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Biomedical subjects

M K Walz

Publications and source records attributed to M K Walz.

At least 55 records · Page 3Linked to original sources
PubMed1998

Percutaneous dilatational tracheostomy--early results and long-term outcome of 326 critically ill patients.

OBJECTIVE: To analyze perioperative and postoperative complications and long-term sequelae following percutaneous dilatational tracheostomy (PDT). DESIGN: A prospective clinical study of patients undergoing PDT. SETTING: Seven intensive care units at a University hospital PATIENTS: 326 intensive care patients (202 male, 124 female; age: 11-95 years) with indications for tracheostomy. INTERVENTIONS: Using tracheoscopic guidance, 337 PDTs were performed according to Ciaglias' method. In 106 decannulated patients, tracheal narrowing was assessed by plain tracheal radiography. RESULTS: Two procedure-related deaths were seen (0.6%). Perioperative and postoperative complications occurred with 9.5% of the PDTs. One of 106 patients, who were followed-up for at least 6 months, showed a clinically relevant tracheal stenosis. Subclinical tracheal stenosis of at least 10% of the cross-sectioned area was recognized in 46 of 106 patients (43.4%). In the univariate analysis, the degree of stenosis was influenced by the age of the patient (p = 0.044), the duration of intubation prior to PDT (p = 0.042) and by the duration of cannulation (p = 0.006). These parameters had no statistical significance in a multiple regression model. CONCLUSION: When performed by experienced physicians, percutaneous dilatational tracheostomy under fiberoptic guidance is a safe method. The risks of early complications and of clinically relevant tracheal stenoses are low. Subclinical tracheal stenoses are found in about 40% of patients following PDT.

Adolescent↗
PubMed1998

Subtotal adrenalectomy by the posterior retroperitoneoscopic approach.

The retroperitoneoscopic approach offers an established operative procedure for primary adrenal gland tumors. It allows a detailed view of the adrenal gland and its surrounding region. Therefore clear differentiation between normal and neoplastic adrenal tissue is sometimes possible, permitting a planned, unilateral, subtotal resection of the gland. Between July 1994 and August 1997 primary benign adrenal gland tumors (11 Conn adenomas, 4 phenochromocytomas, 4 Cushing adenomas, 3 hormonally inactive tumors; 2.4 +/- 1.2 cm in size; 8 on the right, 14 on the left) were removed from 22 patients by the posterior retroperitoneoscopic approach maintaining tumor-free portions of the ipsilateral adrenal gland. Two patients suffered from bilateral pheochromocytomas associated with multiple endocrine neoplasia (MEN-IIa) syndrome and had previously undergone complete adrenalectomy of the contralateral gland. Following subtotal resection the operating time and blood loss did not differ significantly (p > 0.05) from that seen with complete extirpation (46 patients operated during the same period). All patients with Conn adenomas and pheochromocytomas were biochemically and clinically cured (follow-up 11 months; range 1-31 months). The four patients with Cushing adenoma currently require decreasing cortisol substitution. In the two MEN-II patients adrenal gland cortical function could be maintained; one patient is on low-dose steroid supplementation and the other on none. No local recurrence of tumors has been observed. In selected cases the retroperitoneoscopically performed subtotal adrenal gland resection is a safe procedure that can potentially maintain the function of the adrenal gland cortex.

Adolescent↗
PubMed1998

Pre-operative sequential chemo- and radiochemotherapy in locally advanced carcinomas of the lower oesophagus and gastro-oesophageal junction.

The purpose of this trial was to examine the feasibility of intensive, sequential chemo- and radiochemotherapy followed by surgery in patients with locally advanced carcinomas of the lower oesophagus and the gastro-oesophageal junction (GO junction). The chemotherapy consisted of two courses of 6 weekly administrations of 5-fluorouracil (5-FU) (2.0 g/m2, 24 h infusion) and folinic acid (FA) (500 mg/m2, 2 h infusion) combined with twice weekly cisplatin (50 mg/m2, 1 h infusion). Irradiation of 30 Gy was given concurrently with one course of cisplatin and etoposide. 25 patients with locally advanced (T3-T4 NX M0) squamous cell or adenocarcinoma of the lower oesophagus and GO junction were included and evaluated. Toxicity was usually mild to moderate (WHO grade 1 and 2) with mucositis as the most important side-effect of the pre-operative treatment. Of the patients, 94 and 88% completed the chemo- and radiochemotherapy according to the protocol, respectively. A major response (= partial remission with subjective improvement) to chemotherapy was achieved in 6/10 patients with squamous cell carcinoma and 10/15 with adenocarcinoma. 19 patients had subsequent surgery and complete resection was achieved in 16 (3 patients had intra-abdominal metastases observed at laparotomy). The operative mortality rate was 16% (3/19). 10 of the 16 patients with tumour resection had a pathological complete response. 15 patients (43%) remain alive at a median follow-up of 20 months and the median survival exceeds 16+ months. Our data suggest that this intensive pre-operative chemoradiotherapy programme is feasible and remarkably effective in patients with locally advanced carcinomas of the lower oesophagus or GO junction.

