Pharmakokinetische Untersuchungen bei der Tumeszenz-Lokalanästhesie mit Prilocain in der Varizenchirurgie

Tumeszenz-Lokalanästhesie (TLA) mit Prilocain gewährleistet eine ausgezeichnete Analgesie in der Varizenchirurgie ohne die Nachteile der Vollnarkose und Spinalanästhesie. Bei TLA werden große Volumina einer stark verdünnten (0,09%igen) Tumeszenzlösung, bestehend aus 1000 mg Prilocain, 1,0 mg Adrenalin und 10 mEq Natriumbikarbonat in 1000 ml physiologischer Kochsalzlösung subkutan entlang der zu operierenden Venen infiltriert. Ziel: Die Studie hatte den Zweck, die zeitlichen Verlaufskurven der Plasma-Prilocainkonzentration (PPC) und Methämoglobin (Met-Hb)-Werte nach TLA mit Prilocain in bestimmten Intervallen über 24 Stunden zu ermitteln. Methode: Untersucht wurden 3 Gruppen von je 8 Patienten (n = 24) mit 10, 15 bzw. 20 mg/kg Prilocain als TLA. Ergebnis: Die entsprechenden Spitzenwerte der mittleren PPC wurden 7 bis 9 Stunden nach TLA erreicht und betrugen 0,47, 0,51 bzw. 0,71 _g/ml. Erste zentral neurotoxische Symptome können bei einer PPC von 5 _g/ml auftreten. Die kritische Krampfschwellenkonzentration beträgt 10-12 _g/ml. Bei Lokalanästhesie in konventioneller Technik werden mehrfach höhere Spitzen-Plasmaspiegel des Anästhetikums innerhalb der ersten Stunde erreicht. Bei 5 Patienten wurde simultan Met-Hb bestimmt. Methämoglobinämie ist eine potentielle Komplikation von höheren Prilocain- Dosierungen. Maximale Met-Hb-Werte von 0,3 bis 11,0% des Gesamt-Hb wurden durchschnittlich 14 Stunden nach TLA gemessen. Zyanose entsteht bei Met-Hb-Werten von 15% des Gesamt-Hb. Bei keinem Patienten traten klinische Komplikationen auf. Schlußfolgerungen: TLA mit Prilocain in Dosierungen bis zu 20 mg/kg verursacht sehr niedrige maximale PPC und Met-Hb- Konzentrationen, die weit unter den kritischen toxischen Grenzen liegen. Aufgrund dieser Ergebnisse kann die TLA unter klinischen, pharmakokinetischen und damit forensischen Gesichtspunkten als ein sicheres und unbedenkliches Anästhesieverfahren in der Varizenchirurgie angesehen werden.

Chirurgie der Vena giacomini

Die Vena giacomini verbindet das Stromgebiet der oberflächlichen Stammvenen Vena saphena magna (VSM) und Vena saphena parva (VSP) im Sinne einer kollateralen Vernetzung. Sie wird häufig sowohl in der präoperativen Diagnostik wie auch während der Operation aufgrund ihrer variablen Anatomie und der schweren Zugänglichkeit übersehen oder vernachlässigt. Die V. giacomini stellt dadurch bei Stammvarikosis von VSM und/ oder VSP eine pathophysiologische Verbindung her, wodurch die Insuffizienz der einen Stammvene auf die andere übertragen werden kann und Rezidiventwicklung begünstigt wird. Anhand von 173 Fällen werden Problematik, Konzepte und Strategien der Chirurgie dieser Vene dargestellt.

[Phlebology in German departments of dermatology. An analysis on behalf of the German Society of Phlebology]

BACKGROUND

Phlebologic diseases have become extremely common and have major socio-economic impact. However, the percentage of dermatologists working in phlebology appears to be decreasing according to the data of the German Society of Phlebology (DGP).

METHODS

To investigate the reasons for this development, we--on behalf of the DGP--sent a questionnaire to 120 German Departments of Dermatology in autumn 2012.

