDs (42.8%). However, in a sensitivity analysis including only rectal NSAIDs, NSAIDs moved from fourth rank to second (58.1%). Patients receiving topical epinephrine, compared with placebo, had a 75% reduced risk of PEP (OR 0.25, 95% probability interval 0.06-0.66).

CONCLUSIONS

Topical epinephrine and rectal NSAIDs are the most efficacious agents for preventing post-ERCP pancreatitis, based on existing RCTs. Combinations of these agents, which act on different steps in the pathogenesis of post-ERCP pancreatitis, should be evaluated in future trials.

Long-term randomized controlled trial of a novel nanopowder hemostatic agent (TC-325) for control of severe arterial upper gastrointestinal bleeding in a porcine model

BACKGROUND AND STUDY AIM

Endoscopic therapy of brisk upper gastrointestinal bleeding remains challenging. A proprietary nanopowder (TC-325) has been proven to be effective in high pressure bleeding from external wounds. The efficacy and safety of TC-325 were assessed in a survival gastrointestinal bleeding animal model.

METHOD

10 animals were randomized to treatment or sham. All animals received intravenous antibiotics, H2-blockers and heparin (activated clotting time 2 × normal). In a sterile laparotomy the gastroepiploic vessels were dissected, inserted through a 1-cm gastrotomy, and freely exposed in the gastric lumen, and the exposed vessel lacerated by needle knife. The treatment group received TC-325 by a modified delivery catheter while the sham group received no endoscopic treatment. Time to hemostasis, and mortality at 60 minutes, 24 hours, 48 hours, and 7 days were noted. Necropsy was performed in all animals.

RESULTS

Spurting arterial bleeding was achieved in all animals. No control animal showed hemostasis within the first hour compared with 100 % (5 / 5) in the treatment arm (mean 13.8 minutes, P < 0.0079). Durable hemostasis was achieved with no evidence of rebleeding after 1 and 24 hours in 80 % (4 / 5) of the treated animals compared with none in the control group ( P < 0.0098). None of the control animals survived more than 6 hours. Necropsy at 1 week in treated animals revealed healed gastrotomy without foreign body granuloma or embolization to the lung or brain.

CONCLUSION

TC-325 is safe and highly effective in achieving hemostasis in an anticoagulated severe arterial gastrointestinal bleeding animal model.

Adhesion formation after peritoneoscopy with liver biopsy in a survival porcine model: comparison of laparotomy, laparoscopy, and transgastric natural orifice transluminal endoscopic surgery (NOTES)

BACKGROUND AND STUDY AIMS

Minimizing the invasiveness of operations by using natural orifice transluminal endoscopic surgery (NOTES) may reduce adhesion formation. The aim of the study was to compare rates of adhesion formation after peritoneoscopy with liver biopsy by laparotomy, laparoscopy, and transgastric NOTES.

MATERIALS AND METHODS

Experimental comparative survival study, at a university hospital. using 18 female pigs weighing 35 - 40 kg. Peritoneoscopy with liver biopsy was randomized to one of three groups: laparotomy, laparoscopy, and transgastric NOTES. Preoperative, operative, and postoperative care was standardized. Main outcome measures were: (i) survival and complication rates; (ii) assessment of adhesion formation using the Hopkins Adhesion Formation Score at necropsy (day 14).

RESULTS

100 % of pigs with laparotomy and 33.3 % with laparoscopy had adhesions compared with 16.7 % who underwent transgastric NOTES. Documented adhesion bands totals for each group were: transgastric NOTES 1; laparoscopy 4; laparotomy 17. Median adhesion formation scores were: laparotomy 2.5 (range 2 - 4), compared with laparoscopy 0.0 (0 - 2), and transgastric NOTES 0.0 (0 - 1) ( P < 0.001). Spearman coefficient analysis revealed that correlation between adhesion scores assigned by two investigators was excellent (r = 0.99, P < 0.001, 95 % confidence interval [CI] 0.9978 - 0.9996).

CONCLUSIONS

Although this was a short-term study, with a low number of animals, it showed that transgastric NOTES and laparoscopy are associated with statistically significantly lower rates of adhesion formation than open surgery when peritoneoscopy with liver biopsy is performed. Incidence and severity of adhesions were lowest with transgastric NOTES.

Severity of post-ERCP pancreatitis directly proportional to the invasiveness of endoscopic intervention: a pilot study in a canine model

BACKGROUND AND STUDY AIMS

Pancreatitis complicates 1% - 22% of endoscopic retrograde cholangiopancreatography procedures. The study aims were to develop a reproducible animal model of post-ERCP pancreatitis (PEP), and investigate the impact of endoscopic technique on severity of PEP.

PATIENTS AND METHODS

ERCP was carried out in six male hound dogs. Pancreatitis was induced by one of three escalating methods: 1) pancreatic acinarization with 20 - 30 mL of contrast; 2) acinarization + ductal balloon occlusion + sphincterotomy; 3) acinarization + intraductal synthetic bile injection + ductal balloon occlusion + sphincterotomy. Dogs 5 and 6 received a pancreatic stent. Necropsy was performed on postoperative day 5. All pancreatic specimens were graded by two blinded pathologists according to a validated scoring system. All dogs were compared with three control dogs.

RESULTS

Dogs 1 - 4 developed clinical pancreatitis and hyperamylasemia (11 736 vs. 722 U/L, P = 0.02). Total injury scores were significantly elevated compared with controls (6.85 vs. 1.06, P = 0.004). There was significant increase in acinar cell necrosis (0.86 vs. 0.06, P = < 0.001), and all other categories (except fibrosis) demonstrated elevated injury scores . Dogs 5 and 6 developed clinical pancreatitis without significant hyperamylasemia; total injury scores were elevated compared with controls (4.83 vs. 1.06, P = 0.01), but lower than in Dogs 1 - 4 (4.83 vs. 6.85, P = 0.25). There was escalating severity of pancreatic injury from Dogs 1 to 4 correlating with the method of endoscopic injury used.

CONCLUSION

Severity of PEP is directly proportional to invasiveness of endoscopic intervention. Pancreatic acinarization, even without balloon occlusion and sphincterotomy, can be used as a reliable animal model for future studies investigating therapy and prevention of disease.

