Targeting Epilepsy Through the Foremen Ovale: How Many Helical Needles are Needed?

Laser ablation of the hippocampus offers medically refractory epilepsy patients an alternative to invasive surgeries. Emerging commercial solutions deliver the ablator through a burr hole in the back of the head. We recently introduced a new access path through the foremen ovale, using a helical needle, which minimizes the amount of healthy brain tissue the needle must pass through on its way to the hippocampus, and also enables the needle to follow the medial axis of the hippocampus more closely. In this paper, we investigate whether helical needles should be designed and fabricated on a patient-specific basis as we had previously proposed, or whether a small collection of pre-defined needle shapes can apply across many patients. We propose a new optimization strategy to determine this needle set using patient data, and investigate the accuracy with which these needles can reach the the medial axis of the hippocampus. We find that three basic tube shapes (mirrored as necessary for left vs. right hippocampi) are all that is required, across 20 patient datasets (obtained from 10 patient CT scans), to reduce worst-case maximum error below 2 mm.

Colorectal neodymium-YAG photoablative therapy. Comparing applications and complications on both sides of the peritoneal reflection.

Laser photoablative therapy has seen wide application in the esophagus, stomach, and rectum. Its use in the supraperitoneal colon has been less extensive because of fear of complications. One hundred fifteen patients who presented during a four-year period and underwent neodymium-YAG laser treatment on both sides of the peritoneal reflection (rectum, 47 patients; colon, 68 patients) were reviewed. The various lesions treated with laser therapy included 32 malignant tumors that presented with bleeding or obstruction, 44 large broad-based villous adenomas, six carcinoid tumors, and 33 patients with arteriovenous malformations or radiation proctitis who presented with acute hemorrhage or chronic blood loss. Overall treatment efficiency was 83% in the rectal group vs 87% in the colonic group. There was no significant difference in complication frequency or severity between the two groups, even though 45% of the colonic lesions were located in the thin-walled cecum. There was no laser-related mortality in this series. Laser photoablative therapy is safe and effective treatment for a wide variety of colorectal lesions. In experienced hands, it can be used on either side of the peritoneal reflection with equal efficiency and no increased risk of complications.

Transpapillary stenting for pancreaticocutaneous fistulas.

Because transpapillary stents have been successfully placed to treat the ductal disruptions associated with pseudocysts, pancreatic ascites and pleural effusions, and pancreaticoenteric fistulas, we reviewed our experience with endoscopically placed prostheses in patients who had persistent pancreaticocutaneous fistulas but an otherwise intact duct. Nine patients who underwent endoscopic transpapillary stent placement for ongoing pancreaticocutaneous fistulas at our institution were retrospectively reviewed. Fistulas were present for a mean (+/-SEM) of 35 +/- 11 days and averaged 225 +/- 55 ml of output daily. Etiology of the fistulas included percutaneous pseudocyst drainage in four patients, pancreatic necrosis in two, complications of pancreatic surgery in two, and perforation of the duct of Santorini at the time of minor sphincterotomy in one. All patients had an otherwise intact duct at the time of endoscopic retrograde cholangiopancreatography. Six patients had transpapillary stents placed that did not bridge the area of leakage and three had prostheses placed across the ductal disruption. Eight of nine fistulas were successfully closed by means of this technique including five within 48 hours. There was one instance of stent migration and one patient developed prosthesis occlusion and an infected pseudocyst, which was treated with stent exchange. Stents were retrieved 10 to 14 days after fistula closure and no patient has had a recurrence at a median follow-up of 3 years. Transpapillary stents appear to effect closure of pancreaticocutaneous fistulas that fail to respond to conventional therapy.

Extracorporeal shock-wave lithotripsy for bile duct calculi.

