Use of the BioMedicus centrifugal pump in traumatic tears of the thoracic aorta

Traumatic blunt thoracic aortic injury is a clinical entity of increasing incidence. After the diagnosis of traumatic tear of the aorta is made, there is some controversy over whether the aorta should be repaired using cardiopulmonary bypass, a heparinized shunt, or cross-clamping and graft interposition without a shunt or bypass. At Allegheny General Hospital, 19 patients were treated for traumatic tears of the thoracic aorta between July 1, 1977, and June 30, 1983. They can be divided into two groups: Group 1 (July 1, 1977, through October 31, 1981), in which no shunt or bypass or only a heparinized shunt was used, and Group 2 (November 1, 1981, through June 30, 1983), in which left atrium-femoral artery bypass was performed using a BioMedicus heparinless pump and tubing. Among the 10 patients in Group 1, 4 died and 2 had paraplegia postoperatively. Among the 9 patients in Group 2, 1 died and none experienced paraplegia following operation. We believe that the BioMedicus centrifugal pump is a simple, safe means of perfusing the lower body, kidneys, and spinal column without necessitating heparinization in a patient with multiple injuries or the placement of a cumbersome heparinized shunt. Because of the simplicity and the reliability demonstrated, this pump should be considered for use in all patients with traumatic tears of the thoracic aorta.     

Clinical and Experimental Evaluation of Left Ventriculoiliac Shunt Bypass during Repair of Lesions of the Descending Thoracic Aorta

Temporary ventriculoiliac bypass with a tridodecylmethylammonium chloride-coated shunt has been used routinely at the University of North Carolina for the past seven years for repair of lesions of the descending thoracic aorta. Although the technique appears to be safe and reliable, the hemodynamic effects of prolonged nonvalved apical diversion on left ventricular function are not defined. To evaluate left ventricular performance during ventriculoiliac shunt bypass, the procedure was investigated in adult sheep. Systolic flow through the shunt was pulsatile and accounted for approximately 35% of the total cardiac output. Reversed flow was minimal. No significant change occurred in cardiac output, left ventricular end-diastolic pressure, or left atrial pressure. Perfusion of the abdominal viscera through the shunt was sufficient to prevent intestinal and renal ischemia. Our results indicate that the shunt provides left ventricular decompression without evidence of deterioration in left ventricular performance for up to three hours of apical bypass and aortic occlusion.It is included that bypass with a left ventriculoiliac shunt provides safe and effective diversion during repair of lesions of the descending thoracic aorta and offers an excellent alternative to methods involving greater technical hazard or requiring systemic anticoagulation.     

Surgical Treatment of Aortic Aneurysms

Two bypass techniques were used in 21 patients with aneurysms of the descending thoracic aorta. Sixteen patients had a conventional left-heart bypass with heparin, and five patients had a local shunt without heparin. The local shunt technique is described. The use of a local shunt instead of left-heart bypass considerably reduced operation time, duration of bypass and blood consumption. The local shunt technique is simple and safe. The equipment is minimal and the method can be applied without the delay involved in setting up cardio-pulmonary bypass.     

Aneurysms of the descending aorta: Surgical experience with three methods of adjunct procedures

Thirteen patients were surgically treated for the repair of aneurysms of the descending aorta, using three different types of adjunct procedures—an external temporary bypass with a vascular prosthesis, a tridodecylmethylammonium chloride (TDMAC) or a partial cardiopulmonary bypass. There was no operative death, though one patient died 73 days following surgery. Significant intraoperative morbidity occurred in 3 patients: one had ventricular fibrillation and the other two massive hemorrhages. There was no instance of paraplegia or renal failure. The only significant complication that developed was pulmonary insufficiency in two patients with a pump bypass. The mean operative time and the mean aortic occlusion time in patients with the TDMAC shunt were shorter than the times in patients with the vascular prosthetic shunt or the pump bypass. TDMAC shunt required no special equipment and cannulation was simpler and safer.     

