Cardiac function is a risk factor for paralysis in thoracoabdominal aortic replacement

PURPOSE: We studied factors that influence paralysis risk, renal function, and mortality in thoracoabdominal aortic replacement. METHODS: We prospectively collected preoperative demographic and intraoperative physiologic data and used univariate and multivariate analyses to correlate this data with risk factors for paralysis. A mathematical model of paraplegia risk was used to study the efficacy of paraplegia reduction strategies. We analyzed preoperative and operative factors for paralysis risk, renal function, and mortality for 217 consecutive patients surgically treated from 1984 through 1996 for 176 thoracoabdominal and 41 thoracic aneurysms at the University of Wisconsin Hospital and Clinics. No patient had intercostal reimplantation or assisted circulation. One hundred fifty patients (group A) received cerebrospinal fluid drainage (CSFD) and low-dose naloxone (1 microg/kg/hour) as adjuncts to reduce the risk of paralysis. Sixty-seven patients (group B) did not receive CSFD and naloxone. RESULTS: Seventeen deficits occurred in 205 surviving patients: 5 of the 147 in group A (expected deficits = 31) and 12 of the 58 in group B (expected deficits = 13) (p < 0.001). In a multivariate logistic regression model, acute presentation, Crawford type 2 aneurysm, group B membership, and a decrease in cardiac index with aortic occlusion remained significant risk factors for deficit (p < 0.0001). By odds ratio analysis, group A patients had 1/40th the risk of paralysis of group B. The only significant predictor of postoperative renal function was the preoperative creatinine level (p < 0.0001); renal revascularization significantly improved renal function. The mortality rate was 1.6% (2) for patients undergoing elective treatment and 21% (19) for patients who had acute presentations. Acute presentation, age, and the preoperative creatinine level were found to be significant factors for operative mortality in a logistic regression model (p < 0.001) and defined a group at high risk for death. CONCLUSIONS: CSFD and low-dose naloxone significantly reduce the paralysis risk associated with thoracoabdominal aortic replacement. A decrease in the cardiac index with aortic occlusion is a previously unreported variable that defines a subset of patients at higher risk for paralysis.     

Surgical treatment of thoracoabdominal aortic aneurysms]

Between February, 1981, and April, 1989, 20 patients underwent surgical treatment of thoracoabdominal aortic aneurysms. Most of the patients were operated under temporary external bypass. For Group I and III aneurysms without reconstruction of renal arteries, a modified Crawford's graft inclusion technique was employed to shorten abdominal visceral ischemic time. This modification consists of (1) using adjuncts to perfuse the distal aorta during aortic clamp, (2) starting the first anasistomosis from the distal end of the graft, and (3) shifting the distal aortic clamp on the graft after completing the anastomosis in order to restore abdominal visceral circulation as soon as possible. For Group III and IV aneurysms with reconstruction of renal arteries as well as celiac and superior mesenteric arteries, a modified DeBakey's procedure was employed. This modification consists of (1) using the spiral opening method, (2) doing end-to-end anastomosis at the proximal aortic site, and (3) maintaining the circulation of abdominal organs and spinal cord by using adjuncts during the anastomosis of the proximal end. There were one operative death and two hospital deaths. Paraplegia developed in two cases, one of which was a ruptured case. Renal dysfunction was not found in any case. The survivors were followed from 5 to 103 months, and there was no late death. The results suggest that our modified procedures for thoracoabdominal aortic aneurysms are useful and reliable ones.     