Reliable gastric closure after natural orifice translumenal endoscopic surgery (NOTES) using a novel automated flexible stapling device

BACKGROUND

Reliable closure of the translumenal incision is one of the main challenges facing natural orifice translumenal endoscopic surgery (NOTES). This study aimed to evaluate the use of an automated flexible stapling device (SurgASSIST) for closure of the gastrotomy incision in a porcine model.

METHODS

A double-channel gastroscope was advanced into the stomach. A gastric wall incision was made, and the endoscope was advanced into the peritoneal cavity. After peritoneoscopy, the endoscope was withdrawn into the stomach. The SurgASSIST stapler was advanced orally into the stomach. The gastrotomy edges were positioned between the opened stapler arms using two endoscopic grasping forceps. Stapler loads with and without a cutting blade were used for gastric closure. After firing of the stapler to close the gastric wall incision, x-ray with contrast was performed to assess for gastric leakage. At the end of the procedure, the animals were killed for a study of closure adequacy.

RESULTS

Four acute animal experiments were performed. The delivery and positioning of the stapler were achieved, with technical difficulties mostly due to a short working length (60 cm) of the device. Firing of the staple delivered four rows of staples. Postmortem examination of pig 1 (when a cutting blade was used) demonstrated full-thickness closure of the gastric wall incision, but the cutting blade caused a transmural hole right at the end of the staple line. For this reason, we stopped using stapler loads with a cutting blade. In the three remaining animals (pigs 2-4), we were able to achieve a full-thickness closure of the gastric wall incision without any complications.

CONCLUSIONS

The flexible stapling device may provide a simple and reliable technique for lumenal closure after NOTES procedures. Further survival studies are currently under way to evaluate the long-term efficacy of gastric closure with the stapler after intraperitoneal interventions.

Preliminary pneumoperitoneum facilitates transgastric access into the peritoneal cavity for natural orifice transluminal endoscopic surgery: a pilot study in a live porcine model

BACKGROUND AND STUDY AIMS

Safe entrance into the peritoneal cavity through the gastric wall is paramount for the successful clinical introduction of natural orifice transluminal endoscopic surgery (NOTES). The aim of the study was to develop alternative safe transgastric access to the peritoneal cavity.

PATIENTS AND METHODS

We performed 11 survival experiments on 50-kg pigs. In sterile conditions, the abdominal wall was punctured with a Veress needle. The peritoneal cavity was insufflated with 2 L carbon dioxide (CO (2)). A sterile endoscope was introduced into the stomach through a sterile overtube; the gastric wall was punctured with a needle-knife; after balloon dilation of the puncture site, the endoscope was advanced into the peritoneal cavity. Peritoneoscopy with biopsies from abdominal wall, liver and omentum, was performed. The endoscope was withdrawn into the stomach. The animals were kept alive for 2 weeks and repeat endoscopy was followed by necropsy.

RESULTS

The pneumoperitoneum, easily created with the Veress needle, lifted the abdominal wall and made a CO (2)-filled space between the stomach and adjacent organs, facilitating gastric wall puncture and advancement of the endoscope into the peritoneal cavity. There were no hemodynamic changes or immediate or delayed complications related to pneumoperitoneum, transgastric access, or intraperitoneal manipulations. Follow-up endoscopy and necropsy revealed no problems or complications inside the stomach or peritoneal cavity.

CONCLUSIONS

Creation of a preliminary pneumoperitoneum with a Veress needle facilitates gastric wall puncture and entrance into the peritoneal cavity without injury to adjacent organs, and can improve the safety of NOTES.

A new stapler-based full-thickness transgastric access closure: results from an animal pilot trial

BACKGROUND AND STUDY AIMS

Reliable closure of the transluminal incision is the crucial step for natural orifice transluminal endoscopic surgery (NOTES) procedures. The aim of this study was to evaluate the feasibility and effectiveness of transgastric access closure with a flexible stapling device in a porcine survival model.

PATIENTS AND METHODS

We carried out four experiments (two sterile and two nonsterile) on 50 kg pigs. The endoscope was passed through a gastrotomy made with a needle knife and an 18-mm controlled radial expansion dilating balloon. After peritoneoscopy, a flexible linear stapling device (NOLC60, Power Medical Interventions, Langhorne, Pennsylvania, USA) was perorally advanced over a guide wire into the stomach, positioned under endoscopic guidance, and opened to include the site of gastrotomy between its two arms; four rows of staples were fired. One animal was sacrificed 24 hours after the procedure (progression of pre-existing pneumonia). The remaining animals were survived for 1 week and then underwent repeat endoscopy and postmortem examination.

RESULTS

Peroral delivery and positioning of the stapling device involved some technical difficulties, mostly due to the short length (60 cm) of the stapling device. The stapler provided complete leak-resistant gastric closure in all pigs. None of the surviving animals had any clinical signs of infection. Necropsy demonstrated an intact staple line with full-thickness healing of the gastrotomy in all animals. Histologic examination confirmed healing, but also revealed intramural micro-abscesses within the gastric wall after nonsterile procedure.

CONCLUSIONS

Gastrotomy closure with a perorally delivered flexible stapling device created a leak-resistant transmural line of staples followed by full-thickness healing of the gastric wall incision. Increasing the length of the instrument and adding device articulation will further facilitate its use for NOTES procedures.

Submucosal endoscopic esophageal myotomy: a novel experimental approach for the treatment of achalasia

BACKGROUND AND STUDY AIMS

The most permanent method of treating achalasia is a surgical myotomy. Because of the requirement for a mucosal incision and the risk of perforation, this procedure has not generally been approached endoscopically. We hypothesized that we could perform a safe and robust myotomy by working in the submucosal space, accessed from the esophageal lumen.

MATERIALS AND METHODS

Four pigs were used for this experiment. Baseline lower esophageal sphincter (LES) pressures were recorded and the pigs underwent upper endoscopy using a standard endoscope. A submucosal saline lift was created approximately 5 cm above the LES and a small nick was made in the mucosa in order to facilitate the introduction of a dilating balloon. After dilation, the scope was introduced over the balloon into the submucosal space and advanced toward the now visible fibers of the LES. The circular layer of muscle was then cleanly incised using an electrocautery knife in a distal-to-proximal fashion, without complications. The scope was then withdrawn back into the lumen and the mucosal defect was closed with endoscopically applied clips. The entire procedure took less than 15 minutes. Manometry was repeated on day 5 after the procedure and the animals were euthanized on day 7.