Clamp/repair: a safe technique for treatment of blunt injury to the descending thoracic aorta

Debate exists with regard to the use of pump bypass, shunt bypass, or clamp/repair techniques in treating injuries to the descending thoracic aorta. The objective in using any of these techniques is to minimize the complications of paraplegia and renal failure, while achieving the lowest possible mortality. During an eighteen-year period, 45 patients were seen with acute blunt injury to the descending thoracic aorta. The shunt bypass method of repair was used in 1; pump bypass in 8; and clamp/repair in 23. There were desperate unsuccessful attempts to resuscitate and control hemorrhage in 13 patients, 1 of whom was placed on portable pump bypass. Thirty-two patients survived resuscitation and operation, and 26 were long-term survivors. Among surviving patients with permanent paraplegia, 2 underwent pump bypass and 1, the clamp/repair technique. Four other patients were seen with paraplegia or paresis and had reversal of the paralysis. The clamp/repair technique was used in these patients with clamp times ranging from 35 to 62 minutes (mean, 47.4 +/- 13.3 minutes). Renal failure did not occur in any patient, despite clamp times of up to 62 minutes (mean, 37.5 minutes). Excluding patients seen in a moribund condition, mortality most often was secondary to neurological or multisystem injury. Debate continues concerning intraoperative management of this highly lethal vascular injury. The data presented here support the historical composite experience that clamp/repair is a safe and efficacious technique that minimizes paraplegia and mortality.     

Spinal cord ischemia following operation for traumatic aortic transection

The danger of irreversible ischemic damage to the spinal cord following repair of traumatic aortic rupture has prompted many techniques designed to decrease this risk. Surgical repair was performed on 41 consecutive patients, using four different methods. These included: group 1 (15 patients), left-heart pump bypass with systemic administration of heparin; group 2 (7 patients), heparinized shunt from the ascending aorta to the descending aorta or to the femoral artery; group 3 (14 patients), heparinized shunt from the left ventricle to the aorta or femoral artery; group 4 (5 patients), aortic cross-clamp only. Spinal cord ischemia was not seen in groups 1 or 2, but paraparesis or paraplegia developed in 4 patients in group 3. Severe shock accompanied rupture in all patients in group 4, and no time was taken for a shunt or bypass. Four of the 7 deaths occurred in the operating room in patients who had arrived moribund and in severe shock. In our experience, shunts from the left ventricle to the aorta have failed to protect the spinal cord against ischemia. Left-heart bypass or aorta-to-aorta shunts are now our procedure of choice.     

Arterial Shunt with Pump Infusion Line for the Treatment of Chronic Thoracic Aortic Aneurysms: The "Modified Shunt of Gott"

Dissection of the aneurysm is the most dangerous step during graft replacement of the descending thoracic aorta. Sudden hemorrhage may follow wall rupture or disruption of major collaterals before the aorta can be clamped. A simple modification of the classic Gott is illustrated, which makes the shunt work also as a partial bypass if needed, with rapid reinfusion of blood losses. Nineteen of 25 patients requiring resection of descending aortic aneurysms from 1982 to 1990 were treated with this method with no mortality.     

Traumatic rupture of the thoracic aorta.

Eleven patients with aortic rupture secondary to non-penetrating thoracic trauma, recent in four patients and of longer standing in seven, have been operated upon. Every patient with an acute injury had a widened mediastinum in the chest skiagram. The diagnosis of traumatic rupture was made by aortography in each case. The operative procedure involved cardiopulmonary bypass, left heart bypass or aorta to aorta bypass shunt. There was one postoperative death. It is recommended that in the acute stage a rupture of the aorta secondary to trauma should be repaired as soon as possible, while ruptures of long standing should be electively repaired.     

TRAUMATIC RUPTURE OF THE THORACIC AORTA

Eleven patients with aortic rupture secondary to non-penetrating thoracic trauma, recent in four patients and of longer standing in seven, have been operated upon. Every patient with an acute injury had a widened medlastinum in the chest skiagram. The diagnosis of traumatic rupture was made by aortography in each case. The operative procedure involved cardiopulmonary bypass, left heart bypass or aorta to aorta bypass shunt. There was one postoperative death. It is recommended that in the acute stage a rupture of the aorta secondary to trauma should be repaired as soon as possible, while ruptures of long standing should be electively repaired.     