RESULTS

In 76 returned questionnaires, the number of physicians with additional fellowship training in phlebology averaged 1.5; the average number of those who fulfill the criteria for training fellows in phlebology was 0.9. In 71.1 % of the departments there was a phlebologist. A special phlebologic outpatient clinic existed in 73.7 % of the departments. Sonography with Doppler (89.5 %) and duplex (86.8 %) was used as the most frequent diagnostic tool. For therapy, compression (94.7 %), sclerotherapy (liquid 78.9 %, foam 63.2 %, catheter 18.4 %), endoluminal thermic procedures (radio wave 28.9 %, laser 17.1 %) and surgery (especially crossectomy and stripping 67.1 %, phlebectomy of tributaries 75 %) were used. The average number of treatments was very heterogenous in the different departments.

CONCLUSIONS

Phlebology definitely plays an important role in dermatology. Most departments fulfill the formal criteria for the license to conduct advanced training in phlebology. A wide spectrum of phlebological diagnostic and therapeutic procedures is available.

[Operations for varicose veins in the elderly]

Based on 200 patients treated this way--regarding our series of approx. 12,000-13,000 venous operations--the following statements can be made: This procedure may be carried out on both, out- and inpatients at every age. According to the mentality of the patients, there are no complaints at all, or complaints just during the first few days after operation, such as pain caused by pressure. We did not observe any decrease of vitality or any complications like circumscribed phlebitis or after-bleedings. Postoperatively, the intravenous pressure is significantly improved. The surgical procedure--which is usually carried out to clear secondary manifestations, not for cosmetic reasons--results in quick healing of the ulcerations, as well.

[Significance of the ankle joint pump for returning venous blood. Report of experiences using a mechanical treatment method]

We report on new medicomechanic equipment designed for the improvement of the venous reflux in the lower extremity. It may be employed as postoperative prophylaxis against thrombosis and in the treatment of secondary manifestations based on venous insufficiency, as well as with pathological changes caused by ankylosis of the ankle.

[Surgical problems of perforating vein insufficiency]

Following a short description of the normal and variant anatomy, the surgical procedures involved in treating perforating veins are described, with special reference to operative problems. Surgical difficulties can be avoided by paying proper attention to the surgical indications, correct preoperative clarification, a technically meticulous technique, and adequate postoperative therapy.

[Surgical therapy of late x-ray-induced skin lesions]

The method as well as the degree of surgery in treatment of skin lesions induced by radiation must be individually planned, considering site and severity of the lesions. On account of insufficient blood supply and, consequently, high susceptibility to infection, only myocutaneous or full thickness grafts are suitable for the covering of the defects. Due to reduced elasticity, high tension at the receptor site often leads to rejection of the transplant. These problems are illustrated by some cases showing lesions on the face, breast, and abdominal wall; the difficulties of treatment are discussed.

[Polychondritis chronica atrophicans]

Report on a patient suffering from relapsing polychondritis, who showed the cardinal manifestations on ears, eyes and joints, as well as a leucocytoclastic vasculitis and erythema nodosum-like lesions. Corticosteroids (prednisone 50 mg daily) have been effective in controlling all clinical symptoms.

[Surgical therapy of venous circulatory disorders]

After a short historical review of the operative methods concerning the varicotomy some principles of the modern varicotomy were pointed out which should be noticed in case of a so-called "standard operating technique". In accordance with the opinion of most of the authors it has turned out that the insufficient main trunk varices together with eventually occurring dobbled cords of veins should be extracted, whereby in the area of orifice of the long saphenous vein (venae saphena magna) all side branch veins are ligated after proper preparation. Larger side branches have to be post-sclerosed or interrupted by stab incision. The perforator vein (venae perforantes) in the area of the Cockett group (communicantes) and the arcade veins must not be neglected, otherwise real recidivation could be the result. Furthermore it is evident for the operation that the number of incisions has to be kept as minor as possible and even the length of incision should be reduced to a minimum, for short incisions normally heal up without any scars. The performance of such a satisfying cosmetic surgery is absolutely conditioned by corresponding instrument.