RESULTS

LES pressures fell significantly from an average of 16.4 mm Hg to an average of 6.7 mm Hg after the myotomy. The necropsy examinations revealed no evidence of mediastinitis or peritonitis.

CONCLUSIONS

Endoscopic submucosal esophageal myotomy is feasible, safe, and effective in the short term. It has the potential for being useful in patients with achalasia. The submucosal space is a novel and potentially important field of operation for endoscopic procedures.

Submucosal endoscopic esophageal myotomy: a novel experimental approach for the treatment of achalasia

BACKGROUND AND STUDY AIMS

The most permanent method of treating achalasia is a surgical myotomy. Because of the requirement for a mucosal incision and the risk of perforation, this procedure has not generally been approached endoscopically. We hypothesized that we could perform a safe and robust myotomy by working in the submucosal space, accessed from the esophageal lumen.

MATERIALS AND METHODS

Four pigs were used for this experiment. Baseline lower esophageal sphincter (LES) pressures were recorded and the pigs underwent upper endoscopy using a standard endoscope. A submucosal saline lift was created approximately 5 cm above the LES and a small nick was made in the mucosa in order to facilitate the introduction of a dilating balloon. After dilation, the scope was introduced over the balloon into the submucosal space and advanced toward the now visible fibers of the LES. The circular layer of muscle was then cleanly incised using an electrocautery knife in a distal-to-proximal fashion, without complications. The scope was then withdrawn back into the lumen and the mucosal defect was closed with endoscopically applied clips. The entire procedure took less than 15 minutes. Manometry was repeated on day 5 after the procedure and the animals were euthanized on day 7.

RESULTS

LES pressures fell significantly from an average of 16.4 mm Hg to an average of 6.7 mm Hg after the myotomy. The necropsy examinations revealed no evidence of mediastinitis or peritonitis.

CONCLUSIONS

Endoscopic submucosal esophageal myotomy is feasible, safe, and effective in the short term. It has the potential for being useful in patients with achalasia. The submucosal space is a novel and potentially important field of operation for endoscopic procedures.

Hybrid minimally invasive surgery--a bridge between laparoscopic and translumenal surgery

BACKGROUND

The peroral transluminal approach to the peritoneal cavity appears safe, feasible, and may further reduce the invasiveness of surgery. However, flexible endoscopes have multiple limitations inside the peritoneal cavity, which can potentially be overcome by blending the use of both a laparoscope and a flexible upper endoscope--a hybrid approach. The goal of the present study was to evaluate a hybrid minimally invasive technique for cholecystectomy in a porcine model.

METHODS

Hybrid cholecystectomies were performed in acute experiments on 50-kg pigs under general anesthesia. Pneumoperitoneum was created with a Veress needle, and a laparoscopic 10-mm port was inserted. Under laparoscopic observation, the gastric wall incision was done with an endoscopic needle-knife and sphincterotome, and the upper endoscope was advanced into the peritoneal cavity. A laparoscopic 10-mm port was inserted into the right upper quadrant of the abdomen for gallbladder traction to facilitate exposure of the cystic duct and artery. Via the biopsy channel of the flexible endoscope, and using a knife with an isolated tip, a needle knife, and clips, both the cystic duct and artery were identified, clipped, and transected. The gallbladder itself was then dissected and retracted through the mouth, and the gastric wall incision was closed with endoscopic clips.

RESULTS

Five hybrid cholecystectomies were performed without complications. The laparoscopic port enabled a stable pneumoperitoneum, good traction and counter-traction, and improved spatial orientation and visualization. Necropsy did not reveal any intraperitoneal complications.

CONCLUSIONS

The hybrid approach increases safety of initial gastric puncture and gastric wall incision, improves orientation and navigation of the flexible endoscope inside the peritoneal cavity, simplifies peroral transgastric cholecystectomy, and could be used to decrease invasiveness of laparoscopic surgery and to facilitate development and clinical introduction of transgastric endoscopic procedures.

ELECTRONIC SUPPLEMENTARY MATERIAL

The online version of this article (doi:10.1007/s00464-007-9329-2) contains supplementary material, which is available to authorized users.

The utility of contrast-enhanced endoscopic ultrasound in monitoring ethanol-induced pancreatic tissue ablation: a pilot study in a porcine model

BACKGROUND AND STUDY AIMS

Pancreatic ablation is gaining popularity for the treatment of focal pancreatic lesions. The aim of our study was to evaluate local effects of intrapancreatic alcohol injection and the utility of contrast-enhanced endoscopic ultrasound (EUS) for its monitoring in a porcine model.

METHODS

We performed four survival experiments on 50-kg pigs. Under linear EUS guidance, 0.5 mL of 50% ethanol plus purified carbon particle solution (GI Spot) was injected into the pancreatic body to create a focal area of pancreatic necrosis. The animals survived for 24-48 hours (pigs # 1, # 2, and # 3) and 7 days (pig # 4). EUS was then repeated with and without perflutren lipid microspheres (Definity) administration through the peripheral vein. Standard and microsphere-enhanced images of the pancreas were compared. Afterwards the animals were euthanized for necropsy.

RESULTS

Alcohol injection caused focal pancreatic necrosis, which was barely seen by standard EUS as a subtle hypoechoic lesion 1 cm in diameter. Color and power Doppler EUS of this region did not reveal any blood flow. After intravenous injection of microspheres, color Doppler EUS revealed marked contrast enhancement of normal pancreatic parenchyma with a clearly delineated avascular alcohol-treated area, which on postmortem examination corresponded to the discrete necrotic area marked with carbon particles.

CONCLUSIONS

EUS-guided alcohol injection consistently causes focal areas of pancreatic necrosis. Contrast-enhanced EUS with microspheres improves visualization of altered pancreatic vascular perfusion and can be used to facilitate detection of small pancreatic lesions and its follow-up post-ablation.

