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M K Walz

Publications and source records attributed to M K Walz.

At least 19 recordsLinked to original sources
PubMed2002

[Tracheostomy. Indications, methods, risks].

Tracheostomy is one of the oldest procedures in surgery. Although it was traditionally used for treatment of upper airway stenosis, the primary surgical indication is now in the long-term intensive care unit patient. Here, the aims are avoidance of damage to the larynx, earlier weaning from artificial respiration and improved nursing care. Apart from the conventional operating method, minimally invasive procedures have been increasingly employed. More than 20,000 ICU patients per annum are now treated in Germany by these modern methods. Common features of these procedures are the initial puncture of the trachea with subsequent dilatation of the puncture channel. Current meta-analyses of prospectively randomised studies show a lower complication rate than with conventional methods. Furthermore, serious sequelae such as tracheal stenosis are rare in the long-term course. However, conventional operative tracheostomy still has its place, particularly in circumstances where the new methods are contraindicated.

Critical Care↗
PubMed2002

[Laparoscopic splenectomy by the "Essen-manoeuvre" for treatment of benign and malignant haematological diseases].

Despite its early description, laparoscopic splenectomy has not yet reached the level of a standard operation as a therapeutic option for haematological disease, especially for malignant disorders. We performed laparoscopic splenectomies in a modified 4 port technique and dissection of the splenic vessels by the "Essen-Manoeuvre" and report on 68 attempted laparoscopic splenectomies for benign (n = 42) and malignant (n = 26) haematological disorders. Conversion rate was 9 %, 30-days-mortality was 1.4 %, perioperative morbidity was 11 %, respectively. Accessory spleens were found and resected in 17 % of our patients. Laparoscopic splenectomy is a new minimally invasive option for patients with benign and malignant haematological disease fraught with a special risk of intraoperative bleeding.

Adolescent↗
PubMed2001

Laparoscopic splenopexy by peritoneal and omental pouch construction for intermittent splenic torsion ("wandering spleen").

Wandering spleen is an extremely rare anatomic variant with potentially serious clinical implications. Usually, splenectomy is advocated for treatment of this disease. Various methods for preserving the wandering spleen by means of splenopexy have been described, including two reports on laparoscopic splenic refixation. We describe the third case in which laparoscopic splenopexy was used to manage chronic intermittent splenic torsion. In a 25-year-old woman, splenopexy was successfully performed by laparoscopic reposition and fixation of the spleen by omental pouch creation. At laparoscopy with a normal operating room setup and four trocars, a free-floating, macroscopically normal spleen attached to an abnormally long vascular pedicle with no gastrosplenic or phrenicosplenic ligaments was detected in the lower right quadrant. The spleen was repositioned and placed in the left phrenorenal angle. Splenopexy was achieved by suturing the left colophrenic ligament to the lateral diaphragm, thus creating a pouch for the inferior part of the spleen, and by suturing the gastrocolic ligament to the anterior diaphragm to create a pouch for the upper splenic pole. The postoperative course was uneventful. At a follow-up examination 3 months after the operation, the patient was well, with no further episode of recurrent abdominal pain. Ultrasonographically, the spleen was seen easily in the left hypochondrium in its normal physiologic position. Laparoscopic splenopexy is a useful option for organ-preserving therapy of the wandering spleen.

Adult↗
PubMed2001

[Tracheostomy: indications, methods, risks].

Tracheostomy is one of the most ancient procedures in surgery. Although it was traditionally used for treatment of upper airway stenosis, its primary surgical indication is now in the long-term intensive care unit patient. Here, the aims are avoidance of damage to the larynx, earlier weaning from artificial respiration, and improved nursing care. Apart from the conventional operating method, minimally invasive procedures have been increasingly employed. More than 20,000 ICU patients per annum are now treated in Germany by these modern methods. Common features of these procedures are the initial puncture of the trachea with subsequent dilatation of the puncture channel. Current meta-analyses of prospectively randomised studies show a lower complication rate than with conventional methods. Furthermore, serious sequelae such as tracheal stenosis are rare in the long-term course. However, conventional operative tracheostomy still has its place, particularly in circumstances where the new methods are contraindicated.

Adolescent↗
PubMed2001

[Video-assisted hemithyroidectomy: surgical technique and early results].

