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Biomedical subjects

Stefan Seewald

Publications and source records attributed to Stefan Seewald.

18 recordsLinked to original sources
PubMed2006

Use of modified multiband ligator facilitates circumferential EMR in Barrett's esophagus (with video).

BACKGROUND: Various techniques are available for EMR in the upper- and lower-GI tract. For early cancers of the esophagus, the "suck and cut" technique, which uses a transparent cap or variceal band ligator, is the most commonly practiced method. To facilitate multiple or circumferential EMR, a modified multiband variceal ligator (MBL) is introduced, which allows sequential banding and snare resection without the need to withdraw the endoscope. OBJECTIVE: To study the feasibility of modified MBL device in facilitating circumferential EMR of Barrett's esophagus (BE) that contains high-grade intraepithelial neoplasia (HGIN) and/or intramucosal cancer (IMC). DESIGN: To enable band delivery with a snare inserted in the therapeutic endoscope, the threading channel of the cranking device is enlarged from 2 to 3.2 mm. The 6-shooter MBL was used. PATIENTS: Ten consecutive patients (all men; median age, 62 years; range 43-82 years) with BE were treated. IMC and HGIN were found in 8 and 2 patients, respectively. INTERVENTIONS: EMR was performed with pure coagulating current when using a 1.5 x 2.5-cm mini hexagonal polypectomy snare. No submucosal saline solution injection was performed before resection. RESULTS: In 5 of 10 patients with circumferential BE of 2 to 9 cm in length (median, 4 cm), complete circumferential EMR was performed in 1 session by using 3 to 18 bands (median, 6). Four patients with 3- to 10-cm (median, 4 cm) long segment BE required 2 to 5 sessions (median, 3) with a total of 5 to 42 bands (median, 12). Another patient with multifocal HGIN and/or IMC in 24 of a total of 49 specimens was finally recommended for surgery because of technical difficulties caused by mural thickening after 4 sessions. No serious procedure-related complications were observed, except for 2 minor bleedings, which were controlled endoscopically. Seven patients developed strictures after circumferential EMR. All patients except 1 were successfully managed by weekly bougienage after a median of 5 sessions (range 3-11). Deep-wall tears developed in 1 patient during the fourth bougienage session, for which limited distal esophageal resection was performed with an uneventful outcome. CONCLUSIONS: The novel technique of MBL-EMR described here facilitated and simplified circumferential removal of BE that contained HGIN and/or IMC. However, the method is associated with a very high stricture rate if circumferential EMR is performed in a single session. Complete removal of BE should be achieved by repeated partial EMR. Long-term follow-up is needed to observe for late recurrence and to determine the clinical impact of this method.

Adult↗
PubMed2006

One-step, simultaneous double-wire technique facilitates pancreatic pseudocyst and abscess drainage (with videos).

BACKGROUND: EUS-guided pancreatic pseudocyst and abscess drainage ideally requires the insertion of both a transmural stent and nasocystic catheter to ensure continuous irrigation and effective drainage. Sequential stent and nasocystic catheter insertion may be time consuming because of the difficulty in recannulating the pseudocyst after the initial stent placement. OBJECTIVE: Our purpose was to describe a novel one-step simultaneous double-wire technique that facilitates effective pancreatic pseudocyst and abscess drainage. DESIGN: To solve the problem of recannulating the pseudocyst cavity after the initial transmural stent placement, we developed a prototype 3-layer puncture kit that allows the simultaneous insertion of 2 guidewires at the initial puncture in one step. This puncture kit consists of a 22-gauge needle used for FNA, a 6F inner polytetrafluoroethylene (Teflon) catheter, and an outer 8.5F Teflon catheter. SETTING: Tertiary referral center. PATIENTS: Eight consecutive patients were treated. INTERVENTIONS: With use of a therapeutic linear echoendoscope and the assembled kit with the needle protruding out distally, the pseudocyst cavity was punctured by using electrocautery. The needle and the inner catheter were then withdrawn, leaving the outer catheter within the cavity. The size of this outer catheter permitted the simultaneous insertion of two 0.035-inch guidewires. Sequential insertion of a transmural stent and nasocystic catheter was then performed without a need for recannulation of the pseudocyst or abscess cavity. MAIN OUTCOME MEASUREMENTS: Successful endoscopic drainage. RESULTS: All patients were successfully treated without complications. Mean procedural time was 32.5 minutes (range 25-45 minutes). CONCLUSIONS: With this novel technique, establishing an irrigation system for the treatment of pancreatic pseudocysts and abscesses becomes easier, faster, and safer.

