Pulmonale Thrombendarterektomie: Die Therapie der chronisch thromboembolischen pulmonalen Hypertension— Initiale chirurgische Erfahrung

Zusammenfassung Grundlagen Die pulmonale Thrombendarterektomie stellt eine effektive Therapie zur Behandlung von Patienten mit chronisch thromboembolischer pulmonalar Hypertonie dar. Wir berichten über unsere Erfahrungen mit dieser Operationstechnik bei den ersten 9 Patienten. Methodik Zwischen 1992 und Oktober 1994 wurde bei 9 Patienten eine pulmonale Thrombendarterektomie durchgeführt. über eine mediane Sternotomie wurden die Pulmonalarterien beider Seiten bis in ihre subsegmentalen Aufzweigungen im Sinne einer echten Endarterektomie vom organisierten thromboembolischen Material befreit. Zumeist waren Perioden des totalen Kreislaufstillstandes in tiefer Hypothermie notwendig, wobei diese zunehmend verkürzt werden konnten und 3 Patienten vollst?ndig ohne Kreislaufstopp operiert wurden. Ergebnisse Die perioperative Mortalit?t betrug 11%, wobei der 1. Patient am 14. postoperativen Tag an den Folgen eines Reperfusions?dems verstarb. Alle anderen Patienten sind 4 bis 22 Monate (im Mittel 13 Monate) nach dem Eingriff am Leben und zeigen eine Hochsignifikante Verbesserung ihrer h?modynamischen Situation (mean PAP pr?operativ: 62 mm Hg, postoperativ: 30 mm Hg p<0,001; Cardiac Index pr?operativ: 2,1 1/min/m², postoperativ: 3,6 l/min/m² p=0,001). W?hrend pr?operativ alle Patienten in NYHA-Klasse III oder IV waren, sind die 8 überlebenden jetzt alle in Klasse I oder II. Schlu?folgerungen Die pulmonale Thrombendarterektomie bietet eine erfolgreiche Therapiem?glichkeit für Patienten mit chronisch thromboembolischer pulmonaler Hypertonie mit einer in Anbetracht fehlender konservativer Altermativen akzeptablen Mortalit?t und ausgezeichneten funktionellen Langzeitergebnissen.      

Physiological incompatibilities of porcine hepatocytes for clinical liver support.

In fulminant hepatic failure, the use of bioartificial liver support (BAL) with porcine hepatocytes is the subject of a current and controversial debate.1 Specifically, the issue of cross-species physiological incompatibilities has not been addressed so far. We therefore investigated the effects of species-specific cytokines in single and cocultures on hepatocyte function. Hepatocyte cultures were isolated from human resection specimens and from Landrace pigs. Single and cocultures were exposed to porcine and human interleukin (IL)-6 or tumor necrosis factor (TNF)-alpha. Changes in expression of C-reactive protein (CRP), albumin, CCAAT enhancer binding protein (C/EBP)-alpha and C/EBP-beta and metabolic competence of cultured cells was studied by measuring testosterone metabolite production. After human or porcine IL-6 dosing, CRP was induced up to 100-fold in human hepatocyte cultures, while porcine hepatocytes responded marginally (2- to 5-fold). Treatment with human or porcine IL-6 or TNF-alpha resulted in reduced albumin production, albeit at different levels when human and porcine hepatocytes were compared (P = 0.001). Unlike human, porcine hepatocytes produced less of 6alpha-hydroxytestosterone (6alpha-HT) (P < 0.001) and 7alpha-HT (P < 0.001) after human or porcine IL-6 dosing and treatment with species-specific TNF-alpha induced (human hepatocytes) or decreased (porcine hepatocytes) 6beta-HT production (P = 0.021). In coculture with free exchange of metabolites, porcine hepatocytes produced less 6alpha-HT (P = 0.048) and 16alpha-HT (P = 0.033), whereas after treatment with human IL-6 reduced CRP gene and protein expression was observed with human hepatocytes (P = 0.013). In conclusion, species-specific responses of hepatocytes to cytokines and interactions with xenobiotic metabolites may limit the clinical effectiveness of porcine hepatocytes in BAL.     

Experimental hydranencephaly in the ovine fetus

Hydranencephaly is defined as the replacement of a previously normal brain, in whole or in part, by membranous fluid-filled sacs. The etiology is not well understood, and the time course of development is unknown. Fifteen ovine fetuses were chronically cannulated and had both carotid arteries ligated at 100 days of gestation (term is 145–150 days). They were killed at 1 (n = 4), 2 (n = 6) and 4 (n = 5) weeks post-surgery, and the findings compared with those of 25 age-matched controls. By 2 weeks post-surgery the entire cerebral hemispheres and diencephalon had been replaced by fluid closely resembling cerebrospinal fluid. The choroid plexus, pituitary and brain stem remained outwardly normal, but the cerebellum showed signs of damage. Fetuses maintained normal values for blood gases and hematocrit up to 4 weeks post-surgery, and grew normally. Light microscopy of the brain stem showed significant losses of cell populations in the medulla by 4 weeks. Vascular casting and acute blood flow studies in an additional group of fetuses showed that the entire brain was perfused via the vertebral-occipital anastomosis immediately after acute bilateral carotid clamping, but that the blood flow rate was insufficient to maintain adequate oxygen delivery. Received: 4 August 1995 / Revised, accepted: 30 November 1995     

A randomized controlled trial of electromagnetic therapy in the primary care management of venous leg ulceration

OBJECTIVE: The aim was to establish the potential efficacy, tolerabilityand side-effect profile of electromagnetic therapy as an adjunctto conventional dressings in the treatment of venous leg ulcers. METHOD: A prospective, randomized, double blind controlled clinicaltrial was carried out in a dedicated leg ulcer clinic basedin one urban general practice. Nineteen patients with leg ulcersof confirmed venous aetiology were assessed. The main outcomemeasures were rate and scale of venous leg ulcer healing, changesin patient-reported pain levels, quality of life, degree ofmobility, side effect profile and acceptability to patientsand staff. RESULTS: Sixty-eight per cent of patients attending this dedicated clinicachieved improvements in the size of their ulcer (4, 21%, healedfully) and in reduced pain levels (P < 0.05) during the trial,despite the chronicity of ulcer histories. Patients treatedwith electromagnetic therapy at 800 Hz were found at day 50to have significantly greater healing (P < 0.05) and paincontrol (P < 0.05) than placebo therapy or treatment with600 Hz. All patients reported improved mobility at the end ofthe study. The electromagnetic therapy was well tolerated bypatients, with no differences between groups in reporting adverseevents, and proved acceptable to staff. CONCLUSION: Despite the small numbers in this pilot study, electromagnetictherapy provided significant gains in the healing of venousleg ulcers and reduction in pain. Keywords. Electromagnetic therapy, RCT, leg ulcers, primary care.