BACKGROUND: Bile duct calculi (BDC) can be cleared or treated with modern endoscopic techniques in most patients. However, large stones, bile duct strictures, or unusual anatomy may make endoscopic clearance difficult. The purpose of the present study was to determine the efficacy of extracorporeal shock-wave lithotripsy (ESWL) in treating patients with complicated BDC. METHODS: Between 1989 and January 1995, 16 patients with BDC were treated at our institution with ESWL using a Dornier HM-3 lithotropter. The average age of patients was 62 years (range 32 to 88). Endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy and attempted stone extraction (100%), nasobiliary drainage (83%), and biliary stents (6%) were used prior to ESWL. Eleven patients (61 %) had solitary stones, ranging in diameter from 0.5 to 2.6 cm, whereas 7 patients had multiple stones, ranging in diameter from 0.5 to 5.0 cm. The indications for ESWL were stone impaction (56%), stone size (38%), and bile duct stricture (6%). RESULTS: The 16 patients received 27 ESWL treatments (mean = 2101 shock at 21 kV); with 4 patients (22%) requiring multiple treatments. Stone fragmentation was achieved in 94% of patients. All patients had ERCP performed post-ESWL, and only 2 (13%) patients required immediate operations. At discharge, 94% of patients were stone-free. Minor complications (eg, pain, hematuria) were common. With an average follow-up of 3 years, only 1 patient (6%) has required retreatment for BDC. Hepatic transplantation was required in an additional patient. CONCLUSIONS: In this cohort of patients with both major medical comorbidities and/or technical contraindications to standard methods of endoscopic and surgical clearance of BDC, we found that ESWL facilitated stone clearance in 94% of patients with minimal morbidity and no mortality. In our opinion, ESWL should be used more frequently in the treatment of these complex patients.

Endoscopic retrograde cholangiopancreatography after laparoscopic cholecystectomy.

We assessed the use of endoscopic retrograde cholangiopancreatography (ERCP) after laparoscopic cholecystectomy (LC) at our hepatobiliary referral center. This assessment included patients from outside institutions with post-LC problems. Between May 1990 and September 1992, we performed 522 LCs and 1,723 ERCP examinations. There were 78 patients who underwent 143 ERCP examinations after LC, 65% of whom were referred. ERCP findings were categorized as follows: normal results (8%), problems inherent to stone disease (65%), and iatrogenic injury (27%). The types of inherent problems were common bile duct (CBD) stones, pancreatitis, and papillary stenosis/microlithiasis. Within the CBD stone group, 5 of 26 patients also had papillary stenosis, and, within the pancreatitis group, 9 of 11 patients also had papillary stenosis, making papillary stenosis the most frequent observation (55%). Almost all of these patients (96%) required endoscopic papillotomy for successful treatment. The iatrogenic injury group was comprised of 21 patients, 16% of whom had cystic duct leak and 84% of whom had CBD injury. These patients required a variety of endoscopic procedures including endoscopic papillotomy (67%), CBD endoscopic stenting (76%), percutaneous drainage of biloma (29%), and percutaneous transhepatic biliary drainage (24%). Open surgical procedures after endoscopic assessment or treatment were required in only three patients in the iatrogenic group and in none in the inherent group. At this time, long-term follow-up is not possible with regard to biliary stricture. We conclude that the majority of problems after LC are either due to papillary stenosis/microlithiasis with or without CBD stones or to biliary injury. Both can be successfully diagnosed and treated with endoscopic techniques.

Evaluation of endoscopic retrograde cholangiopancreatography and angiography in the diagnosis of pancreatic carcinoma.

A series of 118 patients with suspected pancreatic disease was studied by endoscopic retrograde cholangiopancreatography (ERCP). Angiography was subsequently performed in 30 of these patients. ERCP was 95% accurate in the prospective diagnosis of pancreatic carcinoma. This study suggests that angiography is valuable in determining tumor resectability following ERCP diagnosis of pancreatic carcinoma. Angiography may obviate the need for exploratory laparotomy in patients with unresectable tumors and encourage aggressive treatment of resectable lesions. Patients with a high clinical suspicion of pancreatic disease should have angiography if the ERCP is normal, equivocal, or there is a cannulation failure.

Rapid diagnosis of pancreatic carcinoma.

An algorithmic approach for radiological evaluation of suspected pancreatic carcinoma was applied in more than 200 patients. Outpatient ultrasonography and barium studies of the upper gastrointestinal tract were followed by inpatient endoscopic retrograde cholangiopancreatography, angiography, and percutaneous biopsy. Evaluation took no more than two hospital days and exploratory laparotomy was not needed. Twenty-five patients had carcinoma. The diagnostic accuracy of the algorithm was 96%. Although this method did not increase the diagnosis of resectable tumors, it did result in rapid, accurate diagnosis of pancreatic carcinoma at relatively low cost and with minimum patient discomfort. Hopefully, these results will eventually lead to earlier diagnosis and improved survival.

Endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC) in the evaluation of suspected pancreatic carcinoma: diagnostic limitations and contemporary roles.

The accuracy of ERCP and PTC in the diagnosis of pancreatic carcinoma was evaluated in a series of 376 and 112 patients, respectively. ERCP had a sensitivity of 94% and a specificity of 97%; PTC had a sensitivity of 100% and a specificity of 96%. Prior to the introduction of CT, these highly accurate examinations were the first major diagnostic procedures performed in patients with suspected pancreatic carcinoma. CT has had a significant impact on the role of ERCP and PTC and has replaced them as the initial procedure of choice. The current indications for ERCP and PTC were evaluated in a series of 211 patients with suspected pancreatic disease who were studied initially by CT. ERCP is now used to evaluate patients in whom CT is normal, equivocal, or technically unsatisfactory. PTC is used as a preoperative procedure for precise definition of biliary anatomy or for percutaneous placement of a palliative biliary drainage catheter.

ERCP-guided percutaneous fine-needle pancreatic biopsy.

In patients with a radiologic diagnosis of unresectable pancreatic carcinoma, exploratory laparotomy for tissue diagnosis is no longer required. Histologic confirmation of the diagnosis may be obtained safely and accurately with percutaneous fine-needle aspiration biopsy. Endoscopic retrograde cholangiopancreatography (ERCP) precisely localized the biopsy site for cytologic diagnosis of adenocarcinoma in 13 of 14 patients (93 percent) with pancreatic carcinoma.

Metallic self-expanding stent application in the upper gastrointestinal tract: caveats and concerns.

Ten patients with a variety of upper gastrointestinal tract stenoses precluding conventional prostheses or associated with recurrent occlusions of these prostheses, had an expandable metal Z stent placed. All patients had successful insertion (esophagus, five; biliary, three; afferent loop, one; efferent loop, one), although there was a tendency for the prostheses to delivery distally (gut) or proximally (biliary tree). Despite patency rates for up to 6 months in the esophagus and 1 year in the biliary tree, additional data and design modifications are required before widespread utilization.

Endoscopic approach to pancreatic duct calculi and obstructive pancreatitis.

Twelve patients with chronic pancreatitis and obstructing pancreatic calculi underwent endoscopic retrograde cholangiopancreatography and attempted pancreatic stone extraction. This procedure, utilizing conventional stone baskets and balloons, as well as extracorporeal or laser lithotripsy in a subset, was ultimately successful in 11 of 12 patients. Nine of the 10 patients with relapsing pancreatitis have not had a symptomatic flare at a mean follow-up of 17 months. In contrast, neither of the patients who presented with chronic pain had convincing symptomatic improvement. The authors conclude that endoscopic removal of pancreatic duct calculi deserves further investigation in the treatment of relapsing attacks of chronic pancreatitis.

The absolute configuration of SU 23397: a novel neuroleptic agent.

The absolute configuration of a novel chiral neuroleptic agent SU 23397 (I) was determined by ORD comparison of (+)-5-methoxy dihydro coumarilic acid (VIII), a synthetic precursor of SU 23397 (I), with (+)-dihydro coumarilic acid, whose absolute configuration is known. This assignment was confirmed by oxidative degradation of (+)-5-methoxy dihydro coumarilic acid VIII to D-(+)-malic acid.

Impact of new diagnostic imaging methods on pancreatic angiography.

The results of 100 consecutive pancreatic arteriograms performed in concert with a combination of other diagnostic procedures (gray scale ultrasonography, computed tomography, endoscopic retrograde cholangiopancreatography, percutaneous transhepatic cholangiography) were evaluated to determine the value of angiography in diagnosis and management of patients with known or suspected pancreatic disease. Angiography was found to be valuable for diagnosis in 68% (68/100) of cases and was considered helpful for management in 81% (57/70) of patients with pancreatic neoplasm, pancreatitis, or a nonpancreatic abnormality.

When push comes to shove: a comparison between two methods of percutaneous endoscopic gastrostomy.