Renal failure after thoracoabdominal aortic surgery

PURPOSE: Renal failure remains a common and morbid complication after complex aortic surgery. This study was performed to identify perioperative factors that contribute to postoperative renal failure. METHODS: The perioperative outcomes of 183 patients who underwent thoracoabdominal aortic surgery with supraceliac clamping were reviewed. During the interval from Jan. 1987 to Nov. 1996, thoracoabdominal aneurysm repair was performed in 154 patients (type I, 49 patients [27%]; type II, 21 patients [11.5%]; type III, 55 patients [30%]; type IV, 29 patients [16%]), suprarenal abdominal aortic aneurysm repair in 17 patients (9%), and visceral/renal revascularization procedures in 12 patients (6.5%). Intraoperative management included thoracoabdominal aortic exposure and clamp-and-sew technique with renal artery cold perfusion whenever the renal arteries were accessible (79% of cases). RESULTS: Relevant clinical features included preoperative hypertension (85%), diabetes mellitus (8%), single functioning kidney (10%), recent intravenous contrast injection (34%), renal insufficiency (creatinine level greater than 1.5 mg/dl; 24%), and emergent operation (19%). Acute renal failure, defined as both a doubling of serum creatinine level and an absolute value greater than 3.0 mg/dl, occurred in 21 patients (11.5%), of whom five required hemodialysis (2.7%). Variables associated with this complication included a preoperative creatinine level greater than 1.5 mg/dl (p = 0.004) and a total cross-clamp time greater than 100 minutes (p = 0.035). The operative mortality risk (within 30 days; 8%) was significantly increased with renal failure (odds ratio, 9.2; 95% confidence interval, 2.6 to 33; p < 0.005). CONCLUSIONS: Renal failure, although uncommon in contemporary practice, greatly increases the risk of early death after thoracoabdominal aortic surgery. The overall incidence of renal failure and dialysis requirement in the present series compare favorably with those reported using other operative techniques, specifically partial left heart bypass and distal aortic perfusion. These data suggest that patients who have preoperative renal insufficiency are prone to postoperative renal failure. Furthermore, regional hypothermic perfusion and minimal clamp times are important elements in the prevention of renal failure after thoracoabdominal aortic surgery.     

Surgical treatment of thoracoabdominal aortic aneurysm

Graft replacement for thoracoabdomital aortic aneurysm was performed in 8 patients between 1982 and 1989. Five patients in our series underwent reattachment of the branch vessels to openings made in the graft. Partial bypass or external shunt was used in 6 patients during aortic cross-clamping. Selective blood perfusion to the branch vessels was performed in 5 patients intraoperatively. Neither hospital death nor postoperative paraplegia was found in our series. One patient without selective perfusion of abdominal branch vessels during reattachment to the graft developed an acute jaundice postoperatively, but 4 of the 5 patients receiving selective perfusion of branch vessels developed no complication related to abdominal ischemia. These results suggest that intraoperative blood perfusion of aortic branch might be useful for prevention of anoxic complication of the abdominal organs after surgery of thoracoabdominal aortic aneurysm.     

Deep hypothermic arrest and left thoracotomy for repair of difficult thoracic aneurysms

Seven patients with complex thoracic aortic aneurysms were operated on using profound hypothermia and circulatory arrest through a left thoracotomy. Three patients had false aneurysms, 2 had large aneurysms precluding access for proximal control, 1 patient had had previous hemiarch replacement, and 1 patient had a thoracoabdominal aneurysm. All patients were cooled on partial cardiopulmonary bypass until the electroencephalogram was isoelectric (approximately 15 degrees C rectal temperature). Circulatory arrest times ranged from 7 to 56 minutes (median, 34 minutes). There was one death due to cardiac failure, and paraplegia developed in 1 patient. The 6 survivors are otherwise well at a median of 12 months postoperatively. Hypothermia and circulatory arrest is an invaluable technique for the treatment of complex aortic aneurysms requiring left thoracotomy for resection. The techniques employed are described and the indications for their use are discussed.     