Peroral transgastric endoscopic primary repair of a ventral hernia in a porcine model

BACKGROUND AND STUDY AIMS

Multiple studies have demonstrated the feasibility of peroral transgastric endoscopic procedures in animal models. The aim of the study was to evaluate the feasibility of a peroral transgastric endoscopic approach to repair abdominal wall hernias.

PATIENTS AND METHODS

We performed acute experiments under general anesthesia with endotracheal intubation using 50-kg pigs. Following peroral intubation an incision of the gastric wall was made and the endoscope was advanced into the peritoneal cavity. An internal anterior abdominal wall incision was performed with a needle knife to create an animal model of a ventral hernia. After hernia creation an endoscopic suturing device was used for primary repair of the hernia. After completion of the hernia repair the endoscope was withdrawn into the stomach and the gastric wall incision was closed with endoscopic clips. Then the animals were killed for necropsy.

RESULTS

Two acute experiments were performed. Incision of the gastric wall was easily achieved with a needle knife and a pull-type sphincterotome. A large (3 x 2 cm) defect of the abdominal wall (ventral hernia model) was closed with five or six sutures using the endoscopic suturing device. Postmortem examination revealed complete closure of the hernia without any complications.

CONCLUSIONS

Transgastric endoscopic primary repair of ventral hernias in a porcine model is feasible and may be technically simpler than laparoscopic surgery.

Comparison of intraabdominal pressures using the gastroscope and laparoscope for transgastric surgery

BACKGROUND

The peroral transgastric endoscopic approach for intraabdominal procedures appears to be feasible, although multiple aspects of this approach remain unclear. This study aimed to measure intraperitoneal pressure in a porcine model during the peroral transgastric endoscopic approach, comparing an endoscopic on-demand insufflator/light source with a standard autoregulated laparoscopic insufflator.

METHODS

All experiments were performed with 50-kg female pigs under general anesthesia. A standard upper endoscope was advanced perorally through a gastric wall incision into the peritoneal cavity. The peritoneal cavity was insufflated with operating room air from an endoscopic light source/insufflator. Intraperitoneal pressure was measured by three routes: (1) through the endoscope biopsy channel, (2) through a 5-mm transabdominal laparoscopic port, and (3) through a 16-gauge Veress needle inserted into the peritoneal cavity through the anterior abdominal wall. The source of insufflation alternated between on-demand manual insufflation through the endoscopic light source/insufflator using room air and a standard autoregulated laparoscopic insufflator using carbon dioxide (CO(2)).

RESULTS

Six acute experiments were performed. Intraperitoneal pressure measurements showed good correlation regardless of measurement route and were independent of the type of insufflation gas, whether room air or CO(2). On-demand insufflation with the endoscopic light source/insufflator resulted in a wide variation in pressures (range, 4-32 mmHg; mean, 16.0 +/- 11.7). Intraabdominal pressures using a standard autoregulated laparoscopic insufflator demonstrated minimal fluctuation (range, 8-15 mmHg; mean, 11.0 +/- 2.2 mmHg) around a predetermined value.

CONCLUSION

Use of an on-demand unregulated endoscopic light source/insufflator for translumenal surgery can cause large variation in intraperitoneal pressures and intraabdominal hypertension, leading to the risk of hemodynamic and respiratory compromise. Safety may favor well-controlled intraabdominal pressures achieved with a standard autoregulated laparoscopic insufflator.

An endoscopically implantable device stimulates the lower esophageal sphincter on demand by remote control: a study using a canine model

BACKGROUND AND STUDY AIMS

Implantable microstimulators (IMS) have been used in a variety of medical conditions. Selective stimulation to increase lower esophageal sphincter (LES) pressure may be useful in the control of gastroesophageal reflux disease. We evaluated on-demand stimulation of the LES with an endoscopically implanted microstimulator.

MATERIALS AND METHODS

We performed acute experiments in three 30-kg dogs. After LES manometry, a 3.3 mm x 28 mm microstimulator (the Bion) was implanted into the LES. Manometry was repeated with and without IMS stimulation to record the changes in LES pressure. Stimulation amplitude was varied from 3 mA to 10 mA, with a fixed frequency of 20 Hz and a pulse width of 200 microsec.

RESULTS

The mean LES pressures prior to IMS implantation in the three dogs were 13.0 mm Hg, 5.0 mm Hg, and 14.9 mm Hg. The mean pressures were not significantly changed by IMS placement. There were no documented changes in LES pressure when the amplitude of stimulation was less than 8 mA. After stimulation of the IMS at a setting of 10 mA in dogs 1 and 2 and at 8mA in dog 3, however, the resultant LES pressures were 62.1 mm Hg, 35.1 mm Hg, and 26.8 mm Hg respectively, more than three times higher than post-implantation baseline levels (P < 0.02).

CONCLUSIONS

The LES pressure can be increased using an on-demand microstimulator. The implantation procedure is minimally invasive, represents a novel therapeutic approach to gastroesophageal reflux disease, and may have therapeutic potential for other gastrointestinal motility disorders.

Is blood the ideal submucosal cushioning agent? A comparative study in a porcine model

BACKGROUND AND STUDY AIMS

Creation of a submucosal cushion before endoscopic mucosal resection (EMR) significantly reduces perforation risk. We evaluated six solutions as cushioning agents in live pigs.

MATERIAL AND METHODS

5 ml of normal saline, normal saline plus epinephrine, albumin 12.5 %, albumin 25 %, hydroxypropyl methylcellulose, and the pig's own whole blood were endoscopically injected into the porcine esophageal submucosa. Blood was obtained from a peripheral vein immediately before injection. Injections were made every 4 cm from the gastroesophageal junction. The time from completion of the injection to disappearance of the cushion was recorded. Endoscopy was repeated at 48 hours post injection. Two EMRs were performed after blood injection. Statistical analysis employed one-way analysis of variance followed by pairwise T test comparisons using the Bonferroni correction.

RESULTS

Five animal experiments were completed. The mean time to dissipation of the submucosal cushion was shortest for saline plus epinephrine sites (2.87 minutes, SD 2.21) followed by the saline (4.8 minutes, SD 1.56), albumin 12.5 % (5.68 minutes, SD 3.48), albumin 25 % (7.83 minutes, SD 2.02), hydroxypropyl methylcellulose (9.77 minutes, SD 1.55), and blood sites (38.6 minutes, SD 6.07). Injection of blood resulted in significantly longer mucosal elevation than any other solution ( P < 0.0007). Blood from the cushion did not hamper visualization and facilitated EMR.