Percutaneous endoscopic gastrostomy has supplanted surgical gastrostomy in a number of medical centers. A variety of makeshift or commercially available gastrostomy kits has been used, as have several insertion techniques. Despite widespread use, however, there are conflicting reports regarding the best method of gastrostomy tube insertion. Studying 30 patients, 15 of whom underwent percutaneous endoscopic gastrostomy with the "push" and 15 with the "pull" technique, we found both methods successful, and associated with an acceptable complication rate. In the authors' hands, the "pull" technique was technically easier.

Impact of high-resolution computed tomography of the pancreas on utilization of endoscopic retrograde cholangiopancreatography and angiography.

The impact of computed tomography (CT) on utilization of other diagnostic procedures was studied by comparing the results obtained in two groups of patients: (a) 278 patients studied prior to the availability of CT, and (b) 300 patients studied using CT. CT enabled an accurate diagnosis in 74% of patients without the use of additional examinations. Utilization of CT as the initial imaging procedure resulted in a decrease in the utilization of endoscopic retrograde cholangiopancreatography (ERCP) and angiography by 68% and 54%, respectively. This resulted in a 47% decrease in the overall cost of radiologic diagnosis.

Nd-YAG laser photoablation of sessile villous and tubular adenomas of the colorectum.

Neodymium (Nd)-YAG laser photoablation treatment was used to treat 46 patients with broad-based villous and tubular adenomas of the colon or rectum. These adenomas were distributed throughout the large bowel, with the majority (72%) located above the peritoneal reflection. Patients received an average of 2.1 treatments per adenoma, with 22 patients (48%) requiring only one treatment. Overall treatment success was achieved in 89% of cases (mean follow-up of 12 months), with four patients undergoing continued therapy. Of the patients who received a full course of treatment, only two (4%) were not taken to complete photoablation. Complications were minimal, and 92% of all laser treatments were done on an outpatient basis. Four patients had documented polyp recurrence that was controlled with additional laser treatment. Two patients with malignant polyps who were not surgical candidates were also treated with the laser, with no tumor recurrence seen at 11 and 14 months. Nd-YAG laser photoablation of large colonic polyps offers a safe, efficient, and cost-effective alternative to standard surgical resection.

Endoscopic variceal sclerotherapy as primary treatment for bleeding esophageal varices.

In this study of 75 patients with bleeding esophageal varices we confirm not only the ability of endoscopic variceal sclerotherapy (EVS) to control acute bleeding episodes but to effect variceal obliteration that confers a significant survival advantage, regardless of initial Child's classification. Survival correlates directly with the degree of hepatic dysfunction, although all patients regardless of Child's status have a statistically significant survival advantage when treated until esophageal variceal obliteration is achieved. All patients treated with EVS should be followed for life, but virtually all follow-up can be done on an outpatient basis. Shunt surgery should be reserved for: (a) patients whose acute bleeding cannot be controlled with EVS at the time of index bleed; and (b) patients who rebleed repeatedly or uncontrollably from gastric or duodenal varices. EVS is more cost-effective than other available treatments. It also effectively stabilizes potential candidates for orthotopic liver transplantation. Despite a progressive increase in the admissions for bleeding varices at our institution, the introduction of EVS has been associated with a significant decline in portosystemic shunt therapy. We believe that EVS is now the first-line treatment for all patients with bleeding esophageal varices.

Endoscopic retrograde biliary drainage.

Endoscopic retrograde biliary drainage (ERBD) was completed in 30 of 34 attempts (88.2%). Sixteen patients are alive with functioning stents one to 14 months following insertion of the catheters. Eight patients died with functioning stents two weeks to four months following placement. Six stents were replaced due to sepsis or rising bilirubin one to eight months following initial insertion. The only immediate complication was sepsis, which developed in one patient. Since ERBD circumvents many of the complications associated with percutaneous transhepatic drainage, it has replaced this technique in our institution as the primary non-operative modality for biliary decompression. Percutaneous transhepatic drainage is now reserved for ERBD failures.

Hemobilia following percutaneous liver biopsy.

A patient underwent a routine percutaneous liver biopsy and subsequently developed gastrointestinal hemorrhage, biliary colic, and bilirubinuria suggesting the presence of hemobilia. After a negative arteriogram endoscopic cholangiography was used to confirm the diagnosis.