Identification of 1,4-dihydropyridine binding domains within the primary structure of the alpha 1 subunit of the skeletal muscle L-type calcium channel

Damage to the spinal cord in course of the treatment of diseases of the infrarenal aorta is a rare but calamitous complication. The reported incidence is about 0.2%. The neurological loss is usually complete flaccid paraplegia with high mortality and rare full or partial recovery. Between 1980 and 1991, 1070 reconstructive procedures of the infrarenal aorta were performed: 821 due to aneurysm (316 elective procedures [mortality 1.6%] and 505 emergency procedures [mortality 24.5%]) and 249 due to aorto-iliac occlusive disease. Damage to the spinal cord occurred in 2 patients (2/1070, 0.19%). One patient had incomplete paraparesis following repair of an unruptured abdominal aortic aneurysm with gradual return of all neurological symptoms to normal. The second patient developed complete paraplegia following repair of a ruptured infrarenal aneurysm. There war no recovery of the symptoms. The patient died from septicaemia 4 months later.     

Current status of the use of retroperitoneal approach for reconstructions of the aorta and its branches

OBJECTIVE: The objective of this article is to determine whether retroperitoneal approach for aortic surgery has certain physiologic, technical advantages. SUMMARY BACKGROUND DATA: The retroperitoneal approach for abdominal aortic reconstruction classically had been reserved for select patients with either high-risk comorbid disease or specific anatomic problems that preclude the transabdominal approach. With increasing appreciation of the physiologic, anatomic, and technical advantages of the extended posterolateral retroperitoneal approach, the authors have expanded its use for repair of all types of aortic visceral and renal artery disease as well as ruptured abdominal aortic aneurysm and infected aortic grafts. METHODS: From January 1981 to September 1995, 2340 retroperitoneal aortoiliac reconstructions were performed in 2243 patients. Aortic reconstructions accounted for 1756 cases: 1109 for elective abdominal aortic aneurysms, 210 for ruptured and symptomatic aortic aneurysms, 399 for occlusive disease, 18 for infected aortic grafts, and 20 for other indications. Iliofemoral disease was the indication for 584 procedures. As experience was gained, this approach also was used for 417 renal and 50 celiac and superior mesenteric artery reconstructions. RESULTS: The mean age was 67 years with 1590 men and 653 women. Overall mortality was 5.2% for all aortic cases: 2.4% for elective, 12.6% for symptomatic, and 29.0% for ruptured aortic aneurysms. Major complications occurred in 12.5% of the elective procedures and in 38.3% of emergency procedures. Over the past 5 years, the average length of hospital for uncomplicated elective abdominal aortic aneurysms was 6.1 days, intensive care unit stay was 0.7 day, and diet was resumed by postoperative day 1. Five-year graft patency was 99% for aneurysms and 95% for occlusive disease. CONCLUSIONS: The retroperitoneal approach offers certain physiologic advantages associated with minimal disturbance of gastrointestinal and respiratory function, thereby reducing the length of intensive care unit and hospital stay. In addition, its technical advantages and flexibility facilitates visceral and juxtarenal aortic reconstructions without the need for thoracotomy.     

High-speed, three-dimensional kinematic analysis of the normal wrist

PURPOSE: To identify the predictive risk factors for rupture of thoracoabdominal aortic aneurysms (TAA). METHODS: Thirty-one patients with TAA who did not have the indications for surgical repair of the aneurysm were selected. Inclusion criteria were maximum diameter less than 60 mm, refusal of surgical treatment, and high surgical risk. The selected patients participated in a prospective follow-up study for a median period of 47 months and underwent at least two thoracoabdominal computed tomographic scans a year to measure transverse and anteroposterior diameters. Identification of the predictive factors associated with rupture was undertaken with multivariate analysis by means of Cox regression model. RESULTS: During the study period five patients underwent elective repair, six died of unrelated causes, nine had aneurysms that ruptured (all with diameters greater than 50 mm), and 11 reached the end of the study without rupture or surgical management. Initial anteroposterior diameter and annual growth rate of the anteroposterior diameter were the variables associated with rupture of the TAA according to the multivariate statistical analysis by means of Cox regression model. CONCLUSION: We recommend elective repair for a fit patient with asymptomatic TAA with an initial anteroposterior diameter of 50 mm only when there is an annual growth rate of at least 10 mm. Patients with similar diameters but with smaller annual growth rates should be treated conservatively and undergo thoracoabdominal computed tomography every 6 months. Patients with an initial anteroposterior diameter of 60 mm and an annual growth rate of 6 mm should undergo surgical treatment. These guidelines for elective repair of TAA are based on the results of a relatively small series and have to be carefully individualized for each patient.     