Adenocarcinoma↗
PubMed1998

[Minimally invasive adrenalectomy--comparison of surgical approaches].

Nowadays, minimal invasive operating technique are an essential part of adrenal gland surgery. Meanwhile four different methods are being used: laparoscopically in the supine or lateral position or retroperitoneoscopically as a prone or lateral method. Until now, it is not evident whether laparoscopy or retroperitoneoscopy should be preferred. Laparoscopy offers a familiar anatomical exposure but requires 4-6 trocars. For the retroperitoneoscopic methods only three trocars are needed, whereas orientation in the operating field is more difficult. All endoscopic procedures to the adrenal gland demand high surgical skills. They require expended experience in minimal invasive surgery as well as special knowledge in endocrine surgery.

Adrenalectomy↗
PubMed1998

[Extended resection of locally advanced primary and recurrent rectal carcinomas by interdisciplinary cooperation of various surgical specialties].

Multivisceral resections have been performed on 35 patients with primary and 45 with recurrent rectal cancer. Lethality was 3.7%, morbidity was 9%. Macroscopic adhesions were confirmed histologically as tumorous in 66% of the additionally resected organs. Tumor invasion, tumor recurrence and surgical radicality were found as statistically significant prognostic factors. In radically resected primary tumors 5-yr-survival was 49%. Multivisceral resection in rectal cancer is possible with low morbidity and lethality and potentially curative in primary tumors. In recurrent tumors multivisceral resections are frequently palliative.

Abdominal Neoplasms↗
PubMed1998

[Subtotal retroperitoneoscopic adrenal gland resection--an alternative to adrenalectomy?].

Primary adrenal tumors were removed in 24 patients by the posterior retroperitoneoscopic approach, maintaining tumor-free parts of the ipsilateral adrenal gland. These partial adrenal resections did not cause a significantly different operating time or blood loss compared to 58 complete adrenalectomies performed during the same period. All 20 patients with hormonally active tumors are biochemically and clinically cured (mean follow-up 18 months). In selected cases the retroperitoneoscopic subtotal adrenal gland resection is a safe procedure, which can potentially maintain the function of the adrenal gland's cortex.

Adrenal Gland Neoplasms↗
PubMed1997

[Translaryngeal tracheostomy. Technique and initial results].

Translaryngeal tracheostomy is a new type of minimally invasive technique for bedside tracheostomy in intensive care patients. After percutaneous puncture of the trachea below the first tracheal ring, a conic tracheal cannula is fixed to an orally forwarded guide wire. The cannula is then pulled through in orthograde fashion set up, rotated and pushed forward caudally. Among the first 25 translaryngeal tracheostomies in 24 patients, only two complications appeared: one misplacement of the cannula and one infection of the stoma. During a median apnoea time of about 80 s an average PaCO2 increase of 8.0 +/- 6.8 mm Hg was documented; hypoxias could not be seen. Translaryngeal tracheostomy seems to be an appropriate alternative to established tracheostomy methods.

Aged↗
PubMed1997

[Open approach or Veress needle in laparoscopic interventions? Results of a prospective randomized controlled study].

In a prospective randomized study on 50 patients undergoing laparoscopic surgery, the safety and feasibility of open access laparoscopy was analyzed and compared to the closed Veress needle technique. Open access laparoscopic surgery was performed in half the time needed for the Veress needle technique with equal safety and without complications or technical disadvantages. Furthermore, open access offers economical advantages, as disposable trocars are no longer needed. Therefore the open access technique is recommended as the standard for laparoscopic operations.

Adult↗
PubMed1997

First results of laparoscopic gastrostomy.