CONCLUSION

Blood produces the most durable cushion compared with standard agents, also having the advantages of being readily available and without cost. Albumin 25 % provides as durable a cushion as hydroxypropyl methylcellulose.

Effect of a novel pancreatic stent design on short-term pancreatic injury in a canine model

BACKGROUND AND STUDY AIMS

Attempts to address the problem of injury to the pancreas by indwelling pancreatic stents are limited by our lack of knowledge of the pathogenesis of stent-induced injury and its relationship to stent morphology and the duration of stenting. The aim of our study was to evaluate pancreatic injury induced by 1 week of stenting with a 5F indwelling pancreatic stent of novel design, the "wing stent."

METHODS

Pancreatic stents (5F) were placed surgically in eight dogs; wing stents (WS-5F) were used in four dogs and conventional stents (CS-5F) in another four. Two dogs underwent duodenotomy without stent placement (controls). The pancreas was harvested for microscopy at 1 week. A pathologist who was unaware of the source of the specimens graded the pancreatic injury.

RESULTS

Although pancreatic injury was observed in both the CS-5F and WS-5F groups after 1 week of indwelling pancreatic stenting, it was considerably less severe in the WS-5F group compared with the CS-5F group (1.01 +/- 0.10 vs. 1.63 +/- 0.14, P < 0.01). All components of pancreatic injury were affected, with the most dramatic differences noted in inflammation, fibrosis, and edema. The differences were most marked in the stented segment ( P < 0.001) and in the upstream segment of the pancreas ( P < 0.05).

CONCLUSIONS

Indwelling conventional pancreatic stents can cause significant pancreatic injury even when left in place for only 1 week. A wing design can significantly ameliorate stent-induced changes.

Transgastric endoscopic splenectomy: is it possible?

BACKGROUND

We have previously reported the feasibility of diagnostic and therapeutic peritoneoscopy including liver biopsy, gastrojejunostomy, and tubal ligation by an oral transgastric approach. We present results of per-oral transgastric splenectomy in a porcine model. The goal of this study was to determine the technical feasibility of per-oral transgastric splenectomy using a flexible endoscope.

METHODS

We performed acute experiments on 50-kg pigs. All animals were fed liquids for 3 days prior to procedure. The procedures were performed under general anesthesia with endotracheal intubation. The flexible endoscope was passed per orally into the stomach and puncture of the gastric wall was performed with a needle knife. The puncture was extended to create a 1.5-cm incision using a pull-type sphincterotome, and a double-channel endoscope was advanced into the peritoneal cavity. The peritoneal cavity was insufflated with air through the endoscope. The spleen was visualized. The splenic vessels were ligated with endoscopic loops and clips, and then mesentery was dissected using electrocautery.

RESULTS

Endoscopic splenectomy was performed on six pigs. There were no complications during gastric incision and entrance into the peritoneal cavity. Visualization of the spleen and other intraperitoneal organs was very good. Ligation of the splenic vessels and mobilization of the spleen were achieved using commercially available devices and endoscopic accessories.

CONCLUSIONS

Transgastric endoscopic splenectomy in a porcine model appears technically feasible. Additional long-term survival experiments are planned.

Developing an animal model of massive ulcer bleeding for assessing endoscopic hemostatic devices

BACKGROUND

Existing animal models of ulcerative bleeding are not suitable for endoscopic investigation. We describe a new porcine model of massive arterial bleeding in the stomach and its use for assessing a novel endoscopic suturing device.

METHODS

Two animal models were investigated. In model 1, the short gastric artery (mean diameter 2 mm) was divided near its gastric end. A mucosal defect was created near the greater curve and the divided artery was brought into the lumen of the stomach through a submucosal tunnel. An inflatable plastic cuff was placed around the base of the artery. Cuff deflation led to massive bleeding. In model 2, the short gastric artery was carefully exposed along a segment of 2 cm on the side facing the stomach. It was then anchored to a small gastrostomy made at the posterior wall near the vessel. At endoscopy an ulcer-like lesion could be seen with a pulsatile vessel at the base and brisk bleeding could be started by cutting a hole in the artery using endoscissors. The pigs were heparinized by an intravenous bolus of 110-300 units per kilogram, in both models. A prototype suturing device, the Eagle Claw, was inserted using a gastroscope and the curved needle was driven around the bleeding artery. Extracorporeal knotting or intracorporeal ligation was done endoscopically.

RESULTS

Pulsatile arterial bleeding was successfully created in four pigs using model 1, and in another four pigs using model 2. Model 2 was more reproducible and less time-consuming to create. Endoscopic suturing controlled arterial bleeding in five out of eight pigs with a single stitch and in another three pigs with an additional stitch.

CONCLUSION

This animal model provides reproducible massive hemorrhage suitable for endoscopic studies. Control of gastric bleeding from large arteries by endoscopic suturing is possible.

Assessing the adequacy of endoscopically tied knots: a functional approach

BACKGROUND AND STUDY AIMS

Endoscopic intracorporeal knots have potentially enormous applications in endoscopic surgery. We describe a method for testing the security of various types of endoscopically tied knots using a vessel perfusion manometer system.

METHODS

A 4-cm segment of porcine splenic artery was placed on the mucosal surface of a pig stomach. The two ends of the vessel were brought out through the gastric wall and connected to a two-way manometer. One end was also joined to a pressure infusion bag. The stomach was mounted in an Erlangen training model. A long 3/0 nylon thread, previously introduced into the submucosal layer of the stomach and encircling the vessel, was brought out from the mouth. Three-throw square knots, Mayo knots, "surgeon's" knots and five-throw square knots were tied and pushed into place using a cap attached to a gastroscope. The pressure at the two ends of the artery was compared. If the pressure could be increased to over 200 mm Hg at one end without a change in the other, the knot was considered secure.

RESULTS

Each type of knot was tested 12 times under endoscopic vision. The range for mean knotting time was 3.4 - 4.5 minutes. Five-throw knots took significantly longer to tie than three-throw knots (P < 0.005). There was one loose knot in each of the three-throw and Mayo groups, and three each in the "surgeon's" and five-throw groups (P > 0.05).