Anesthesia and monitoring for aortic aneurysm surgery

Cardiopulmonary bypass is employed in the treatment of aneurysms of the ascending aorta and transverse aortic arch. Anesthesia in these cases is similar to that used in the treatment of cardiac lesions requiring cardiopulmonary bypass. Most surgeons use some form of bypass or shunt for aneurysms in the distal arch, descending thoracic aorta, and the thoracoabdominal aortic segment. My surgical associate replaces these lesions with grafts without bypass or shunt, using simple cross-clamping technique. This paper is concerned with anesthetic technique and general supportive measures that provide safety for this method of treatment. Anesthesia and muscle relaxation is obtained by drugs that do not depress the myocardium. Surgical exposure and lung protection are facilitated by one lung ventilation, collapsing the left lung with a double lumen endobronchial tube. Blood pressure and cardiac hemodynamics are extensively monitored and controlled by administration of intravenous fluids and nitroprusside, as indicated. Serum electrolytes, blood gases, plasma osmolarity, acid-base balance, and body temperature are frequently monitored and maintained in safe range. Blood coagulability is assessed and normal ranges achieved by appropriate therapy.     

Beneficial Circulatory Support by Left Heart Bypass with a Centrifugal (BioMedicus) Pump for Aneurysms of the Descending Thoracic Aorta

Abstract: A comparative study between left heart bypass with a centrifugal (BioMedicus) pump and with a temporary external shunt was performed to assess the efficacy of distal organ perfusion in the surgical treatment of 31 patients with aneurysm of the descending thoracic aorta. Eighteen patients were supported with a centrifugal pump, and the remaining 13 were supported by temporary shunt with either a Gott shunt or a Dacron graft. Heparinless bypass with a centrifugal pump provided a significant decrease of intraoperative blood loss and blood transfusion by the combined application of Cell-Saver. The pressure difference between upper and lower extremities decreased (p < 0.05) in the centrifugal pump group even with aortic cross-clamping, and the urine output increased during operation. Among 13 patients supported with the temporary shunt, 3 had postoperative renal failure, and 2 died of it. All patients with a centrifugal pump survived without any complications. It could be concluded that the left heart bypass with a centrifugal (BioMedicus) pump was safe and was favorable for support of the distal circulation during aortic cross-clamping and to prevent ischemic complications such as renal failure and spinal cord injury.     

Aneurysms of the descending aorta: surgical experience with three methods of adjunct procedures

Thirteen patients were surgically treated for the repair of aneurysms of the descending aorta, using three different types of adjunct procedures--an external temporary bypass with a vascular prosthesis, a tridodecylmethylammonium chloride (TDMAC) or a partial cardiopulmonary bypass. There was no operative death, though one patient died 73 days following surgery. Significant intraoperative morbidity occurred in 3 patients: one had ventricular fibrillation and the other two massive hemorrhages. There was no instance of paraplegia or renal failure. The only significant complication that developed was pulmonary insufficiency in two patients with a pump bypass. The mean operative time and the mean aortic occlusion time in patients with the TDMAC shunt were shorter than the times in patients with the vascular prosthetic shunt or the pump bypass. TDMAC shunt required no special equipment and cannulation was simpler and safer.     

Successful resection of an aortic arch aneurysm using a temporary trifurcation bypass graft

Resection of a syphilitic aortic arch aneurysm in a 62-yearold woman was accomplished using a trifurcation temporary bypass system. The bifurcation graft was sutured end-to-side to the ascending thoracic aorta, to the brachiocephalic trunk and to the left common carotid artery, respectively. The attached third limb end was anastomosed end-to-side to the infrarenal abdominal aorta. This technique enabled a larger shunt into the abdominal aorta. Occlusion of the iliac arteries proved to be effective in coping with hypotension while attending to the bypass and the volume replacement. The post-operative recovery was uneventful and the patient has remained well after 43 months.     

Tetralogy of Fallot with Coexisting Type II Aortopulmonary Window

An infant had a coexisting tetralogy of Fallot and type II aortopulmonary window between the ascending aorta and the right pulmonary artery in which the communication acted as a palliative systemic-pulmonary shunt. Surgical repair is described, and the appropriate literature is reviewed.     

