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K Wendl

Publications and source records attributed to K Wendl.

17 recordsLinked to original sources
PubMed2004

[Intraoperative three-dimensional navigation for pedicle screw placement].

The mobile SIREMOBIL Iso-C(3D) C-arm (Siemens, Erlangen, Germany) is the first device permitting intraoperative, three-dimensional representation of bone structures. A high-resolution, isotropic 3D data cube in the isocenter with sides of approximately 12 cm is calculated simultaneously. The SIREMOBIL Iso-C(3D) is linked to the navigation system. This makes it possible to transfer the generated 3D data directly to the linked navigation system without the need for surgeon-dependent registration. In this prospective clinical trial, we evaluated the accuracy of pedicle screw placement using this device. In 61 patients, a total of 302 pedicle screws were placed. Only in five cases (1.7%) were misplacements of > or =2 mm shown in postoperative control CT. The average fluoroscopy time was 1.28+/-0.56 min, and the average operative duration was 103.26+/-23.3 min. There were no postoperative neurological complications in any of the 30 patients. From these data, we conclude that Iso-C(3D) navigation is a very accurate method for the placement of pedicle screws.

Adolescent↗
PubMed2003

[CT-free image guided acetabulum navigation in clinical routine].

After experimental and preclinical evaluation (HAP Paul Award 2001) of the CT-free image-guided surgical navigation system for acetabular cup placement (SurgiGATE C-arm cup" by Medivision, Switzerland), the system was introduced into clinical routine. The computation of the angular orientation of the cup is based on reference coordinates from the anterior pelvic plane concept. A hybrid strategy for pelvic landmark acquisition has been introduced involving percutaneous pointer-based digitization with the noninvasive biplanar landmark reconstruction using multiple registered fluoroscopy images. From January 2001 to December 2002, a total of 256 consecutive patients with primary osteoarthrosis (mean age 69 years, 161 male, 95 female, 132 left, and 124 right hip joints) were operated on with the hybrid CT-free navigation system. During each operation the angular orientation of the inserted implant was recorded. To determine the placement accuracy of the acetabular components, 50 consecutive patients underwent a CT scan 7-10 days postoperatively to analyze the cup position related to the anterior pelvic plane. This was all done blinded by the same investigator with the planning software of the CT-based navigation system of Medivision. There was no significant learning curve observed for the use of the system. The mean value for postoperative inclination was 43 degrees (SD 3.0, range: 37 degrees -49 degrees ) and for anteversion 19 degrees (SD 3.9, range: 10 degrees -28 degrees ). The resulting system accuracy, i.e., the difference between intraoperatively calculated cup orientation and postoperatively measured implant position showed a mean error of 1.5 degrees for the inclination (maximum 5 degrees, SD 1.1) and 2.4 degrees for the anteversion (maximum 6 degrees, SD 1.3). An accuracy of better than 5 degrees inclination and 6 degrees anteversion was achieved under clinical conditions, which implies that there is no significant difference in performance from the established CT-based navigation methods. Image-guided CT-free cup navigation provides a reliable solution for future THA.

Acetabulum↗
PubMed2003

[Iso-C(3D0-assisted) navigated implantation of pedicle screws in thoracic lumbar vertebrae].

The mobile Siremobil Iso-C(3D) C-arm (Siemens AG, Medical Solutions, Erlangen) is the first device that permits the intraoperative three-dimensional (3D) representation of bone structures. A high-resolution isotropic 3D data cube in the isocenter with an edge length of approximately 12 cm is calculated simultaneously. The Siremobil Iso-C(3D) is linked to navigation with the integrated NaviLink interface (Siemens AG, Medical Solutions, Erlangen). This makes it possible to transfer the generated 3D data directly to the linked navigation system Surgigate (Medivision, Oberndorf, Switzerland). In this prospective clinical trial we evaluated the accuracy of pedicle screw placement using the Siremobil Iso-C(3D) C-arm. The results were compared to the conventional approach and other computer-assisted procedures (CT-based navigation, C-arm-based 2D navigation) in historical control groups. A total of 141 pedicle screws were placed in 30 patients (70 thoracic spine, 71 lumbar spine). Only in one single case was misplacement shown in the postoperative control CT scan (0.71%), the lowest rate of incorrect placements of all techniques. Also the lowest average fluoroscopy time (1.28+/-0.56 min) was achieved during the placement of pedicle screws on the spine with Iso-C(3D) navigation at a comparable average OR duration (103.26+/-23.3 min). There were no postoperative neurological complications in all 30 patients. From these data we conclude that Iso-C(3D) navigation of pedicle screws is a very accurate method in the correct placement of pedicle screws.