Stent-graft placement procedures for descending thoracic aortic aneurysms

Descending thoracic aortic aneurysms most often are caused by arteriosclerosis and appear most frequently in elderly males. These patients often are asymptomatic, but they may experience symptoms related to compression of adjacent thoracic structures, or they may present for treatment when their-aneurysms rupture. Open surgical resections and repairs of descending thoracic aortic aneurysms are associated with bleeding, paraplegia, strokes, renal insufficiency, and the need for prolonged ventilatory support in the postoperative period. At Stanford (Calif) University Hospital, surgeons are placing endovascular stent-grafts in patients with descending thoracic aortic aneurysms who meet specific anatomic selection criteria. This new treatment modality provides patients with a less invasive, less hazardous, and potentially less expensive alternative to open surgical resection and repair procedures. Preoperative teaching and skilled perioperative nursing care are essential for positive patient outcomes with stent-graft treatment of descending thoracic aortic aneurysms.     

Open distal anastomosis or aortic balloon occlusion technique during complete aortic arch replacement

The technique of open distal anastomosis or application of aortic balloon occlusion catheter designed to occlude the descending thoracic aorta have been used in 33 and 19 patients, respectively, to control bleeding during the procedure of distal anastomosis for complete aortic arch replacement with a prosthetic graft. These two techniques allowed us a simple approach to the lesion and the avoidance of clamp injury to the fragile aortic tissue. Open distal anastomosis was applied for 91% patients of operated aortic dissection and all emergent cases, it's duration ranged from 10 to 110 minutes with an average of 58 minutes under 18.2 degrees C of lowest esophageal temperature. On the other hand, aortic occlusion balloon was inserted for mainly true aortic aneurysm patients without an emergency, and helped to maintain the perfusion pressure on a lower part of body around 50 mmHg by the 1550 ml/min in an average of perfusion flow femoral artery under 21.2 degrees C of temperature. The difference of postoperative renal and liver function evaluated by serum enzyme levels of total bilirubin, GOT, GPT, LDH, creatinine and BUN did not reach to statistical significance between the patients using open distal anastomosis and balloon occlusion, however, the incidence of postoperative complication including either renal, liver dysfunction, abdominal problem or paraplegia was significantly higher in the patient group with open distal technique. Either open distal anastomosis or aortic balloon occlusion technique would be appropriately selected according to the patient's characteristics or the condition of aortic disease to be operated.     

Strategies to prevent neurologic deficit based on motor-evoked potentials in type I and II thoracoabdominal aortic aneurysm repair

PURPOSE: Motor-evoked potentials (MEPs) were monitored during thoracoabdominal aortic aneurysm (TAAA) repair to assess spinal cord ischemia and evaluate the subsequent protective strategies to prevent neurologic deficit. METHODS: Between January 1996 and December 1997, 52 consecutive patients with type I (n = 24) and type II (n = 28) TAAA underwent surgery (mean patient age, 60 years; range, 21-78 years). The surgical protocol included left heart bypass, cerebrospinal fluid drainage, and monitoring transcranial myogenic MEPs. When spinal cord ischemia was detected, distal aortic pressure and mean arterial pressure were increased. By means of sequential crossclamping, MEPs were used to identify critical intercostal or lumbar arteries. RESULTS: Reproducible MEPs could be recorded in all patients, and spinal cord ischemia was detected within 2 minutes. During distal aortic perfusion, 14 patients (27%) showed rapid decrease in the amplitude of MEPs to less than 25% of baseline, indicating spinal cord ischemia, which could be corrected by increasing distal aortic pressure. The mean distal aortic pressure to maintain adequate cord perfusion was 66 mm Hg; however, it varied among individuals between 48 and 110 mm Hg. In 24 patients (46%), MEPs disappeared after segmental clamping and returned after reattachment of intercostal arteries. In 9 patients (17%), MEPs disappeared completely, but no intercostal arteries were found. After aortic endarterectomy, 6 or 8 mm Dacron grafts were anastomosed to intercostal arteries, and MEPs returned after reperfusion. Using this aggressive surgical approach based on MEPs, no early or late paraplegia occurred in this series. CONCLUSION: Monitoring of MEPs is an effective technique to assess spinal cord ischemia. Operative strategies based on MEPs prevented neurologic deficits in patients treated for type I and II TAAA.     

