- Email: [email protected]
Transdiaphragmatic approach to the descending thoracic aorta for proximal control during surgery on the abdominal aorta
Transdiaphragmatic Approach to the Descending Thoracic Aorta for Proximal Control during Surgery on the Abdominal Aorta Brian Buxton, MB, MS, FRACS, FRCS, FACS, Victoria, Australia George Red, Jr, MD, FACS, Houston, Texas Denton A. Cooley, MD, FACS, Houston, Texas
The establishment of proximal control is usually necessary during surgery on the abdominal aorta. In most patients this is readily obtained by clamping near the renal arteries. However, in some patients with abdominal aortic aneurysm or in patients undergoing a second procedure on the aorta, it is difficult to dissect around the aorta in the region of the renal arteries and it is necessary to clamp more proximally. The upper abdominal aorta is difficult to mobilize and an alternative method of achieving proximal control is to divide the diaphragm and clamp the descending thoracic aorta.
curved aortic clamp passed through the incision in the diaphragm. (Figure 2.) Care should be taken during manipulation of the clamp to prevent injury of the aorta or $ercostal vessels. Once the clamp has been applied, the structures in the upper abdomen will keep it away from the operative field. Retrograde bleeding from the branches of the upper abdominal aorta can be minimized by the introduction of a balloon catheter into the proximal abdominal aorta After completion of the operative procedure, the &nnp is removed through the diaphragm, which is left unrepaired.
Operatlve Technic
A midline incision carried to the xiphoid provides adequate access to the lower thoracic and upper abdominal aorta. With the stomach drawn to the left and the left lobe of the liver retracted superiorly, the lesser omentum is divided to the right of the upper stomach and lower esophagus to display the median arcuate ligament overlying the junction of the thoracic with the abdominal aorta. A vertical incision is then made in the posterior part of the diaphragm between the median arcuate ligament and the esophageal hiatus, through which the aorta can be palpated and mobilized by blunt dissection from the loose connective tissue of the posterior mediastinum. (Figure 1.) Because of its deep position, it is difficult and probably unnecessary to encircle the aorta. The aorta can be clamped from side to side with a slightly
From the Departments of Surgery, University of Mkbourne, and Austin Hospital. Heidelberg, Victoria, Australia, and the Texas Heart Institute, Houston, Texas. Reprint requests should be addressed to Brian Buxton, MB, MS, Waningal Private Consulting Suite, Box 141, Heidelberg, Victoria 3084, Australia.
726
Figure 1. Incision in the posterior aspect of the diaphragm between the median arcuate Ilgament and the esophageal hiatus.
The American Journal of Surgery
Technic for Abdominal Aortic Surgery
Comments
Control of the descending thoracic aorta may be useful during surgical correction of a ruptured abdominal aortic aneurysm or an aneurysm which extends proximally. The technic may be of value also in the treatment of renal or other visceral arterial lesions, when a clamp placed nearby could interfere with the surgical procedure. Second operations on the abdominal aorta in the region of the renal vessels are difficult and dissection around the aorta at this level may be hazardous; under these circumstances, control of the aorta above the diaphragm offers an easy alternative. In complex lesions of the left ventricular outflow tract, where it is elected to create a bypass from the left ventricle to the abdominal aorta, exposing the descending thoracic aorta by dividing the diaphragm allows implantation of a bypass graft at the junction of the descending thoracic and upper abdominal aorta [2]. An advantage of controlling the aorta in the chest, compared with the abdomen, lies in the ease with which the aorta can be mobilized. The lower descending thoracic aorta lies free in the loose con-