CONCLUSIONS

This system is a reliable model for testing intracorporeal knots tied endoscopically. A three-half-hitches square knot with 3/0 nylon, tied using a flexible endoscope and knot-tightening cap, can withstand pressure up to 200 mm Hg.

Transoral obesity surgery: endoluminal gastroplasty with an endoscopic suture device

BACKGROUND AND STUDY AIMS

Surgical creation of a small gastric pouch with a restricted outlet is a well-established option for the treatment of morbid obesity. This report describes initial experience with endoscopic transoral stomach partition using a newly designed suturing apparatus.

MATERIALS AND METHODS

A fresh porcine stomach was placed in the Erlangen model. A prototype suture device, incorporating a curved needle and an intracorporeal tightening mechanism, was used in this procedure. A long fishing line was first introduced into the stomach, with the two ends left outside. The suturing device, premounted outside a standard gastroscope, was inserted into the stomach and delivered several stitches attaching the fishing line to both the anterior and posterior walls along the line for the stomach to be partitioned. Five throws of half-hitches were tied onto the fishing line extracorporeally and separately pushed into place, creating a gastric pouch just below the esophagogastric junction. A flexible sheath of 8 cm long was then put on one side of the fishing line and pushed into the stomach. Additional extracorporeal knots were tied on the fishing line, forming a restrictive ring at the outlet of the pouch. The ring was then anchored to the stomach wall with similar endosutures.

RESULTS

The proximal gastric pouch, with an estimated volume of approximately 100 ml, was successfully created with a restrictive band at its outlet. All of the stitches were securely sutured, with consistent penetration of the muscular layer of the stomach wall.

CONCLUSIONS

In a bench model, it is technically possible to accomplish transoral gastroplasty endoscopically with an intraluminal suturing device. Further live animal studies will be needed in order to confirm the efficacy and safety of this procedure before clinical application.

Oddi's sphincter dysfunction

In the last decade, the controversy of sphincter of Oddi dysfunction (SOD) as a clinical entity has abated. The challenges facing clinicians caring for patients with suspected SOD are to effectively and safely diagnose and treat these patients. Sphincter of Oddi (SO) manometry (SOM) remains the gold standard for the diagnosis of SO dysfunction SOD. Several non-invasive screening tests for patients with pancreaticobiliary pain have been developed because SOM is associated with significant complications. Ultrasonography is useful for screening of organic pancreaticobiliary diseases but not for functional ones. Although magnetic resonance cholangiopancreatography (MRCP) is a safe, noninvasive method of examining the pancreaticobiliary tree abnormalities, it may currently have limited use in patients with suspected SOD. Quantitative hepatobiliary scintigraphy (QHBS) appears to become a promising method for identification of patients with biliary type SOD, and it should be employed prior to invasive diagnostic tests. ERCP for patients with type III SOD must be coupled with diagnostic SOM of both biliary and pancreatic sphincters since there are a high concordance of dual sphincter dysfunction. SOM is currently the gold standard of choice for evaluating SOD is the best predictor of outcome from sphincter ablation in type II and type III patients regardless of whether there is pancreatic or biliary SOD. In pancreatic SOD patients, biliary sphincterotomy alone may be inadequate for a treatment for some pancreatic type II patients. Medical therapy for SOD using smooth muscle relaxants has been disappointing and surgical therapy may play a role in limited number of cases that failed endoscopic therapy. Endoscopic intrasphincteric injection of Botulinum toxin is effective in patients with SOD and has minimal risks but it provides short-term efficacy. It may play a role as a first line diagnostic challenge, predicting which patient may ultimately respond to endoscopic sphincterotomy.

Endoscopic findings predict the histologic diagnosis in gastrointestinal graft-versus-host disease

BACKGROUND AND STUDY AIMS

Graft-versus-host disease (GvHD) of the gastrointestinal tract is a major cause of morbidity and mortality after allogeneic bone marrow transplantation (BMT). Whether endoscopic findings predict the histologic diagnosis of GvHD in the gastrointestinal tract remains controversial. We performed a study to determine the diagnostic accuracy of macroscopic endoscopy findings in the diagnosis of acute and chronic histologically proven gastrointestinal GvHD (GI-GvHD).

PATIENTS AND METHODS

Endoscopic images from the intestinal mucosa of post-BMT patients were blindly graded as positive or negative for GI-GvHD and compared with corresponding histological findings, which were used as the gold standard.

RESULTS

44 BMT patients were referred for 96 endoscopic evaluations. Using 162 endoscopy-biopsy pairs, a positive association between endoscopic grading and histologic grading of GI-GvHD (odds ratio [OR] = 11.97, 95% CI 3.86, 37.16) was observed. Endoscopic diagnosis correctly predicted histologic diagnosis in both acute and chronic GI-GvHD (OR = 9.3 vs. 23.1, P = 0.31).

CONCLUSIONS

The diagnostic accuracy of endoscopy was high in both acute and chronic histologically proven GI-GvHD. Accurate diagnosis of GI-GvHD might be obtained with mucosal biopsies from either the upper or lower gastrointestinal tract. Endoscopy may play a significant role in establishing early diagnosis and treatment for GI-GvHD in patients following BMT, but histologic evaluation of the gastrointestinal mucosa is needed to confirm the final diagnosis.

Gallstones and biliary disease

Gallstones are common in the US and western countries. This article describes the pathogenesis of gallstone formation and the clinical manifestations and current approaches to diagnosis and treatment of the most common clinical conditions caused by gallstones: biliary colic, acute cholecystitis, choledocholithiasis, and acute gallstone pancreatitis. The role of widely used imaging techniques (transabdominal ultrasound, CT scan, MR imaging, and MRCP) and diagnostic and therapeutic endoscopy (endoscopic ultrasound, ERCP) is emphasized. This article is intended mainly for general practitioners, primary care physicians, and other specialists providing medical care to patients with gallstones and their complications.