To date, there are only very few data on minimally invasive thyroid surgery. In a prospective study (11/99-11/00), videoscopically assisted hemithyroidectomy was performed on 18 patients (3 M, 15 F; age 22-56 years) with uninodular thyroid disease. The length of the cervical incision was between 15 and 25 mm; 8 patients were operated on using initial gas insufflation and 10 patients with a gasless technique. The mean operative time was 96 +/- 23 min, significantly longer than in a conventionally operated group (n = 26) during the same period. No complications were observed. Videoscopically assisted hemithyroidectomy is feasible and can be considered in selected patients.

Adult↗
PubMed2001

Posterior retroperitoneoscopic adrenalectomy: lessons learned within five years.

Posterior retroperitoneoscopic adrenalectomy is one of the new endoscopic methods in endocrine surgery. In a prospective clinical study 142 posterior retroperitoneoscopic adrenalectomies (72 right, 70 left) were performed in 130 patients (52 males, 78 females, age 49.1 +/- 14.9 years). Indications were primary adrenal tumors (unilateral, n = 118; bilateral, n = 2), adrenal metastases (n = 2), and bilateral ACTH-dependent hyperplasias (n = 10). Tumor size ranged from 0.5 to 7.0 cm (mean 2.7 +/- 1.4 cm). Partial adrenalectomies were performed in 39 patients. Conversion to open posterior adrenalectomy was necessary in five patients and seven procedures (5%). Intraoperative and postoperative complications were minor and occurred in 5% and 13%, respectively. Mortality was zero. Operating time was 101 +/- 39 minutes (range 35-285 minutes) and depended on tumor type (pheochromocytoma versus others; p < 0.01), tumor size (< 3 vs. > or = 3 cm; p < 0.05), gender (p < 0.05), and extent of resection (partial versus complete, p < 0.05. Twenty-three adrenalectomies (17%) were performed within 1 hour or less. Blood loss was 54 +/- 72 ml. Consumption of analgesics was low (mean 6 mg piritramide postoperatively). Median duration of hospitalization was 3 days. Posterior retroperitoneoscopic adrenalectomy is a safe method that has become a standard procedure in endocrine surgery.

Adenoma↗
PubMed2001

Linear and non-linear dynamics of heart rate variability in brain dead organ donors.

Recent studies outlined linear and non-linear dynamics in heart rate variability; however, their physiological origin is still unknown. The present study investigated the impact of cerebral function on linear and non-linear dynamics in heart rate variability. Electrocardiograms from seven brain dead organ donors and seven healthy volunteers were analyzed. Atropine was used in healthy volunteers to adjust their heart rate to that of the donors. As compared to healthy volunteers without atropine, the linear dynamics of heart rate variability, determined by time and frequency domain analyses, were significantly reduced in healthy volunteers with atropine and, to an even greater extent, in donors. Atropine tended to increase the complexity and non-linearity of heart rate variability in healthy volunteers, as determined by the correlation dimension D and the largest Lyapunov exponent L, respectively (D = 9.43 +/- 2.93 vs. 7.65 +/- 0.97 and L = 0.525 +/- 0.099 vs. 0.504 +/- 0.047 bits.beat-1; both NS), while these indices were significantly reduced in donors by 19.5 +/- 12.8% and 15.0 +/- 11.7%, respectively (D = 6.16 +/- 0.98 and L = 0.428 +/- 0.059 bits.beat-1; both p < 0.05 vs. volunteers). Thus, loss of cerebral function reduces both linear and non-linear components of heart rate variability.

Adult↗
PubMed2001

Laparoscopic gastrostomy: results of 121 patients over 7 years.

Laparoscopic gastrostomy was introduced in various technical variants 7 years ago. However, larger series and long-term results of these new methods are still lacking. In a prospective study, laparoscopic gastrostomies were performed by two institutions in 121 patients (88 men, 33 women; mean age, 58.3 +/- 11.16 years [range, 24-82]) with esophageal stenosis in locally advanced hypopharyngeal or oropharyngeal carcinoma, incurable esophageal carcinoma, and cerebral dysphagia. Operating time was 40 +/- 22 (range, 10-160) minutes. Procedure-related mortality was 0%, early mortality was 1.6%, the overall intraoperative complication rate was 7.4%, and the early complication rate was 9.9%. During a cumulative usage time of 1086.2 months, the complication rate in 1000 usage days was 0.8, and the stoma infection rate was 0.65. Laparoscopic gastrostomy is a reliable method for safe and economic establishment of enteral nutrition, even in patients for whom long-term nutrition by gastrostomy is expected.

