Roland Zippel

Prospektive Multizenterstudien “Kolon-/Rektumkarzinome” als flächendeckende chirurgische Qualitätssicherung

AbstractIntroduction. Currently, only a small percentage of the diagnostic and therapeutic data on colonic carcinomas has been confirmed by data obtained in randomized controlled studies. For this reason, the results of prospective multicentre observational studies are extremely important. Method. Within a multicentre observational study involving 75 surgical departments carried out between 01.01. and 31.12.1999, 3,756 patients with a colorectal carcinoma (2,293 carcinoma of the colon; 1,463 carcinomas or the rectum) were investigated prospectively using a standardised questionnaire. Results. The OP rate was 98.4%, the resection rate 92.5% (colon 94.1%, rectum 89.9%). The rate of rectal extirpations was relatively high at 30.3%. General postoperative morbidity was 27.4% (colon 27.0%, rectum 27.9%); the specific postoperative morbidity was 24.6% (colon 21.8%, rectum 29.1%). The anastomotic insufficiency rate was 5.2% (colon 3.7%, rectum 9.5%). The 30-day mortality rate was 4.7%, and the postoperative mortality rate 5.7%. Conclusions. Surgical quality control in the form of prospective multicentre observational studies make possible the analysis of the therapeutic situation of a surgical disease under quality assurance aspects. At the same time, the comprehensive data material available will serve the specific planning of prospective randomized studies. With the aid of the present study, a basis for a thorough and complete evaluation of colorectal carcinoma has been created.ZusammenfassungHintergrund. Nur ein geringer Teil der Diagnostik und Therapie des kolorektalen Karzinoms ist derzeit durch prospektiv randomisierte Studiendaten abgesichert. Aus diesem Grund kommt den Ergebnissen prospektiver multizentrischer Beobachtungsstudien ein hoher Stellenwert zu. Methode. Innerhalb einer multizentrischen Beobachtungsstudie wurden vom 01.01.–31.12.1999 an 75 Kliniken 3.756 Patienten mit einem kolorektalen Karzinom (2.293 Kolonkarzinome, 1.463 Rektumkarzinome) mittels eines standardisierten Fragebogens prospektiv erfasst. Ergebnisse. Die Operationsrate betrug 98,4%. Die Resektionsquote lag bei 92,5% (Kolon 94,1%, Rektum 89,9%). Die Rektumexstirpationsquote war mit 30,3% relativ hoch. Die allgemeine postoperative Morbidität betrug 27,4% (Kolon 27,0%, Rektum 27,9%), die spezifische postoperative Morbidität 24,6% (Kolon 21,8%, Rektum 29,1%). Die Anastomoseninsuffizienzrate lag bei 5,2% (Kolon 3,7%, Rektum 9,5%). Es war eine 30-Tage-Letalität von 4,7% und eine postoperative Letalität von 5,7% zu verzeichnen. Schlussfolgerung. Chirurgische Qualitätssicherung in Form von prospektiven multizentrischen Beobachtungsstudien ermöglicht die Analyse der Behandlungssituation eines chirurgischen Krankheitsbildes unter qualitätssichernden Aspekten. Gleichzeitig wird mit dem vorliegenden umfangreichen Datenmaterial die gezielte Planung von prospektiv randomisierten Studien unterstützt. Mit dieser Studie wurden die Grundlagen für eine bundesweite Erfassung der kolorektalen Karzinome geschaffen.

Effect of caseload on the short-term outcome of colon surgery: results of a multicenter study

Abstract This prospective multicenter study investigated the effect of hospital caseload on early postoperative outcome of surgery for carcinoma of the colon in 75 German hospitals and included 2293 patients. The hospitals were divided into those with a caseload of 1–30 (group A), 31–60 (group B), and more than 60 (group C) operations. Increasing caseload was associated only with fewer general postoperative complications. It was also associated with significantly greater use of antibiotic prophylaxis. No significant differences between the groups were found in resection rates, intraoperative complications, specific postoperative complications, overall postoperative morbidity, hospital mortality, or 30-day mortality. The significance of hospital caseload for the short-term postoperative outcome following surgery on the colon should not be overestimated. Basing conclusions about the results to be expected simply on the case volume is impermissible. On the basis of the available data it is not possible to establish a threshold value, that is, a minimum number of required operations.

Digital image analysis for morphometric evaluation of tissue response after implanting alloplastic vascular prostheses.

