Randomization of autogenous vein and polytetrafluorethylene grafts in femoral-distal reconstruction

A randomized, prospective, controlled study comparing autogenous saphenous vein and polytetrafluoroethylene (PTFE) grafts in infrainguinal arterial reconstructions has been initiated in three different institutions. A total of 446 operative procedures were divided into six groups, depending on the site of distal bypass insertion into the popliteal or an infrapopliteal artery and on whether the patient received a randomized vein or PTFE graft or an obligatory PTFE graft. The randomized saphenous vein graft patency to infrapopliteal arteries was significantly better (P less than 0.005) at 2 1/2 years than the patency of randomized or obligatory PTFE grafts to the same level. No significant differences between randomized vein grafts and randomized or obligatory PTFE grafts in the femoropopliteal position could be demonstrated up to 2 1/2 years, either above or below the knee. The need for such a study and the limitations of this preliminary report are discussed. The requirement for longer observation of greater numbers of cases is stressed. A current plan for usage of the PTFE graft in the lower extremity is presented.     

Prognostic indicators in femoropopliteal reconstructions.

The incidence of early failure in 115 vein femoropopliteal grafts has been analyzed for the presence of reliable prognostic indicators of such failures. One hundred twelve patients had preoperative Doppler ultrasound assessment; 98 had intraoperative graft flow measured. Early graft failure was more prevalent in patients with rest pain and gangrene and in patients with poor runoff. Neither of these two findings had predictive value. Ninety-one percent of patients with a pressure index (ankle systolic pressure/brachial systolic pressure) less than 0.20 had early graft thrombosis. This suggests that arterial reconstruction is futile in this group. Measurement of vein graft flows intraoperatively was of value. Grafts with basal flows less than 70 ml/min uniformly thrombosed. There was significant correlation between ankle pressure index and intraoperative vein graft flow (r=.52). Both ankle pressure index and intraoperative vein graft flow provide prognostic indications of graft failure and should be of value in selecting patients for femoropopliteal reconstructions.     

Prophylactic regimens in colorectal surgery: Comparisons between metronidazole used alone or with ampicillin for one or three days

The purpose of this study was to compare as anti-infectious prophylaxis in elective colorectal cancer surgery the effect of metronidazole alone and in combination with ampicillin, and the effect of a duration of 1 or 3 days of prophylaxis. The prophylactic regimens designated regimens A-D given in randomized order were metronidazole 500 mg used alone or with 2.0 g ampicillin administered every 8 hours as separate but simultaneous infusions. All patients studied received preoperative mechanical evacuation of bowel contents. Eight surgical departments participated in the study. Two hundred thirty-three patients were studied. The distribution of sex, age, and type of operation was similar among the groups of patients receiving each regimen, except that there were more cases of sigmoidectomy, low anterior resection, or rectal amputation in the group receiving regimen D. The duration of the operations was comparable, even for each type of operation considered separately. Samples for bacteriological examination were obtained by abscess punctures when relevant. The pus was taken and transported to the laboratory under anaerobic conditions. Moderate or severe infections were observed in 6 (10.3%) of 58 patients on regimen A, in 2 (3.5%) of 58 patients on regimen B, in 4 (7.0%) of 57 receiving regimen C, and in 2 (3.3%) of 60 given regimen D. The highest incidence of postoperative infections was observed in rectal amputation. The bacteria causing postoperative infections were similar in the regimens A and C receiving only metronidazole for 1 and 3 days, respectively and in regimens B and D in which ampicillin was added. Only one anaerobe, aClostridium perfringens, was recovered from regimen C; twenty-two strains of anaerobic bacteria were recovered from regimen A. The number of aerobic bacteria was 25 in regimen A and 16 in regimen C. The yield of bacteria was much more sparse when metronidazole was combined with ampicillin. Eleven isolates (2 anaerobes) were recovered from regimen B, only one isolate was recovered from patients on regimen D, an indole positiveProteus. In conclusion, th'is study indicates that a combination of metronidazole and ampicillin is particularly useful in rectal surgery. Metronidazole alone may suffice in colonic surgery, but a combination with an agent against aerobes is recommended in rectal surgery. The difference between 1-day prophylaxis and 3-day prophylaxis was insignificant for metronidazole plus ampicillin; a single day of this prophylactic regimen would appear advisable.