Efficacy of biliary scintigraphy in suspected sphincter of Oddi dysfunction

Sphincter of Oddi dysfunction (SOD) can pose diagnostic challenges for the physician. SOD is classified into types I, II, and III, but clinical outcome after sphincterotomy for suspected types II and III SOD has been unpredictable. Therefore, accurate diagnosis of types II and III SOD is important because of the increased risk of sphincterotomy in patients with SOD. Endoscopic sphincter of Oddi manometry (ESOM) is the gold standard for diagnosis of SOD; however, it is associated with significant morbidity and is not an appropriate screening test. Quantitative hepatobiliary scintigraphy (QHBS) has demonstrated good sensitivity as a screening test for SOD in patients following cholecystectomy; however, studies using this methodology are criticized for poor design and patient selection. Recent publications address these criticisms and provide evidence that QHBS and ESOM are comparable diagnostic tools after exclusion of organic biliary obstruction. QHBS can effectively replace invasive ESOM in the diagnostic algorithm of SOD.

What are the long-term results of endoscopic pancreatic sphincterotomy?

BACKGROUND

Endoscopic pancreatic sphincterotomy has been touted as effective therapy for chronic pancreatitis and unexplained abdominal pain resulting from pancreatic sphincter dysfunction. Although short-term data are encouraging, there are no reports on how these patients fare beyond the first few months.

METHODS

We performed a retrospective review of records on all patients who had pancreatic sphincterotomy during a 4-year period between August 1992 and November 1996. Chronic pancreatitis was diagnosed by pancreatography. Patients were evaluated for symptomatic response to pancreatic sphincterotomy and clinical improvement was defined as greater than 50% reduction in the magnitude of pain.

RESULTS

Fifty-five patients had pancreatic sphincterotomy including patients with (n = 40) and without (n = 15) chronic pancreatitis. After a median follow-up of 16 months, 60% of all patients reported improvement of pain scores (3.6 +/- 3.4 vs. 8.8 +/- 1.8; p < 0.01) with the best response in patients without evidence of chronic pancreatitis. Complications of pancreatic sphincterotomy included pancreatitis in 5 patients (9%), bleeding in 2 (3.6%) and early stent occlusion in 5 patients (9%). There were no deaths.

CONCLUSIONS

In a subgroup of patients with pancreatic sphincter dysfunction, endoscopic pancreatic sphincterotomy results in significant sustained clinical improvement.

Diagnosis and management of cholangiocarcinoma in primary sclerosing cholangitis

Cholangiocarcinoma remains difficult to diagnose and is a major cause of death in patients with primary sclerosing cholangitis. Recently serum carcinoembryonic antigen and carbohydrate antigen 19-9 (CA 19-9) levels have been reported to improve diagnostic accuracy in patients with cholangiocarcinoma and primary sclerosing cholangitis. We reviewed our experience with cholangiocarcinoma complicating primary sclerosing cholangitis to identify clinical factors associated with cholangiocarcinoma in patients with primary sclerosing cholangitis and to determine the appropriate management of patients with confirmed or suspected cholangiocarcinoma. Between 1984 and 1997, 25 patients (18%) were diagnosed with cholangiocarcinoma among 139 patients with primary sclerosing cholangitis. The diagnosis of primary sclerosing cholangitis was made coincident with the diagnosis of cholangiocarcinoma in 12 patients and preceded it by a mean of 62 months in the remaining 13 patients. The incidence of inflammatory bowel disease was higher (P <0.05) in patients with cholangiocarcinoma (80% vs. 61%). Nine patients (36%) with cholangiocarcinoma were managed with either extrahepatic bile duct resection and/or partial hepatic resection (n = 5) or liver transplantation (n = 4), and the remaining 16 patients were unresectable at presentation. Serum CA 19-9 was elevated in all six patients with cholangiocarcinoma who were analyzed and in none of the eight patients without cholangiocarcinoma who were tested (P <0.01). Actuarial 1- and 3-year survival rates in the resected patients (56% and 28%, respectively) were significantly longer (P <0. 02) than in the unresected patients (13% and 0%, respectively). The 10-year actuarial mortality rates for cholangiocarcinoma among all 139 patients was 25%. In summary, cholangiocarcinoma was the leading cause of death in patients with primary sclerosing cholangitis and was often diagnosed concurrently with or within months of its diagnosis. Early liver transplantation for patients with primary sclerosing cholangitis will not reduce the incidence of cholangiocarcinoma-related mortality in these patients.

Endoscopic cryotherapy: experimental results and first clinical use

BACKGROUND

Cryotherapy or the application of extreme cold has many potential applications in gastroenterology including tissue destruction and hemostasis but until now its development has been prevented by the lack of a delivery device suitable for use through the endoscope. We report here our experience with prototype devices using both liquid nitrogen driven by a cryosurgical system and cryogenic refrigerants (nitrous oxide and carbon dioxide) at or near ambient temperature.

METHODS

Cryotherapy was applied to the distal esophageal mucosa of dogs via a flexible catheter passed through an upper endoscope. In other dogs, cryotherapy was used for hemostasis in a bleeding ulcer model. The procedure was also used for palliation in a 58-year-old man with unresectable adenocarcinoma of the stomach with pyloric channel obstruction.

RESULTS

Freezing of the superficial mucosa was nearly instantaneous. All dogs survived the procedure and appeared to thrive. Histologic evaluation revealed significant necrosis of the superficial epithelial layer accompanied by a fibrinocellular infiltrate on the surface. These markers of acute injury subside by the fourth to sixth day and are replaced by regenerating epithelium, a process that is virtually complete by day 10. In the hemostasis experiments, bleeding ceased immediately after cryospraying of the lesions but resumed on thawing in most cases. Application of cryotherapy in the patient resulted in reduction of the pyloric mass with no immediately apparent adverse effects.

CONCLUSIONS

These data, although preliminary, demonstrate the feasibility of endoscopic cryotherapy using a simple hand-held device. This device has broad potential for use in gastroenterology including ablation of superficial epithelium, debulking of large tumors and hemostasis.

Pain: the overlooked symptom in gastroparesis

OBJECTIVE

Abdominal pain has not been reported generally as a significant feature of the clinical presentation of patients with gastroparesis.

METHODS

Using a standardized questionnaire, we analyzed the clinical features of 28 consecutive patients referred with established or suspected gastroparesis over a 4-yr period. The diagnosis of gastroparesis was supported by abnormalities in gastric emptying studies (GES), electrogastrography (EGG), or upper endoscopy (EGD). Diagnostic tests were reviewed.