BACKGROUND: Laparoscopic gastrostomy as an alternative to open gastrostomy was introduced with various technical variants 5 years ago. However, long-term results of these new methods are still lacking. METHODS: From 4/1993 to 2/1996, laparoscopic gastrostomies were performed on 42 patients (50.9 +/- 15.6 [24-71] years) with esophageal stenosis in locally advanced hypopharyngeal (17 patients) or oropharyngeal (nine patients) carcinoma, incurable esophageal carcinoma (13 patients) and cerebral dyspagia (three patients). Operating time was 38 +/- 11 min [15-65 min]. Procedure-related mortality was 0%. Major complications occurred in 2/42 (4.7%) patients; minor complications were found in 4/42 (9.4%) patients. During a total usage time of 427 months, 14 stoma infections occurred (0.11 infections/100 days). CONCLUSION: Laparoscopic gastrostomy allows a safe, fast, and cheap reestablishment of enteral nutrition. The procedure is minimally invasive and can also be performed under local anesthesia. It has become our method of choice in patients with malignant, nonresectable subtotal stenosis of the hypopharynx or esophagus.

Adult↗
PubMed1997

Association of the TNFa2 microsatellite allele with the presence of colorectal cancer.

Independently, our two groups collaborating in this report performed association studies to consider the influence of the TNF region within the human MHC on the presence of colorectal cancer. In the Glasgow Study, 84 colorectal cancer patients were compared with 91 controls at the TNFa microsatellite locus. Analysis of individual alleles by Fisher's exact test revealed a significant overrepresentation of the TNFa2 allele in the colorectal cancer group, after correcting for multiple comparisons. In the Essen Study, 47 colorectal cancer patients were compared with 117 matched controls, and the hypothesis of TNFa2 overrepresentation in colorectal cancer was confirmed. These data provide evidence for the involvement of the TNF locus in the pathogenetic etiology of colorectal cancer.

Alleles↗
PubMed1997

[Experiences with a vent button system in endoscopic and surgical gastrostomy].

INTRODUCTION: In all variants of surgical or endoscopic gastrostomies, the abdominal wall is penetrated by a catheter. This reduces life-quality and often induces complications in gastrostomies. METHOD: In a prospective trial, an anti-refluxive replacement button was applied as a catheter-substitute in 45 patients after conventional, laparoscopic and percutaneous-endoscopic gastrostomies. RESULTS: In 1 of 45 patients the button was falsely inserted, only two patients experienced minor local infections of the stoma. No further major complications were noted. The average usage-time is 6.3 +/- 4.9 [1-17] months, the rate of complications in 100 days is 0.06. CONCLUSIONS: The gastrostomy replacement button is safely applicable and improves clearly the comfort of gastrostomies with a low complication rate.

Adolescent↗
PubMed1997

[Surgery of primary unilateral adrenal gland tumors--results of 154 patients].

Surgical resection of adrenal neoplasias with endocrine activity is principally indicated. In adrenal neoplasias without endocrine activity, surgical removal is indicated in relation to tumor size. Surgical access and extent of resection are the major problems related to adrenal surgery. From 1980 to 1996, in 154 patients (62 m, 92 f) primary and unilateral adrenal tumors (139 benign, 15 malign) were resected. 93 resections were performed transperitoneally, 13 extraperitoneally, and 48 retroperitoneoscopically. Subtotal adrenal resections were performed in 23 benign tumors smaller than 4 cm. Perioperative lethality was 0%, morbidity was 31.8%. Malignancy was correlated to tumor size: In 114 tumors smaller than 5 cm, no malign neoplasia was found, whereas in 40 tumors larger than 5 cm, 15 specimen were malign. Operating time of the retroperitoneoscopic method was significantly longer than of open procedures (p < 0.05). Postoperative analgotic medication was significantly reduced after endoscopic surgery compared to transperitoneal or extraperitoneal surgery (p < 0.0001). No tumor recurrences occurred after subtotal adrenal resections (mean follow up: 5.7 [1.3 years]). In patients with adrenal carcinomas, 5-year-survival was approximately 15%. In adrenal neoplasias smaller than 5 cm, malignancy is extremely rare. Therefore, less aggressive surgery with a lower morbidity (extraperitoneal approach) and reduced postoperative pain (retroperitoneoscopic approach) including function preserving resection is indicated in these lesions. Due to the high incidence of malignancy, adrenal tumors larger than 5 cm should principally be treated by conventional transperitoneal surgery.

Adolescent↗
PubMed1997

[Instrumental diagnosis for therapeutic decision making in retroperitoneal tumors].

In cases of retroperitoneal soft tissue tumors, individual diagnostic strategies should be chosen. In adrenal gland neoplasias, diagnosis is mainly based on clinical evaluation including ultrasonography, hormone tests, and computed tomography. Magnetic resonance imaging, scintigraphy of the adrenal medulla, and selective adrenal vein sampling are indicated in selected cases. Other procedures are not necessary.

Adrenal Gland Neoplasms↗
PubMed1997

[Laparoscopic gastrostomy--advantages in comparison with percutaneous endoscopic gastrostomy (PEG)].