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Resumen El propósito de este trabajo ha sido el de comparar, en la profilaxis anti-infecciosa en cirugía colorectal electiva, el efecto de: (a) metronidazol solo y en combinación con ampicilina, y (b) la profilaxis de un día con la de tres días de duración. Los 4 regimenes profilácticos designados como regímenes A-D, y suministrados al azar, fueron metronidazol 500 mg utilizado como agente único o con ampicilina 2.0 g en infusiones simultáneas cada 8 horas iniciadas una hora antes de la operación. Todos los pacientes del estudio también fueron sometidos a evacuación mecánica del contenido intestinal según el procedimiento de rutina en cada hospital. Ocho departamentos quirúrgicos participaron en el estudio, el cual incluyó 233 pacientes. La distribución según sexo, edad y tipo de operación fué similar, excepto que hubo un mayor número de casos de sigmoidectomía, resección baja anterior o amputación rectal en el grupo que recibió el regimen D. La duración de las operaciones fué comparable, aún para cada tipo de operación considerado aisladamente. Se obtuvieron cultivos por punción de abscesos cuando se consideró pertinente, y el pus fué tomado y transportado al laboratorio bajo condiciones anaeróbicas. Infecciones moderadas o severas fueron observadas en 6 de 58 pacientes (10.3%) en el regimen A, en 2 de 58 en el regimen B (3.5%), en 4 de 57 en el regimen C (7.0%) y en 2 de 60 en el regimen D (3.3%). La mayor incidencia de infección postoperatoria se encontró en casos de amputación rectal. Las bacterias causantes de las infecciones postoperatorias fueron similares en los regimenes A y C que recibieron sólo metronidazol por 1 o por 3 días respectivamente, y en los regimenes B y D en que se añadió ampicilina. Sólo un anaerobio, unClostridium perfringens, fué recuperado en el regimen C, y 22 cepas de bacterias anaerobias en el regimen A. El numéro de bacterias aeróbicas fué de 25 en el regimen A y 16 en el regimen C. La proliferación bacteriana fué mucho menor cuando se combinó el metronidazol con la ampicilina. Once cultivos positivos (2 anaerobios) fueron logrados en el regimen B, y sólo uno en el regimen D, unProteus indol-positivo. En conclusión, este estudio indica que la combinación de metronidazol y ampicilina es particularmente útil en cirugía rectal. El metronidazol solo puede ser suficiente en cirugía colónica, pero su combinación con un agente efectivo contra los aerobios es recomendable en cirugía rectal. La diferencia entre la profilaxis de un día y la de 3 días fué insignificante para la combinación de metronidazol y ampicilina; un único día de profilaxis parece ser el regimen recomendable.

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Résumé Le but de l'étude entreprise par les auteurs fut de comparer l'effet prophylactique anti-infectieux du métronidazole employé isolement ou en association avec l'ampicilline pendant 1 ou 3 jours. Quatre protocoles différents désignés par les lettres A.B.C.D. ont été ainsi pris en considération. L'étude a été conduite en série par tirage au sort. Cinq cent (500) mg de métronidazole employé isolement ou en association avec 2 g d'ampicilline ont été injectés séparément 3 fois par 24 heures pendant 1 jour ou 3 jours. L'intestin ayant été évacué par les moyens mécaniques classiques.Huit services de chirurgie ont participé à l'étude qui a groupé 233 malades. Le sexe, l'âge, le type et la durée de l'opération ont été sensiblement identiques pour les 4 groupes avec cependant un nombre plus important de sigmoidectomies, de résections abdominales antérieures du rectum ou d'amputations rectales dans le groupe D.Selon les cas, les spécimens de pus ont été prélevés au tampon au niveau de l'incision pariétale ou par ponction en présence d'abcès collectés. Le pus prélevé a été transporté au laboratoire en milieu anaérobie. Les résultats ont été les suivants: chez 6 des 58 malades (10,3%) soumis au protocole A (500 mg de métronidazole × 3 en 24 heures), chez 2 des 58 sujets (3,5%) soumis au régime B (500 mg de métronidazole et 2 g d'ampicilline × 3 en 24 heures), chez 4 des 57 patients (7%) soumis au régime C (500 mg de métronidazole × 3 en 24 heures pendant 3 jours) et chez 2 des 60 opérés (3,3%) soumis au régime D (500 mg de métronidazole et 2 g d'amicilline × 3 en 24 heures pendant 3 jours) fut observée une infection modérée ou grave. Le taux le plus élevé d'infections postopératoires a été constaté après amputation du rectum.Les bactéries à l'origine de l'infection ont été identiques quel qu'ait été le protocole prophylactique anti-infectieux suivi. L'emploi du métronidazole isolé s'est soldé par la présence de 22 types de bactéries anaérobie pour le protocole A et un type seulement pour le protocole C de 25 types de bactéries aérobies pour le protocole A et de 16 pour le protocole C. L'association métronidazole et ampicilline s'est soldé par un nombre plus clairsemé de types bactériens: 11 dont 2 anaérobies pour le protocole B et un seul (protéus) pour le protocole D.En conclusion, cette étude permet d'affirmer que la combinaison du métronidazole et de l'ampicilline est particulièrement efficace dans la chirurgie rectale.Le métronidazole isolé est suffisant en cas de chirurgie colique mais son association avec un agent exerçant son action sur les germes aérobies est recommandé dans la chirurgie rectale. La différence entre le traitement prophylactique d'une durée d'un jour ou de trois jours ayant été insignifiante lorsque le métronidazole était associé à l'ampicilline. Un traitement prophylactique pendant 24 heures suivant ce protocole apparaît suffisant.