Abscess↗
PubMed2006

Long-term follow-up in small duct chronic pancreatitis: A plea for extended drainage by "V-shaped excision" of the anterior aspect of the pancreas.

BACKGROUND: A pancreatic duct diameter (PDD) ranging from 4 to 5 mm is regarded as "normal." The "large duct" form of chronic pancreatitis (CP) with a PDD >7 mm is considered a classic indication for drainage procedures. In contrast, in patients with so-called "small duct chronic pancreatitis" (SDP) with a PDD <3 mm extended resectional procedures and even, in terms of an "ultima ratio," total pancreatectomy are suggested. METHODS: Between 1992 and 2004, a total of 644 patients were operated on for CP. Forty-one prospectively evaluated patients with SDP underwent a new surgical technique aiming at drainage of the entire major PD (longitudinal "V-shaped excision" of the anterior aspect of the pancreas). Preoperative workup for imaging ductal anatomy included ERCP/MRCP, visualizing the PD throughout the entire gland. The interval between symptoms and therapeutic intervention varied from 12 to 120 months. Median follow-up was 83 months (range, 39-117 months). A pain score as well as a multidimensional psychometric quality-of-life questionnaire was used. RESULTS: Hospital mortality was 0%. The perioperative (30 days) morbidity was 19.6%. Postoperative, radiologic imaging showed an excellent drainage of the entire gland and the PD in all but 1 patient. Global quality-of-life index increased in median by 54% (range, 37.5%-80%). Median pain score decreased by 95%. Twenty-seven patients (73%) had complete pain relief. Sixteen patients (43%) developed diabetes, while the exocrine pancreatic function was well preserved in 29 patients (78%). CONCLUSION: "V-shaped excision" of the anterior aspect of the pancreas is a secure and effective approach for SDP, achieving significant improvement in quality of life and pain relief, hereby sparing patients from unnecessary, extended resectional procedures. The deterioration of exocrine and endocrine pancreatic functions is comparable with that observed during the natural course of the disease.

Adult↗
PubMed2005

Endoscopic resection of benign tumors of the duodenal papilla without and with intraductal growth.

BACKGROUND: Endoscopic papillectomy of benign papillary tumor is still not widely practiced. Intraductal growth has been considered a contraindication for endoscopic therapy. This prospective study evaluates endoscopic papillectomy for treatment of benign papillary tumors without and with intraductal growth. METHODS: Monofilament snare and monopolar electrocoagulation were used for papillectomy. A 7F stent was placed in the pancreatic duct. Patients with distal intraductal growth underwent sphincterotomy and endoscopic resection after exclusion of more proximal growth. RESULTS: Between February 1985 and April 2004, 106 patients (109 lesions), 68 women, 38 men, median age 68 years (range 29-88 years) were included. Median tumor size was 2 cm (range 0.5-6 cm) with one session (range 1-8) required for removal. Nine patients had invasive carcinoma (8%). Surgery for incomplete removal or recurrence was performed in 12% of 75 patients without and 37% of 31 patients with intraductal growth (p < 0.01), respectively. Fifteen patients had recurrence (15%); but, only 4 required surgery. Endoscopic resection was curative (median follow-up, 43 months) in 83% without and 46% with intraductal growth (p < 0.001). CONCLUSIONS: Endoscopic papillectomy is safe and effective, and may be feasible in cases of intraductal growth. Surveillance and, if required, re-treatment are mandatory because of the risk of recurrence.