Adult↗
PubMed2001

Minimal protection of the liver by ischemic preconditioning in pigs.

Ischemic preconditioning (IP) protects the rat liver. In pigs, in which hepatic tolerance to ischemia is similar to that in humans, information on IP is lacking. Therefore, in enflurane-anesthetized pigs, hepatic vessels were occluded for 120 min (protocol 1) or 200 min (protocol 2) without (control) and with IP (3 times 10 min ischemia-reperfusion each). In protocol 1, cumulative bile flow (CBF) during reperfusion was greater in IP (47.3 +/- 5.2 ml/8 h) than in control (17.1 +/- 7.8 ml/8 h, P < 0.05). ATP content tended to recover toward normal during reperfusion in IP, whereas it remained at ischemic levels in control. Serum enzyme concentrations increased similarly during reperfusion, and <1% hepatocytes were necrotic or stained terminal deosynucleotidyl transferase-mediated dUTP nick-end labeling-positive in control and IP groups. In protocol 2, no differences in CBF, ATP, or serum enzyme concentrations during reperfusion were measured between control and IP groups, except for a somewhat reduced lactate dehydrogenase in IP. The number of necrotic or terminal deosynucleotidyl transferase-mediated dUTP nick-end labeling-positive hepatocytes tended to be greater in the IP than the control group. Thus IP provides some functional protection against reversible ischemia but no protection during prolonged ischemia in pigs.

Adenosine Triphosphate↗
PubMed2000

[Endoscopic excision of extra-adrenal pheochromocytomas (paragangliomas)].

We describe the successful endoscopic removal of six extra-adrenal pheochromocytomas in three patients. One neoplasia was located retrocavally, two between the aorta and vena cava, two by the para-aortal, and one by the parailiacal. The tumors were removed by the posterior retroperitoneoscopic or by the anterior laparoscopic approach, respectively. The intraoperative and postoperative courses were uneventful.

Adrenal Gland Neoplasms↗
PubMed2000

Intraperitoneal and retroperitoneal carbon dioxide insufflation evoke different effects on caval vein pressure gradients in humans: evidence for the starling resistor concept of abdominal venous return.

BACKGROUND: The authors hypothesized that intraperitoneal and retroperitoneal carbon dioxide insufflation during surgical procedures evoke markedly different effects on the venous low-pressure system, induce different inferior caval vein pressure gradients at similar insufflation pressures, and may provide evidence for the Starling resistor concept of abdominal venous return. METHODS: Intra- and extrathoracic caval vein pressures were measured using micromanometers during carbon dioxide insufflation at six cavity pressures (baseline and 10, 15, 20, and 24 mmHg and desufflation) in 20 anesthetized patients undergoing laparoscopic (supine, n = 8) or left (n = 6) or right (n = 6) retroperitoneoscopic (prone position) surgery. Intracavital, esophageal, and gastric pressures also were assessed. Data were analyzed for insufflation pressure-dependent and group effects by one-way and two-way analysis of variance for repeated measurements, respectively, followed by the Newman-Keuls post hoc test (P < 0.05). RESULTS: Intraperitoneal, unlike retroperitoneal, insufflation markedly increased, in an insufflation pressure-dependent fashion, the inferior-to-superior caval vein pressure gradient (P < 0.00001) at the level of the diaphragm. In contrast to what was observed with retroperitoneal insufflation, transmural intrathoracic caval vein pressure increased at 10 mmHg insufflation pressure, but the increase flattened with an insufflation pressure of more than 10 mmHg, and pressure decreased with an inflation pressure of 20 mmHg (P = 0.0397). These data are consistent with a zone 2 or 3 abdominal vascular condition during intraperitoneal and a zone 3 abdominal vascular condition during retroperitoneal insufflation. CONCLUSIONS: Intraperitoneal but not retroperitoneal carbon dioxide insufflation evokes a transition of the abdominal venous compartment from a zone 3 to a zone 2 condition, presumably impairing venous return, supporting the Starling resistor concept of abdominal venous return in humans.