     

Computer processed 99mTc-DTPA studies of renal allotransplants.

In order to refine the diagnostic possibilities of the radionuclide renal study in transplanted patients and to compensate for the nonspecificity of the 131I-hippuran study in some situation, 99mTc-DTPA WAS USED SIMULTANEOUSLY FOR IMAGING AND TIME-ACTIVITY CURVES. For these curves to be significant, appropriate background subtraction had to be made with a simple computer-processing method. The results obtained have shown that it is possible to distinguish marked acute tubular necrosis from milder degrees, thus affording a prognostic index in the immediate postoperative period, when the hippuran data are often nonspecific. Further, the diagnosis and follow-up of acute rejection episodes can be improved by the DTPA processed curves. Although these curves when examined individually do not show a specific pattern for rejection, they may reveal striking evolutionary changes when compared to the previous studies, even when the hippuran curves are unchanged. The physiologic basis for the differences between the two time-activity curves may be related to the differential handling of the two radiopharmaceuticals by the kidney.     

The importance of anal endosonography in the evaluation of idiopathic fecal incontinence

PURPOSE: The aim of the study was to evaluate the use of anal endosonography in idiopathic incontinence. METHODS: In 29 patients and 26 normal controls, the relationship between sonography images and physiologic parameters was studied. RESULTS: External anal sphincter function, measured as fiber density by single-fiber electromyography (P=0.0001) and pudendal nerve terminal motor latency (P=0.04), was significantly impaired in patients with idiopathic incontinence compared with controls. Both the external and internal anal sphincter could be identified by anal endosonography, and the thickness directly measured. The thickness of the external anal sphincter was significantly negatively correlated to muscle fiber density (r=–0.65,P=0.0002) and to pudendal nerve distal conduction velocity (r=–0.74,P=0.008). The thickness of the internal anal sphincter was significantly correlated to resting pressure (r=–0.67,P=0.0001). CONCLUSION: The ratio between the thickness of the external and internal sphincter muscles measured on the sonography screen was significantly reduced in patients with neurogenic incontinence compared with controls (P <0.01).     

Pharmacokinetics of bacmecillinam and pivmecillinam in volunteers

Summary The pharmacokinetics of bacmecillinam and pivmecillinam were studied in healthy fasting volunteers given tablets in a cross-over, randomized order. The mean (±SD) peak levels of plasma mecillinam were 1.43±0.34, 2.73±0.43, and 4.62±1.41 mg/l after bacmecillinam 100, 200, and 400 mg and 2.38±0.65 mg/l after pivmecillinam 400 mg. The corresponding areas under plasma Vs time curves (AUC) were 2.21±0.19, 3.99±0.63, and 7.74±1.38 mg·h·l^–1 for bacmecillinam and 5.35±0.93 mg·h·l^–1 for pivmecillinam. The elimination half-lives were 0.8–1.1h for bacmecillinam and 0.7h for pivmecillinam. The 12 h urinary recovery of unchanged mecillinam after the 400 mg doses was 41% for bacmecillinam and 30% for pivmecillinam. The 400 mg dose of bacmecillinam gave a significantly higher plasma peak (p<0.001), AUC (p<0.001) and urinary recovery (p<0.001) than did pivmecillinam 400 mg. The plasma peaks appeared earlier and the rate of absorption was higher after bacmecillinam than after pivmecillinam (p<0.05). In conclusion, bacmecillinam had a better bioavailability than pivmecillinam in the tablet formulations studied. The AUC increased linearly with increasing doses of bacmecillinam.