Adult↗
PubMed2005

Aggressive endoscopic therapy for pancreatic necrosis and pancreatic abscess: a new safe and effective treatment algorithm (videos).

BACKGROUND: Pancreatic necrosis and pancreatic abscess are severe complications of acute pancreatitis. Surgery is associated with significant morbidity and mortality in these critically ill patients. Endoscopic therapy has the potential to offer a safer and more effective alternative treatment modality. However, its role needs to be further investigated. METHODS: This is a retrospective study of the outcome of consecutive patients with pancreatic necrosis and pancreatic abscess, all unfit to undergo surgery, who underwent a new aggressive endoscopic approach. The treatment includes (1) synchronous EUS-guided multiple transmural and/or transpapillary drainage procedures followed by balloon dilation of the cystogastrostoma or cystoduodenostoma, (2) daily endoscopic necrosectomy and saline solution lavage, and (3) sealing of pancreatic fistula by N-butyl-2-cyanoacrylate. RESULTS: Pancreatic necrosis and pancreatic abscesses were successfully drained in 13 patients, thus avoiding emergency surgery as an initial treatment. Surgery was completely avoided in 9 patients over a median follow-up of 8.3 months (range 3-81 months). Surgery was combined with endoscopic therapy in one patient because of abscess extension into the right paracolic gutter, which was not manageable by endoscopic drainage. Because of the "disconnected-duct syndrome," two patients later developed recurrent pseudocysts and underwent elective surgery. Complications included minor bleeding after balloon dilation and necrosectomy in 4 cases, which were self limiting or controlled endoscopically. CONCLUSIONS: This aggressive endoscopic approach shows promising results. It expands the potential for endoscopic treatment in patients with pancreatic necrosis and/or pancreatic abscess.

Abscess↗
PubMed2004

Endoscopic sealing of pancreatic fistula by using N-butyl-2-cyanoacrylate.

BACKGROUND: The treatment of pancreatic fistula can be difficult. A novel endoscopic approach to sealing pancreatic fistulas by using N-butyl-2-cyanoacrylate is described. METHODS: Twelve patients with pancreatic fistulas underwent endoscopic injection of N-butyl-2-cyanoacrylate into the fistulous tract, in addition to endoscopic drainage. RESULTS: Fistulas were closed successfully in 8 of 12 patients. A single treatment session was successful in 7 patients; a second session was required in one patient. In two patients, closure was temporary, and, in one patient, the treatment failed. One patient died 24 hours after treatment. He developed a pulmonary thromboembolism from a left popliteal vein thrombosis and died from complications of surgical thromboembolectomy. At autopsy, a pulmonary embolus was found, but there was no evidence of N-butyl-2-cyanoacrylate in the lungs. No procedure-related complication occurred over a median follow-up of 20.7 months (range 9-51 months). CONCLUSIONS: In this preliminary study, occlusion of pancreatic fistulas by using N-butyl-2-cyanoacrylate glue was safe and effective, and obviated the need for surgery in a substantial proportion of patients. Further studies of the use of N-butyl-2-cyanoacrylate for closure of pancreatic fistula are warranted.

Adult↗
PubMed2004

EUS-guided FNA of the left adrenal gland in patients with thoracic or GI malignancies.