Combined repair of adult coarctation of the aorta and aortic valvular stenosis

A 57-year-old man with a high-grade aortic stenosis and aortic coarctation was treated with concomitant valve replacement and insertion of a conduit from the ascending aorta to the retrocardiac descending aorta via the left pleura. Because heart failure has been reported shortly after cardiopulmonary bypass using this technique, the conduit was initially clamped until the postrepair haemodynamics was stable. Computed tomography after 14 months verified patency of the shunt.     

Repair of lesions of the descending thoracic aorta with the TDMAC-heparin shunt

Utilizing a heparinized tridodecylmethylammonium chloride (TDMAC) shunt makes it possible to treat various surgical diseases of the descending thoracic aorta without cardiopulmonary bypass. Since the initial report by Gott and associates on the use of the heparinized shunt, few subsequent clinical trials have appeared in the literature. Six patients with Type III dissecting thoracic aneurysm, acquired and congenital coarctation of the aorta, saccular arteriosclerotic aneurysm, and transection of the descending thoracic aorta were operated upon by means of this technique. Only one patient had more than 500 ml. of chest tube drainage in the first 8 hours postoperatively. There were no instances of paraplegia, renal failure, or death. This technique is also recommended for repair of innominate artery aneurysms, endarterectomy of the innominate or subclavian artery, arch aneurysm, penetrating injuries of the thoracic aorta, and proximal abdominal aneurysms. Surgical indications, operative management, and postoperative follow-up are discussed.     

Clinical study of centrifugal pump bypass as an auxiliary technique for surgical treatment of descending thoracic aorta

Left heart bypass or arterial bypass using a centrifugal pump (Bio-pump bypass) with a H-PSD shunt tube was performed as an auxiliary technique for the treatment of descending thoracic aorta in 13 cases. Hemodynamic differences during aortic clamp were compared between cases using Bio-pump bypass and 4 cases of axillo-femoral temporary bypass which were carried out in the first term. Furthermore, in Bio-pump bypass cases, the bypass route was investigated from the point of view of operative complications in relation to bypass technique. Peripheral blood pressure and urinary output during aortic clamp were significantly increased in the Bio-pump bypass group. Those results indicated that the Bio-pump bypass was useful as an auxiliary technique especially for high risk patients with low renal function. In particular, left heart bypass was a beneficial technique which was not affected by modality or region of disorder in the descending thoracic aorta. However, this technique should be selected carefully for patients with cardiac disease, for instance severe left ventricular hypertrophy, because two cases of operative complications consisting of pericardial effusion related to the bypass technique were experienced in this study.     

A New Approach to Pseudoaneurysm of the Ascending Aorta

A pseudoaneurysm of the ascending aorta was repaired successfully with Fogarty balloon occlusion and bypass employing cardiotomy suckers. This previously unreported application of a basic vascular technique can simplify management in selected patients.     

The results of bypass with the BioPump in the surgery of traumatic rupture of the thoracic aorta without heparin

In surgery of the traumatic rupture of descending thoracic aorta, external shunt without systemic heparinization is commonly employed to avoid the bleeding of other injured organs as well as the ischemic injury of spinal cord. However, it provides no means of controlling the flow. We employed the BioPump without heparinization in 2 cases of traumatic rupture of descending thoracic aorta and additional 2 cases of aneurysm of thoracic aorta. Significant platelet loss occurred immediately after operation, however, there was no postoperative evidence of the organ failures due to microembolization. Heparinless bypass with the BioPump is considered to be safe and simple as an adjunct means in surgery of the traumatic rupture of thoracic aorta.     

Atypical Proximal Coarctation of the Aorta: Reconstruction by Means of a Heparin-Coated Temporary Shunt Bypass

Coarctation of the aorta may be found proximal to or involving the left subclavian artery. In this situation, adequate collateral may not be present, making aortic occlusion unduly dangerous. Simple and effective bypass protection can be achieved with a heparin-coated temporary shunt as illustrated in two patients described in this report.