nective tissue of the posterior mediastinum, from which it can be easily dissected. Further, the descending thoracic aorta is relatively free from atheroma and is easy to clamp. In contrast, the upper abdominal aorta is surrounded by the celiac ganglia and the crura of the diaphragm and is covered by the peritoneum and pancreas. In addition, the upper abdominal aorta has many branches which add to the difficulty in mobilization. For this reason, some surgeons have used an atraumatic aortic occluder in this area [3]. A surgical procedure high in the abdominal aorta, for example renal artery repair, can be performed more readily with the aortic clamp in a proximal position, thus leaving a greater length of aorta beyond the clamp. Transdiaphragmatic control of the thoracic aorta during an intraabdominal procedure is simpler than making a separate thoracotomy as described by Soyer et al [4]. A disadvantage of this technic is that the descending thoracic aorta may be difficult to expose, and care is required to avoid damage during either mobilization or clamping. The procedure requires additional dissection and therefore should be reserved for special situations in which the usual infrarenal exposure of the aorta is inadequate. Clamping the aorta in the chest does not produce as dry an operative field as clamping below the renal arteries, and additional measures, such as the passage of an intraluminal balloon catheter, may be necessary
Summary
A technic of mobilizing and clamping the lower descending thoracic aorta from the abdomen through the incision in the diaphragm is described. This technic is simple and may be useful when it is difficult to obtain proximal control of the abdominal aorta during surgery. In addition, certain surgical procedures on the upper abdominal aorta may be facilitated by the use of this technic. References 1. Berkowitz HD, Roberts B: New technique for control of ruptured
F/gore 2. Curved aortlc clamp being passed through the inciskn In the dlaphragm to clamp the descendhtg Wrack aorta.
abdominal aortic aneurysm. Surg Gynecol Dbstet 133: 107, 1971. 2. Cooley DA, Norman JC, Mullins CE, Grace RR: Left ventricle to abdominal aortic conduit for relief of aortic stenosis. Cardiovast Dfs Bull Tex Heart lnst 2: 376, 1975. 3. Conn J, Trippel OH, Bergan JJ: A new atraumatic aortlc occluder. Surgery 64: 1158, 1968. 4. Soyer R, Eisenmann B, Deloche A, Diamant Berger F, Haas Cl, Dubost Ch: Traitement des anevrysmes romputs de I’aorte sous-r&tale par clampage de I’aorte thoracique descendante et mise a plat “premiere” de la poche anevrysmale. La Nouvelle Presse Medicale 3: 8 1, 1974.
727
The establishment of proximal control is usually necessary during surgery on the abdominal aorta. In most patients this is readily obtained by clamping near the renal arteries. However, in some patients with abdominal aortic aneurysm or in patients undergoing a second procedure on the aorta, it is difficult to dissect around the aorta in the region of the renal arteries and it is necessary to clamp more proximally. The upper abdominal aorta is difficult to mobilize and an alternative method of achieving proximal control is to divide the diaphragm and clamp the descending thoracic aorta.
curved aortic clamp passed through the incision in the diaphragm. (Figure 2.) Care should be taken during manipulation of the clamp to prevent injury of the aorta or $ercostal vessels. Once the clamp has been applied, the structures in the upper abdomen will keep it away from the operative field. Retrograde bleeding from the branches of the upper abdominal aorta can be minimized by the introduction of a balloon catheter into the proximal abdominal aorta After completion of the operative procedure, the &nnp is removed through the diaphragm, which is left unrepaired.
Operatlve Technic
A midline incision carried to the xiphoid provides adequate access to the lower thoracic and upper abdominal aorta. With the stomach drawn to the left and the left lobe of the liver retracted superiorly, the lesser omentum is divided to the right of the upper stomach and lower esophagus to display the median arcuate ligament overlying the junction of the thoracic with the abdominal aorta. A vertical incision is then made in the posterior part of the diaphragm between the median arcuate ligament and the esophageal hiatus, through which the aorta can be palpated and mobilized by blunt dissection from the loose connective tissue of the posterior mediastinum. (Figure 1.) Because of its deep position, it is difficult and probably unnecessary to encircle the aorta. The aorta can be clamped from side to side with a slightly
From the Departments of Surgery, University of Mkbourne, and Austin Hospital. Heidelberg, Victoria, Australia, and the Texas Heart Institute, Houston, Texas. Reprint requests should be addressed to Brian Buxton, MB, MS, Waningal Private Consulting Suite, Box 141, Heidelberg, Victoria 3084, Australia.