BACKGROUND: The diagnostic yield and safety of trans-gastric EUS-guided FNA of the left adrenal gland are not well defined. METHODS: All patients with an enlarged left adrenal gland on abdominal imaging and known or suspected malignancy referred to two EUS centers over a 3-year period were included in this study. EUS-guided FNA was performed on an outpatient basis by one of 4 experienced endosonographers. RESULTS: Thirty-one consecutive patients (21 men, 10 women; mean age 64.8 years) were evaluated. Tissue adequate for interpretation was obtained in all patients; no attempt to obtain tissue was unsuccessful. The median number of needle passes was 4.5 (range 1-8). No immediate complications were encountered. EUS-guided FNA confirmed malignant left adrenal involvement in 42% (13/31) of the patients. Patients with malignant left adrenal masses were more likely to have known cancer at another site (OR 12.0: 95% CI[1.6, 87.9]). Patients with benign masses were more likely to have preservation of the normal sonographic appearance of the adrenal gland ("seagull" configuration) compared with those with malignant masses (OR 9.8: 95% CI[1.9, 51.0]). The accuracy of EUS imaging based on size (> or =3 cm) alone was 81%: 95% CI[63, 93]). Of the patients with malignant adrenal masses, 85% (11/13) died or their clinical condition deteriorated during follow-up, while 15% (2/13) were being treated and were stable clinically. CONCLUSIONS: EUS-guided FNA of the left adrenal gland is a minimally invasive, safe, and highly accurate method that confirms or excludes malignant adrenal involvement in patients with thoracic or GI malignancies.

Adrenal Gland Neoplasms↗
PubMed2004

Regulation of mitogen-activated protein kinase cascades by low density lipoprotein and lysophosphatidic acid.

Aim of the present study was to elucidate the regulation of the mitogen activated protein (MAP) kinase cascades as well as the cross-talk between the various MAP kinase isoforms (ERK1/2, SAPK and p38) after stimulation of vascular smooth muscle cells (VSMC) with low density lipoprotein (LDL), 100 microg/ml or lysophosphatidic acid (LPA), 5 microg/ml. Furthermore, the role of the intracellular free Ca(2+) concentration ([Ca(2+)](i)) on the activation of the MAP kinase isoforms as well as on the protein expression of MAP kinase phosphatase (MKP)-1 was investigated. The methods used were Western blot analysis, immunoprecipitation and LDL isolation. Involvement of G(i)-proteins on LDL- and LPA-induced activation of the MAP kinase isoforms was examined by treatment of VSMC with pertussis toxin (PTX),100 ng/ml. LDL as well as LPA induced an activation of SAPK and p38 MAP kinase in a PTX-sensitive manner. The ERK1/2, SAPK and p38 MAP kinase activation was a Ca(2+)-dependent process, most likely regulated through modulation of MKP-1 protein expression. Inhibition of ERK1/2 by PD 98059 completely abolished LDL- and LPA-induced activation of SAPK, whereas the activation of p38 MAP kinase was not affected. We conclude, that [Ca(2+)](i) regulates the PTX-sensitive LDL- and LPA-induced stimulation of the MAP kinase cascades, probably via inhibition of the MKP-1 protein expression.

Animals↗
PubMed2003

Circumferential EMR and complete removal of Barrett's epithelium: a new approach to management of Barrett's esophagus containing high-grade intraepithelial neoplasia and intramucosal carcinoma.

BACKGROUND: There is no study of circumferential EMR in patients with Barrett's esophagus containing early stage malignant lesions. This study investigated the effectiveness and safety of circumferential EMR by using a simple snare technique without cap. METHOD: Patients with Barrett's esophagus containing multifocal high-grade intraepithelial neoplasia or intramucosal cancer, and patients with endoscopically nonidentifiable early stage malignant mucosal changes incidentally detected in random biopsy specimens were included in the study. A 30 x 50-mm polypectomy snare made of monofilament 0.4-mm steel wire was used without any additional device or submucosal injection. RESULTS: Twelve patients (10 men, 2 women; median age 63.5 years, range 43-88 years) underwent circumferential EMR; 5 had multifocal lesions, and 7 had no visible lesions. Segments of Barrett's epithelium were circumferential (median length 5 cm) and completely removed. The median number of EMR sessions was 2.5. The median number of snare resections per EMR session was 5. The medial total area of mucosa in resected specimens per session was 3.8 cm(2). Two patients developed strictures that were successfully treated by bougienage. Minor bleeding occurred during 4 of 31 EMR sessions. During a median follow-up of 9 months, no recurrence of Barrett's esophagus or malignancy was observed. CONCLUSIONS: Circumferential EMR with a simple snare technique is feasible, safe, and effective for complete removal of Barrett's epithelium with early stage malignant changes.