The aim of this study was to examine the suitability of digital image analysis, using the KS400 software system, for the morphometric evaluation of the tissue response after prosthesis implantation in an animal model. Twenty-four female pigs aged 10 weeks were implanted with infrarenal Dacron(R) prostheses for 14, 21, 28, and 116 days. Following the explantation and investigation of the neointima region, the expression of beta-1-integrin, the proliferation rate by means of Ki-67 positive cells, and the intima thickness were evaluated as exemplary parameters of the tissue response after implantation. Frozen tissue sections were immunohistochemically stained and subsequently examined using computer-aided image analysis. A maximum expression of 32.9% was observed for beta-1-integrin 14 days after implantation, gradually declining over time to 9.8% after 116 days. The proliferation rate was found to be 19% on day 14, increasing to 39% on day 21 with a subsequent gradual decline to 5% after 116 days. The intima thickness increased from 189.9 microm on day 14 to 1228.0 microm on day 116. In conclusion, digital image analysis was found to be an efficient and reproducible method for the morphometric evaluation of a peri-prosthetic tissue response.

Time course of fibronectin in the peri-implant tissue and neointima formation after functional implantation of polyester-based vascular prostheses with different porosity in pigs

Intima hyperplasia, resulting from extracellular matrix (ECM) secretion, can lead to vascular prosthesis occlusion and is a major problem in vascular surgery. Fibronectin might contribute to ongoing ECM secretion. However, the exact role of fibronectin and its influence on neointima formation remains unclear. This study was aimed at investigating the time course of the fibronectin area fraction and neointima formation following the functional implantation of three different polyester vascular prostheses into pigs. The infrarenal aorta from 15 animals (n = 5/group) was replaced by prosthesis segments with low, medium and high primary porosity. After 7, 14, 21, 28 and 116 days, the prostheses were morphometrically examined. Overall, the fibronectin area fraction was inversely correlated with the neointima thickness, demonstrating high fibronectin levels in the early phase (days 7 and 14) and low levels in the later phase with almost complete neointima formation (days 21-116). Throughout the study, fibronectin levels were highest at the proximal anastomosis region. The low porosity prosthesis had the highest fibronectin area fraction and a delayed neointima formation in the middle phase (days 21 and 28) but the highest neointima lining on day 116. The results indicate a relationship between fibronectin and neointima formation with the prosthesis porosity, demonstrating the importance of the textile design for tissue reactions following implantation.

Der Einfluss der Oberflächen-Beschichtung auf die humorale Immunreaktion gegen implantierte Polyester-Gefäβprothesen im Tiermodell

Foreign-body reaction is an obligatory subsequence of biomaterial implantation whose extent can be determined on the one hand from the implant surface, and on the other through individual factors. This study investigates individual, humoral immune response in LEW.1A rats after repeat i.m. implantation of commercially available polyester vascular prostheses coated with different substances (collagen = G1, gelatin = G2, human serum albumin = G3) as well as from a poly-tetrafluoroethylene control graft prosthesis (G4). Sham procedures in control animals were designated G5. Serum sample Ab detection was performed by enzyme immunoassay employing polymer particles of a non-impregnated polyester prosthesis as a target. In contrast to the G4 & G5 groups, all animals with polyester implants demonstrated a differentiated anti-polymer Ab development (G2 > G3 > Gl). Polymer Ab prevalence was 100% for G2 + G3 on day 22. For Gl it was a maximum of 71.4%. Only G3 revealed a specific Ab reaction to the surface-coating as well as the strongest overall immunological reaction. G4 demonstrated no specific Ab development against polytetrafluoroethylene. Our results have showed a specific immune reaction which varied not only as a result of the applied polymer, but also due to the surface-coating as well as individual factors.

Die Bedeutung der Erfahrung für die Ergebnisse in der Rektumchirurgie anhand einer prospektiven Multizenterstudie / The Role of Caseload Experience for the Short-Term Results Achieved in Rectal Surgery: Results of a Prospective Multicentre Study

Die Untersuchung wurde in Form einer prospektiven Multizenterstudie an 75 ostdeutschen Kliniken vom 1.1.–31.12.1999 durchgefuhrt. Es wurden 3756 Patienten er-fast, davon 1463 mit einem Rektumkarzinom. Es erfolgte eine Unterteilung der Kliniken in solche mit einer Fallzahl von 40 behandelten Patienten mit einem Rektumkarzinom. Die Gruppen waren identisch in Hinblick auf Alter, Geschlecht, Grose, Gewicht, Tumorstadien, Risikofaktoren, ASA-Klassifikation. Die Rektumexstirpationsrate war bei einer Fallzahl uber 40 Patienten/Jahr und die postoperative Morbiditat bei einer Fallzahl von uber 20 Patienten/Jahr signifikant vermindert. Der Wert einer grosen Fallzahl fur die Ergebnisse in der Rektumchirurgie liegt in einer signifikanten Reduktion der Rektumexstirpationsraten und in der Verminderung der postoperativen Morbiditat.