Anesthesia, Inhalation↗
PubMed2000

No protection of the porcine kidney by ischaemic preconditioning.

One or more episodes of sublethal ischaemia and reperfusion delay infarct development during subsequent, sustained ischaemia in the heart and skeletal muscle. The present study tested whether or not such ischaemic preconditioning (IP) also protects the kidney. Enflurane-anaesthetized pigs underwent 60 min of right renal vessel occlusion (RVO), followed by 8 h of reperfusion without (placebo group, n = 8) or with three preceding cycles of 10 min RVO and 10 min reperfusion (IP group, n = 8). After 8 h of reperfusion, kidneys were oliguric in both groups (placebo group: 23 +/- 21 ml x h(-1), IP group: 24 +/- 27 ml x h(-1)). A transient polyuric phase occurred in the IP group at 2 h reperfusion. The reperfused kidneys did not excrete inulin, creatinine or urea in both groups, although renal blood flow during reperfusion was similar to baseline. Morphological damage ranged in both groups from single cell necrosis to disseminated patchy necrosis; the number of pyknotic cells tended to be higher in the IP group than in the placebo group (27.0 +/- 7.1 vs. 15.6 +/- 5.6%, n.s.). In anaesthetized pigs, IP did not therefore attenuate renal dysfunction and morphological damage resulting from 60 min of renal normothermic ischaemia followed by 8 h of reperfusion.

Animals↗
PubMed1999

Tracheal lesion caused by percutaneous dilatational tracheostomy--a clinico-pathological study.

OBJECTIVE: To analyse the accuracy of cannula placement and the extent of tracheal lesions of the anterior tracheal wall after percutaneous dilatational tracheostomy (PDT). DESIGN: A clinico-pathological study of tracheal specimens following PDT. SETTING: University hospital. MATERIALS: Forty-two tracheal specimens of intensive care patients (24 male, 18 female; age: 23-70 years) who died unrelated to tracheostomy. INTERVENTIONS: Using tracheoscopic guidance, PDTs were performed by Ciaglia's method. Tracheal cannulas with outer diameters of 11-12 mm were used. The duration of cannulation ranged from 1 to 97 days (median: 10.5 days). RESULTS: PDTs were placed between the 1st and 4th tracheal rings in 32 cases, above the first ring in 7 cases and below the 4th in 3 cases. Twenty specimens showed a horizontal intercartilaginous rupture of the anterior tracheal wall, 12 tracheas additionally had fractures of tracheal rings and in 10 specimens defects of tracheal cartilage (range: 15 mm2-120 mm2) were found. The occurrence of tracheal defects was influenced by the height of puncture (p<0.05) and duration of cannulation (p<0.01). CONCLUSION: Misplacement of the tracheal cannula above or below the intended tracheal area occurred in one-fourth of our patients. The typical tracheal lesion following PDT is transverse rupture of the anterior tracheal wall with or without fracture of neighbouring rings. Extended cartilaginous defects are rare, which may explain the low rate of tracheal stenosis following PDT.

Adult↗
PubMed1999

Induction chemotherapy followed by concurrent chemotherapy and high-dose radiotherapy for locally advanced squamous cell carcinoma of the cervical oesophagus.

The efficacy and toxicity of combined radiochemotherapy for locally advanced squamous cell carcinomas of the cervical oesophagus was evaluated retrospectively. Induction chemotherapy consisted of three courses of 5-fluorouracil (5-FU), leucovorin, etoposide and cisplatin (FLEP) or two courses weekly six times of 5-FU and leucovorin combined with biweekly cisplatin. This induction regimen was followed by high-dose external beam radiotherapy up to 60-66 Gy and concurrent chemotherapy with cisplatin and etoposide. Median follow-up of the recruited 17 patients was 37 months (13-73 months). Long-term survival was 24% at 2 and 3 years. The probabilities of locoregional tumour recurrences and distant metastases as sites of first relapse were 67 and 39% at 2 years. Acute and late toxicity of this schedule was moderate. The protocol offers a definitive chance of long-term survival for patients with locally advanced carcinomas of the cervical oesophagus, but local in-field recurrences remain the predominant risk after treatment. Intensification of the regimen seems possible because no dose-limiting late toxicities were observed.

Adult↗