Adult↗
PubMed2002

Advances in interventional gastrointestinal endoscopy in colon and rectum.

BACKGROUND: Instrumental and procedural advances particularly in the therapeutic field have been achieved. REVIEW: Endoscopes with larger working channel, additional jet-channel, or variable stiffness allow more sophisticated interventional procedures. Higher resolution in endoscopic image quality helps to identify early lesions that can be treated endoscopically at this stage. Polypectomy and mucosectomy are no longer limited by the size of the lesion. Piecemeal technique is established, and a retrieval net is available for collecting all pieces obviating repeated introductions of the endoscope. In addition to snare polypectomy and mucosectomy, laparoscopy-assisted polypectomy and full-thickness resection are discussed. Self-expandable metal stents are used to decompress malignant colonic obstruction allowing for either preoperative bowel preparation and elective surgery or for noninvasive palliation. Argon plasma coagulation is an inexpensive and effective method for the treatment of bleeding from radiation proctitis.

Colon↗
PubMed2002

A new radial mechanical puncture echoendoscope: prospective comparison with standard linear and radial echoendoscopes in assessment of focal pancreatic lesions.

BACKGROUND: A new mechanical puncture-echoendoscope was evaluated by comparing it with conventional linear and radial echoendoscopes. The new instrument has a 300 degrees image field parallel to the axis of the echoendoscope, which could potentially improve accuracy and facilitate assessment of suspected pancreatic lesions before needle puncture. METHODS: Twenty consecutive patients with suspected pancreatic lesions were evaluated endosonographically, including fine needle aspiration (FNA). The initial assessment was performed by random selection of either the new instrument or the standard linear echoendoscope. After completing the assessment including FNA, the procedure with FNA was repeated with the other puncture echoendoscope. The findings with these 2 instruments were compared to those with the conventional radial scanning echoendoscope. RESULTS: FNA was performed in 17 patients with pancreatic head lesions. In 3 patients without a visible pancreatic mass lymph, nodes greater than 10 mm in diameter were aspirated. The ability to image the needle, number of punctures, and material obtained were comparable for both puncture echoendoscopes. There were no significant differences with regard to time required for FNA with both puncture echoendoscopes or in the assessment of surrounding structures with all 3 instruments. The results of cytopathologic evaluation of material obtained by FNA were similar in 15 cases. The new instrument could not be passed into the esophagus in 1 patient because of an esophageal stricture. CONCLUSIONS: The performance of the new mechanical puncture echoendoscope was satisfactory for assessment and FNA of pancreatic lesions. The additional use of the conventional radial scanning echoendoscope provided no advantage with regard to any parameter assessed.

Adult↗
PubMed2002

Endoscopic treatment of biliary leakage with n-butyl-2 cyanoacrylate.

BACKGROUND: Biliary leakage is a problematic complication of hepatobiliary surgery. A novel alternative method is described that can obviate the need for reoperation for refractory biliary fistula. METHODS: Nine patients with large biliary leaks unresponsive to endoscopic drainage underwent N-butyl-2-cyanoacrylate glue occlusion at ERCP. RESULTS: In 7 patients, occlusion was successful with prompt control of the fistula in a single session, averting reoperation. In 1 patient there was a partial response and in another the treatment was unsuccessful. No procedure-related complication occurred over a median follow-up of 35 months (range: 1.6-160 months). CONCLUSION: N-butyl-2-cyanoacrylate glue occlusion is a safe and effective endoscopic method for control of refractory bile leaks that eliminates the need for surgical reintervention.

Adolescent↗