Comparison of amyloid deposition in two lines of transgenic mouse that model familial amyloidotic polyneuropathy, type I

Aortic disease frequently requires extended and multiple resections. Occasionally, resection of the entire aorta may be indicated. At our Institution, from 1982 to 1994, 34 patients were operated upon for extended and total simultaneous aortic replacement. In seven patients, the aorta was replaced from valve to bifurcation; in 27, the aortic valve was included. Operations were performed with circulatory arrest under profound hypothermia. As the first step, the aortic valve and ascending aorta are replaced and the coronary arteries are reconnected, following which the aortic arch is reconstructed. Meanwhile, a second surgical team proceeds to open the thoracoabdominal aorta and tie up the intercostal orifices. If circulatory arrest is likely to exceed 60 minutes, the aortic graft is clamped and upper body perfusion (1000 cc/min) is begun. Finally, the thoracoabdominal aorta is fully replaced. Cardiopulmonary bypass (CPB) with rewarming is resumed only after the operation has been completed. Thirty-four patients survived operation; five died within 1 month for an overall mortality of 14.7%. No mortality occurred in the most recent nine operations. No permanent spinal neurological deficits occurred. Total simultaneous aortic replacement for treatment of extended aortic disease may be reasonable using our approach.     

Pressure-guided method for identification of the epidural space in children

Total aortic replacement is preferably performed by staged operations, and reports of a simultaneous operation are few. In these reports, both a median sternotomy and a thoracoabdominal incision are employed. We report a patient who successfully underwent simultaneous total aortic replacement without a sternotomy incision. The technique and the feasibility of the operation are discussed.     

Abdominal and thoracoabdominal aortic aneurysm

Most abdominal aortic aneurysms (AAA) and thoracoabdominal aortic aneurysms (TAAA) are asymptomatic and are found on physical exam or incidentally during radiological studies for other indications. These aneurysms are repaired primarily because their risk of rupture increases geometrically as the size exceeds 5 cm. The potential morbidity of intraoperative visceral and spinal ischemia involved with TAAA repair may be reduced with various adjunctive maneuvers.     

Severe muscle weakness secondary to paraneoplastic hypophosphatemia in neuroblastoma

OBJECTIVES: To evaluate the influence of the use of a bypass on the results of thoracoabdominal aortic aneurysm surgery. METHODS: The results of the repair of 224 thoracoabdominal aortic aneurysms operated upon between 1981 and the end of 1996 were evaluated retrospectively. In 122 cases we used simple cross-clamping (clamp and sew technique) and in 102 cases a left heart bypass (atrio-femoral or aorto-femoral) was the preferred method. Except for the use of cerebrospinal fluid drainage over the last years, the methods of spinal protection were the same in both groups. Renal protection was also identical in both groups. All aneurysms were repaired using the inlay technique. RESULTS: Hospital mortality was 11.2%: 14.7% in cross-clamp group versus 6.8% in the bypass group (p = 0.04). Postoperative dialysis was necessary in 9.8%: 12.7% in the cross-clamp group versus 6.8% in the bypass group (p = 0.108). Paraplegia occurred in 8.4%: 7.4% in the cross-clamp group versus 9.8% in the bypass group (p = 0.517). Using the highly predictive model of Acher, there would have been 33% spinal cord lesions in the bypass group. CONCLUSIONS: Hospital mortality, postoperative dialysis and postoperative spinal cord problems are lowered by the use of a bypass during the repair of thoracoabdominal aortic aneurysms. These results evidence that the use of a bypass is indicated in this complex operation.     

