The Portal Venous System: Its Roentgen Anatomy

With the advent and development in recent years of successful surgical treatment of portal hypertension (1, 2, 3, 15) in the form of the veno-venous shunt, there has naturally arisen a demand for roentgen visualization of the portal system as an aid in intelligent treatment planning. Previously, surgeons who performed such shunting procedures were forced to embark upon them with little or no preoperative information on the particular anatomical configuration of the portal vessels. Much of the operative time, therefore, was consumed in locating the various trunks. The type of shunting operation was either decided preoperatively, without any knowledge of the particular anatomical relationships, or after extensive exploratory dissection of the upper abdomen, with or without differential venous pressure readings. Surgeons experienced in this field have not infrequently encountered an inoperable anatomical situation only after a long, arduous dissection. In an earlier publication (16), roentgen visualization of the portal venous bed was described and evaluated as a factor in operative planning. In the same communication some reference was made to the normal x-ray appearance. It is the intent of this paper to present in greater detail the roentgen anatomy of the normal portal venous system. For the interpretation of films made after contrast visualization of the portal system, a thorough knowledge of its roentgen anatomy is necessary. This knowledge can be gained in part from numerous exhaustive anatomical investigations based on dissection of cadavers (7, 9, 10). This, we believe, in view of our present studies, may be implemented by a familiarity with the roentgen appearance of the intact portal circulation. For evaluation of these roentgen features of the portal venous bed, two methods were utilized: (a) injection of the portal system in cadavers and (b) portography in the living subject in the course of surgery for conditions other than those involving this system. By injection of the cadavers, detailed study of the anatomy of all the principal veins of the portal system has been made possible. By injection of the portal system at surgery, the hemodynamics of the portal bed, as well as some of the anatomical features, have been elucidated. It is chiefly, however, the hemodynamics which have been revealed through the latter method. Method of Study In the postmortem material, the portal systems of 50 fresh adult cadavers were injected to capacity (150 to 200 c.c.) with a barium-water mixture made up of 12 oz. water, 4 oz. barium, 2 teaspoonfuls of Petrogalar. One of the branches of the superior or inferior mesenteric veins was doubly ligated and the upper ligature was left open. A polyethylene catheter was then inserted into the proximal portion of the vein. The injection was continued until visible filling of the small branches of the portal system was observed.