Laparoscopic gastrostomy was performed on 70 patients with contraindications to PEG. All procedures were performed successfully, even in patients with gastric resections, after gallbladder surgery, and in patients with liver cirrhosis and ascites. Long-term results comprise a low complication rate of 0.12 in 100 application days. Laparoscopic gastrostomy is a highly effective procedure with low morbidity and good long-term results in patients with contraindications to PEG requiring enteral feeding.

Adult↗
PubMed1996

[Leiomyosarcoma of the stomach--clinical aspects, morphology and therapy].

BACKGROUND: Due to the rarity of gastric leiomyosarcomas, only little is known on the results of diagnostics and therapy of these tumors. According to literature, the problem of suitable criteria in determining malignancy of these neoplasms is unsettled. PATIENTS AND METHOD: 21 patients (10 male, 11 female; aged 13 to 74 [53 +/- 13,9] years) with leiomyosarcomas of the stomach were treated from 1978 to 1993. In a retrospective study, the diagnostic and therapeutic results and the pathologic features of these patients are compared with the results of literature. RESULTS: Diagnosis was rarely confined preoperatively. Potentially curative resection was possible in 13/21 cases. Five year survival was 44% overall (R0-resections: 60%, R1/2-resections 22%) with a wide spread of individual cases. Pathologic examination of the tumors showed only half of the tumors classifiable according to the system of McGrath. Some well differentiated tumors revealed unclear malignancy criteria. Analysis of prognostic factors showed no statistically significant influence of surgical radicality but a significant influence of tumor size, mitotic activity and nuclear grading on survival and recurrence. CONCLUSIONS: Because of their rare incidence, the treatment of gastric leiomyosarcomas remains non-standardized. Surgical radical removal of the tumor seems to promise the largest benefit. The treatment of patients with residual or recurrent tumors remains individual, no adjuvant radio- or chemotherapeutical treatment can be generally recommended.

Adolescent↗
PubMed1996

[Implantable catheter systems. Experiences with 1000 patients with central venous ports].

OBJECTIVE: To assess retrospectively duration of functioning and rate of complications of a totally implantable venous access system used for long-term chemotherapy. PATIENTS AND METHODS: Between 1985 and 1993, a central venous access system (Port-a-Cath) had been implanted subcutaneously for long-term chemotherapy in 1000 patients (479 males, 521 females; mean age 49 [15-86] years). Follow-up observations lasted until the end of the chemotherapy or the removal of the system. RESULTS: Mean time of functioning of the catheter system was 284 (2-1563) days. The complication rate was 12.8%: catheter infection in 4.9% and catheter thrombosis in 3.2%. A further 4.7% of patients had less common complications (malfunction, catheter dislocation, skin necrosis, catheter break or disconnection, pneumothorax). A total of 119 (11.9%) systems had to be removed because of complications. The rates of infection and of other complications were significantly lower in patients with solid tumours (2 and 4%, respectively) than in those with haematological disease (6 and 8%) (P < 0.05 for each). CONCLUSION: Totally implantable venous access systems are suitable for long-term chemotherapy and cause few complications.

Adolescent↗
PubMed1996

Posterior retroperitoneoscopy as a new minimally invasive approach for adrenalectomy: results of 30 adrenalectomies in 27 patients.

Posterior retroperitoneoscopic adrenalectomy is a new minimally invasive method. It represents an alternative to conventional open procedures and laparoscopic techniques. Between July 1994 and November 1995 a total of 30 retroperitoneoscopic adrenalectomies were performed on 27 patients. In 24 patients, unilateral tumors were seen (size 1-7 cm): seven Cushing adenomas, five Conn adenomas, seven pheochromocytomas, four hormonally inactive tumors, one cyst. Three patients suffered from Cushing syndrome with bilateral adrenal gland hyperplasias (two inoperable pituitary gland tumors, one bronchial carcinoid with ACTH secretion). The operations were carried out in prone position. After balloon dilatation of the retroperitoneum and creation of a pneumoperitoneum the preparation of the adrenal gland was performed via three trocar sites positioned below the 12th rib. Twenty-five adrenalectomies were completed endoscopically, and five times (among four patients) conversion to the conventional posterior technique was necessary. The average operating time of complete endoscopic adrenalectomies was 124 minutes (45-225 minutes); blood loss was 10 to 120 ml. With minimal need for postoperative analgesia (average dosage 7.9 mg of piritramide), mobilization and adequate food uptake were possible on the day of operation. The posterior retroperitoneoscopic adrenalectomy is a relatively fast, safe method, with the advantages of the posterior open approach and minimally invasive surgery. It therefore represents an important addition to adrenal gland surgery.

Adenoma↗