RESULTS

A total of 12 male (mean age 39.5 yr) and 18 female patients (mean age 39.6 yr) were included in this study. These patients had been symptomatic for an average of 37.8 months before their referral to our center. Seven of these patients had insulin-dependent diabetes. Idiopathic gastroparesis was present in more than half of the patients. The symptom profile of the 28 patients was as follows: nausea, 92.9%; abdominal pain, 89.3%; early satiety, 85.7%; and vomiting, 67.9%. The pain was described as burning, vague, or crampy in nature. Only 36% localized to the upper abdomen. In all, 60% of patients complained of postprandial pain, whereas 80% complained of nocturnal pain that interfered with their normal sleeping pattern. In general, pain responded poorly or not at all to prokinetic agents.

CONCLUSIONS

Nausea and abdominal pain are the most common complaints of patients with gastroparesis. In 80% of patients, GES and EGG correlated positively.

Clinical usefulness of 3% hydrogen peroxide in acute upper GI bleeding: a pilot study

BACKGROUND

A major problem in the endoscopic management of acute upper gastrointestinal (GI) bleeding is the presence of blood and clots overlying the bleeding source, preventing visualization of the lesion. A simple alternative is to alter the characteristics of blood such that it not only becomes easier to remove but also becomes translucent. We report the results of a pilot study on the use of hydrogen peroxide in patients with acute upper GI bleeding.

METHODS

Patients with acute upper GI bleeding were studied if the presence of blood or clots obscured the site of bleeding. The potential site of bleeding was initially sprayed with 200 mL water and then with 200 mL 3% hydrogen peroxide mixed with simethicone.

RESULTS

In 6 patients with acute upper GI bleeding, hydrogen peroxide spray resulted in good to excellent visualization of the bleeding source. Hemostasis occurred in 2 patients who were actively bleeding. There were no adverse effects or complications.

CONCLUSIONS

Hydrogen peroxide significantly enhanced clot dissolution and endoscopic visualization in patients with acute upper GI bleeding.

Effect of local injection of botulinum toxin on sphincter of Oddi cyclic motility in dogs

To study effects of intrasphincteric injections of botulinum toxin on the sphincter of Oddi cyclic motility and responses to motilin and cholecystokinin, four conscious dogs with duodenal cannula underwent manometry of the common bile duct, sphincter of Oddi, and duodenum. After baseline recording, each dog had intrasphincteric injections of saline or botulinum toxin. The injections of saline had no effect, whereas botulinum toxin significantly reduced mean basal pressure, amplitude, and motility index of the sphincter of Oddi. These effects took place in four to seven days and reached a maximum in seven to 10 days. The basal pressure returned to the baseline level in 28 weeks, but the amplitude and motility index remained low. The pressure parameters of motilin-induced premature phase III-like activity also decreased, but action of cholecystokinin was not affected. These results indicate that the botulinum toxin injections reduce sphincter of Oddi phasic contractile activity for a prolonged period of time.

Reflux strictures of the esophagus

Gastroesophageal reflux disease (GERD) is the most common cause of esophageal strictures, accounting for approximately 70% of all cases. Reflux strictures of the esophagus are serious complications of GERD and are associated with a high relapse rate. Goals of long-term management include the relief of dysphagia, prevention of stricture recurrence, and avoidance of complications with safe, cost-effective therapy. Despite recent advances in knowledge about GERD, reflux stricture still remains a relatively common and challenging clinical problem.

Primary sclerosing cholangitis: resect, dilate, or transplant?

OBJECTIVE

The current study examines the results of extrahepatic biliary resection, nonoperative endoscopic biliary dilation with or without percutaneous stenting, and liver transplantation in the management of patients with primary sclerosing cholangitis (PSC).

SUMMARY BACKGROUND DATA

Primary sclerosing cholangitis is a progressive inflammatory disease leading to secondary biliary cirrhosis. The most effective management of sclerosing cholangitis before the onset of cirrhosis remains unclear.

METHODS

From 1980 to 1994, 146 patients with PSC were managed with either resection of the extrahepatic bile ducts and long-term transhepatic stenting (50 patients), nonoperative endoscopic biliary dilation with or without percutaneous stenting (54 patients), medical therapy (28 patients), and/or liver transplantation (21 patients).

RESULTS

Procedure-related morbidity and mortality rates were similar between surgically resected and nonoperatively managed patients. In noncirrhotic patients, the serum bilirubin level was significantly (p < 0.05) reduced from preoperative levels (8.3+/-1.5 mg/dL) 1 (1.7+/-0.4 mg/dL) and 3 (2.7+/-0.9 mg/ dL) years after resection, but not after endoscopic or percutaneous management. For noncirrhotic PSC patients, overall 5-year survival (85% vs. 59%) and survival until death or transplantation (82% vs. 46%) were significantly longer (p < 0.05) after resection than after nonoperative dilation with or without stenting. For cirrhotic patients, survival after liver transplantation was longer than after resection or nonoperative dilation with or without stenting. Five patients developed cholangiocarcinoma, including three (6%) of the nonoperatively managed patients but none of the resected patients.

CONCLUSIONS

In carefully selected noncirrhotic patients with PSC, resection and long-term stenting remains a good option. Patients with cirrhosis should undergo liver transplantation.

The role of sphincter of Oddi manometry in the diagnosis and therapy of pancreatic disease

Endoscopic manometry of the sphincter of Oddi (SO) is now an accepted technique in the diagnosis and therapy of biliary disease. Its role in the evaluation of pancreatic sphincter function for pancreatic diseases, however, is evolving. There are now preliminary data to suggest that pancreatic SO manometry may identify a subgroup of patients with pancreatic sphincter dysfunction that may benefit from endoscopic therapy. Further prospective clinical trials are sorely needed to evaluate the response of endoscopic therapy based on pancreatic SO basal pressure or pancreatic ductal pressure.

Recent advances in the treatment of achalasia

Achalasia is a disorder of the esophagus characterized by aperistalsis and failure of the lower esophageal sphincter to relax. This article discusses traditional and new therapies directed against the sphincter muscle. Because limitations of these treatments do exist, alternatives to sphincter destruction are presented.