Bone Screws↗
PubMed2001

Personal observations, opinions, and approaches to cancer of the pancreas and the periampullary area.

This article reviews the diagnosis, staging, surgical, and adjuvant treatment of pancreatic and periampullary cancer based on personal experience covering 25 years. In spite of remarkable progress, especially in regard to staging and surgical treatment, the authors conclude that with the modalities currently available, timely diagnosis and definitive cure of this particular cancer is rare.

Adult↗
PubMed2001

Rare indications for a Kausch-Whipple procedure.

OBJECTIVES: To find out whether the Kausch-Whipple operation is adequate for the cure of rare tumours of the pancreatic head. DESIGN: Retrospective study. SETTING: University hospital, Germany. PATIENTS: Of 640 patients who had Kausch-Whipple procedures between 1972 and 1998 we found 42 (6.6%) who were operated on for rare tumours of the pancreatic head. RESULTS: Among these 42 patients 12 had functioning and non-functioning endocrine tumours, 11 had adenomas that were not locally resectable, 6 had leiomyosarcomas or oncocytomas, 4 had cystadenocarcinomas, 3 had acinar cell carcinomas, 2 had primary lymphomas, and 3 had metastases to the pancreatic head. Operative treatment (such as extended resection), postoperative course, and survival time after operation varied. Patients with adenomas had the most favourable mean survival time of 106.5 months. Among patients with cancer, those with endocrine malignancies had the best outcome with a mean survival duration of 58.3 months.

Adult↗
PubMed1999

Nerve irritation after laparoscopic hernia repair.

BACKGROUND: Between October 1992 and May 1996, 893 hernia repairs were performed at the Surgical Clinic in Mannheim: 448 (50%) using laparoscopy (TAPP-method) and 445 (50%) using the conventional anterior approach (Shouldice). MATERIALS AND METHODS: For this study, 723 (81%) of these repairs were followed up in a prospective trial of postoperative nerve irritations. RESULTS: The rate of nerve entrapment in the laparoscopic group was 4.2% (n = 19), and in the group that underwent conventional surgery 1.8% (n = 8). The genitofemoral nerve was affected with particularly high frequency (2%), and the ilioinguinal nerve and lateral cutaneous nerve of the thigh (LCNT) each was affected in 1.1% of the cases. CONCLUSIONS: Reduction in the number of clips used and careful attention to the anatomic nerve course during preparation and placement of mesh led to a significant reduction in the occurrence of nerve irritations. In the last 100 patients who underwent laparoscopic hernia repair, only one nerve lesion was seen.

Female↗
PubMed1999

Treatment of endoscopic esophageal perforation.

BACKGROUND: The increasing usage of flexible endoscopy leads to a higher incidence of esophageal perforations, whose treatment strategies (conservative or operative) still are discussed controversially. We present our experiences and therapy concepts in relation to 75 iatrogenic esophageal perforations. PATIENTS: Between 1983 and 1997, 75 patients were treated for endoscopic perforation of the esophagus. The gender distribution was 31 females (41.3%) and 44 males (58.7%), with a mean age of 64.4 years (range 2-90 years). RESULTS: Therapeutic endoscopy was the most common cause of perforation (73 of 75 patients; 97.3%). Diagnostic endoscopy caused perforation in 2 patients (2.7%). The perforation was located in the cervical part of the esophagus in 7 patients (9.3%), the intrathoracic part in 25 patients (33.3%), and the abdominal part in 43 patients (57.3%). In this study population, 25 patients (33.3%) were treated surgically, and 50 patients (66.7%) conservatively. The overall in-hospital mortality rate was 14 of 75 patients (18.7%). In the surgically treated group the rate was 6 of 25 patients (24%) and in the conservative group 8 of 50 patients (16%). CONCLUSIONS: The decision of a treatment strategy depends on different factors such as the location and extent of the injury, the time interval between perforation and treatment onset, the preexisting diseases, and the patient's general condition. In view of these factors, an individual therapy concept should be determined for every patient.

Adolescent↗
PubMed1999

[The value of magnetic resonance tomography (MRT), magnetic resonance cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis of pancreatic tumors].