726
Figure 1. Incision in the posterior aspect of the diaphragm between the median arcuate Ilgament and the esophageal hiatus.
The American Journal of Surgery
Technic for Abdominal Aortic Surgery
Comments
Control of the descending thoracic aorta may be useful during surgical correction of a ruptured abdominal aortic aneurysm or an aneurysm which extends proximally. The technic may be of value also in the treatment of renal or other visceral arterial lesions, when a clamp placed nearby could interfere with the surgical procedure. Second operations on the abdominal aorta in the region of the renal vessels are difficult and dissection around the aorta at this level may be hazardous; under these circumstances, control of the aorta above the diaphragm offers an easy alternative. In complex lesions of the left ventricular outflow tract, where it is elected to create a bypass from the left ventricle to the abdominal aorta, exposing the descending thoracic aorta by dividing the diaphragm allows implantation of a bypass graft at the junction of the descending thoracic and upper abdominal aorta [2]. An advantage of controlling the aorta in the chest, compared with the abdomen, lies in the ease with which the aorta can be mobilized. The lower descending thoracic aorta lies free in the loose con-
nective tissue of the posterior mediastinum, from which it can be easily dissected. Further, the descending thoracic aorta is relatively free from atheroma and is easy to clamp. In contrast, the upper abdominal aorta is surrounded by the celiac ganglia and the crura of the diaphragm and is covered by the peritoneum and pancreas. In addition, the upper abdominal aorta has many branches which add to the difficulty in mobilization. For this reason, some surgeons have used an atraumatic aortic occluder in this area [3]. A surgical procedure high in the abdominal aorta, for example renal artery repair, can be performed more readily with the aortic clamp in a proximal position, thus leaving a greater length of aorta beyond the clamp. Transdiaphragmatic control of the thoracic aorta during an intraabdominal procedure is simpler than making a separate thoracotomy as described by Soyer et al [4]. A disadvantage of this technic is that the descending thoracic aorta may be difficult to expose, and care is required to avoid damage during either mobilization or clamping. The procedure requires additional dissection and therefore should be reserved for special situations in which the usual infrarenal exposure of the aorta is inadequate. Clamping the aorta in the chest does not produce as dry an operative field as clamping below the renal arteries, and additional measures, such as the passage of an intraluminal balloon catheter, may be necessary
Summary
A technic of mobilizing and clamping the lower descending thoracic aorta from the abdomen through the incision in the diaphragm is described. This technic is simple and may be useful when it is difficult to obtain proximal control of the abdominal aorta during surgery. In addition, certain surgical procedures on the upper abdominal aorta may be facilitated by the use of this technic. References 1. Berkowitz HD, Roberts B: New technique for control of ruptured
F/gore 2. Curved aortlc clamp being passed through the inciskn In the dlaphragm to clamp the descendhtg Wrack aorta.
abdominal aortic aneurysm. Surg Gynecol Dbstet 133: 107, 1971. 2. Cooley DA, Norman JC, Mullins CE, Grace RR: Left ventricle to abdominal aortic conduit for relief of aortic stenosis. Cardiovast Dfs Bull Tex Heart lnst 2: 376, 1975. 3. Conn J, Trippel OH, Bergan JJ: A new atraumatic aortlc occluder. Surgery 64: 1158, 1968. 4. Soyer R, Eisenmann B, Deloche A, Diamant Berger F, Haas Cl, Dubost Ch: Traitement des anevrysmes romputs de I’aorte sous-r&tale par clampage de I’aorte thoracique descendante et mise a plat “premiere” de la poche anevrysmale. La Nouvelle Presse Medicale 3: 8 1, 1974.
727