PURPOSE: To prospectively evaluate the role of MRI including MR cholangiopancreatography (MRCP) compared to endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis of pancreatic cancer. MATERIAL AND METHODS: ERCP and MRI including MRCP were performed in 52 patients with suspected pancreatic cancer. MRCP was obtained using a single-shot RARE technique. The results of axial images and MRCP were compared to concurrently performed ERCP examinations. The standards of reference were the surgical and pathological findings, respectively. Image quality of MRCP was assessed using a three-step-score (1 = good, 2 = fair, 3 = nondiagnostic). RESULTS: In 88% of the cases the MRCP was of good quality. Only in 4% was MRCP non-diagnostic. The combination of MRI and MRCP showed an overall accuracy of 88%, whereas the overall accuracies of MRCP alone and ERCP were 80%, and 85%, respectively. The positive predictive values of MRI/MRCP, MRCP alone, and ERCP were 91%, 85%, and 88%, respectively. CONCLUSION: For the detection of pancreatic cancer MRI including MRCP is comparable to ERCP and can be regarded as the method of choice in patients with suspected pancreatic cancer. ERCP is the procedure of choice in patients with contraindications to MRI and in patients in whom additional therapeutic procedures are performed.

Adenocarcinoma↗
PubMed1999

[Combined use of MRI and MR cholangiopancreatography and contrast enhanced dual phase 3-D MR angiography in diagnosis of pancreatic tumors: initial clinical results].

PURPOSE: To evaluate the accuracy of a non-invasive "all-in-one" staging MR method in patients with pancreatic tumors. MATERIAL AND METHODS: 46 patients were prospectively evaluated by a combined MR imaging protocol including breath-hold T1- and T2-weighted pulse sequence, MRCP using a breath-hold 2D-RARE sequence, and breath-hold gadolinium-enhanced dual-phase 3D-MR angiography. RESULTS: All pancreatic tumors were detected by the combination of cross-sectional imaging and MRCP. In spite of the use of MRCP, definitive differentiation between pancreatic carcinoma and chronic pancreatitis was not possible in 3 (6.5%) out of 46 cases. High quality 3D-MR angiograms were obtained in 43 (93.5%) cases. In 6 (13%) patients 3D-MRA showed an aberrant right hepatic artery. The overall accuracy of MRI in assessing extrapancreatic tumor spread, lymph node metastases, liver metastases, and vascular involvement was 95.7%, 80.4%, 93.5%, and 89.1%, respectively. CONCLUSION: Due to its high accuracy, the "all-in-one" MR protocol may become the most important modality after clinical examination and ultrasound in the diagnostic work-up for most patients with suspicion of pancreatic tumors.

Arteries↗
PubMed1999

HLA-DR expression in acute pancreatitis.

OBJECTIVE: To investigate the role of the monocyte/macrophage system in acute pancreatitis DESIGN: Prospective clinical study SETTING: University clinic, Germany SUBJECT: 37 consecutive patients who presented with acute pancreatitis. MAIN OUTCOME MEASURE: Correlation between function of monocytes measured by HLA-DR expression and outcome RESULTS: Patients were divided into three groups according to outcome: those with severe pancreatitis who died (n = 10), those with severe pancreatitis who survived (n = 15), and those with mild pancreatitis who survived (n = 12). There was a clear and significant difference between those with severe and those with mild disease. HLA-DR expression was initially depressed in both groups, but after the third day of treatment it started to recover significantly in those with mild disease (p < 0.05). The difference was also significant from day 7 onwards between those with severe disease who died and those with severe disease who survived (p < 0.05). CONCLUSION: Monocyte function as measured by HLA-DR expression (CD14+DR+) is reduced in patients with acute pancreatitis and does not recover in patients who are going to die (median < 20 relative antigen density units; RU).

Adult↗
PubMed1998

[Large Brunner adenoma in the duodenal bulb--a case report].

Benign, proliferative changes of the Brunner's gland are very rare and account for about 10% of duodenal bulb neoplasias. The authors present a case of Brunner's gland adenoma of unusual dimensions (12 x 5 x 2.5 cm). The patient presented with vague epigastric discomfort as isolated symptoms. In this case we performed surgical treatment, including a duodenotomy and polypectomy. Because they are localized in the submucosa small, superficial endoscopic biopsies may fail to confirm the diagnosis. Malignancy seems to occur only very rarely, with only 14 cases reported in the literature. As the majority of Brunner's adenomas are quite small, endoscopic polypectomy will confirm the diagnosis and cure the condition in most cases. Large symptomatic adenomas may require surgical resection.

Adenoma↗
PubMed1998

[Pancreatic carcinoma--conclusions and prospects].

Whereas no progress has been made in the diagnosis of early tumors, the staging of pancreatic cancer has improved, mainly through the introduction of ultrafast MRI, resulting in a higher resection rate. The early results of standard pancreatectomy are now excellent (operative mortality < 2.5%). The late results after R0 resections are improving (> 30% 5-year survival), but they are poor overall. So far, extended surgical techniques have not brought any improvement here. Unfortunately, so far adjuvant radiochemotherapy has not proved effective in a recent randomized controlled trial. Molecular and genetic research has deepened our understanding of the cancerogenesis of pancreatic cancer without leading to clinical consequences so far.

Aged↗
PubMed1998

[Magnetic resonance tomography in diagnosis of vascular infiltration in malignant pancreas tumors].

This study was undertaken to evaluate the accuracy of magnetic resonance angiography (MRA) in assessing venous or arterial infiltration in pancreatic cancer. In 90 patients MRA showed a sensitivity of 81.1%, a specificity of 90.2% and an accuracy of 85.9% in predicting venous infiltration and a sensitivity of 81.8%, a specificity of 90.7% and an accuracy of 88.1% in predicting arterial infiltration. From these data we conclude that MRA is an accurate method for detecting vascular infiltration in pancreatic cancer.

Arteries↗
PubMed1997

Ultrafast magnetic resonance imaging improves the staging of pancreatic tumors.

OBJECTIVE: This prospective study was undertaken to evaluate the accuracy of a noninvasive "all-in-one" staging method in predicting surgical resectability in patients with pancreatic or periampullary tumors. SUMMARY BACKGROUND DATA: Despite progress in imaging techniques, accurate staging and correct prediction of resectability remains one of the chief problems in the management of pancreatic tumors. Staging algorithms designed to separate operable from inoperable patients to save the latter an unnecessary laparotomy are becoming increasingly complex, expensive, time-consuming, invasive, and not without risks for the patient. METHODS: Between August 1996 and February 1997, 58 consecutive patients referred for operation of a pancreatic or periampullary tumor were examined clinically and by 5 staging methods: 1) percutaneous ultrasonography (US); 2) ultrafast magnetic resonance imaging (UMRI); 3) dual-phase helical computed tomography (CT); 4) selective visceral angiography; and 5) endoscopic cholangiopancreatography (ERCP). The assessment of resectability by each procedure was verified by surgical exploration and histologic examination. RESULTS: The study comprised 40 male and 18 female patients with a median age of 63 years. Thirty-five lesions were located in the pancreatic head (60%), 11 in the body (19%), and 1 in the tail of the gland (2%); there were 9 tumors of the ampulla (16%) and 2 of the distal common duct (3%). All five staging methods were completed in 36 patients. For reasons ranging from metallic implants to contrast medium allergy or because investigations already had been performed elsewhere, US was completed in 57 (98%), UMRI in 54 (93%), CT in 49 (84%), angiography in 48 (83%), and ERCP in 49 (84%) of these 58 patients. Signs of unresectability found were vascular involvement in 22 (38%), extrapancreatic tumor spread in 16 (26%), liver metastases in 10 (17%), lymph node involvement in 6 (10%), and peritoneal nodules in only 2 patients (3%). These findings were collated with those of surgical exploration in 47 patients (81 %) and percutaneous biopsy in 5 (9%); such invasive verification was deemed unnecessary and therefore unethical in 6 clearly inoperable patients (10%). In assessing the four main signs of unresectability (extrapancreatic tumor spread, liver metastases, lymph node involvement, and vascular invasion), the overall accuracy of UMRI was 95.7%, 93.5%, 80.4%, as compared to 85.1%, 87.2%, 76.6% for US and 74.4%, 87.2%, 69.2% for CT. In assessing vascular invasion, the sensitivity, specificity, and overall accuracy of angiography were 42.9%, 100%, and 68.8%, respectively. There were 3 complications (12.5%) after 24 resections, 5 in 17 palliative procedures, and none after 6 explorations only. The hospital stay was 14 days after resection, 13 after palliative bypass, and 6 after exploration alone. There was no operative or hospital mortality in these 58 cases. CONCLUSIONS: Although it is by no means 100% accurate, UMRI is equal or even superior to all other staging methods. It probably will replace most of these, because it provides an "all-in-one" investigation avoiding endoscopy, vascular cannulation, allergic reactions, and x-radiation. But because even UMRI is not perfect, the final verdict on resectability of a tumor still will depend on surgical exploration in some cases.

Adult↗