Surgical treatment for aneurysms of the descending aorta using temporary perfusion by a centrifugal pump: clinical analysis of 33 cases

Since 1987, 33 patients have undergone surgery at Kobe University Hospital for aneurysm of the descending aorta using left heart bypass with a heparin-coated centrifugal pump and heparin-coated tubes. Sixteen patients had true aneurysms of the descending thoracic aorta, 7 had thoracoabdominal aneurysms, and 10 had aortic dissection (DeBakey's Type III). Heat exchangers and oxygenators were not included in the bypass circuit in any of the cases. Perfusion time was from 42 to 205 min (average 90 min). Left heart bypass was established with 1 mg/kg of systemic heparinization in 5 cases, 0.5 mg/kg in 5 cases, and 0 mg/kg in 23 cases. There were no complications such as perioperative embolism, acidosis, or hypothermia. During aortic cross-clamping, the arterial pressure of the lower extremity was maintained above 70 mm Hg, but there was no relationship between the distal perfusion pressure and bypass flow. The urine output during left heart bypass was related to the distal perfusion flow by centrifugal pump. Of 23 patients who underwent bypass with less than 40 ml/kg/min of distal perfusion flow, 7 showed transient renal dysfunction postoperatively, and 1 developed postoperative renal failure. The other patients who were bypassed with over 40 ml/kg/min of pump flow stayed in the normal range of renal function. Postoperative paresis occurred in 2 patients, who were also perfused with less than 40 ml/kg/min of bypass flow. It could be concluded that left heart bypass by centrifugal pump is safe and acceptable as a circulatory support in the surgical treatment of aneurysm of the descending aorta.(ABSTRACT TRUNCATED AT 250 WORDS)     

The impact of diaphragm management on prolonged ventilator support after thoracoabdominal aortic repair

PURPOSE: The relationship of the division of the diaphragm during thoracoabdominal aortic repair to prolonged ventilator support has not been studied. The purpose of this study was (1) to determine whether preservation of diaphragm integrity has a significant effect on postoperative ventilator duration and (2) to elucidate other pulmonary risk factors related to thoracoabdominal aortic surgery and to study the relationship of these factors to the intact diaphragm technique. METHODS:Between February 1991 and January 1997, we repaired 397 descending and thoracoabdominal aortic aneurysms. Descending thoracic aneurysms were not included in the study because their repair does not include the diaphragm. A total of 256 patients participated in this study. The diaphragm was divided in 150 patients and left intact in 106 patients. Examined as potential risk factors were patient demographics, history and physical findings, aneurysm extent, urgency of the procedure, acute dissection, cross-clamp time, homologous and autologous blood product consumption, and adjunctive operative techniques. FEV1 also was considered in the 197 patients for whom preoperative spirometry was available. Prolonged mechanical ventilation was defined as ventilator support for >72 hours. Data were analyzed by univariate contingency table and multiple logistic regression methods. RESULTS: Increasing age (odds ratio [OR], 1.02/y; P <.02), current smoking (OR, 2.6; P <.0008), total cross-clamp time (OR, 1.0/min; P <.008), units packed red blood cells transfused (OR, 1.06/unit; P <.008), and division of the diaphragm (OR, 2.03; P <.02) were significant, independent predictors of prolonged ventilation. Sixty-seven percent of patients (71 of 106) whose diaphragms were preserved were extubated in <72 hours compared with 52% of patients (78 of 150) who underwent diaphragm division (OR, 0.53; P <.02). CONCLUSION: Independently of well known pulmonary risk factors, an intact diaphragm during thoracoabdominal aortic repair results in a higher probability of early ventilator weaning.     

Ruptured aortic arch aneurysm with hemorrhagic cardiac tamponade: report a case]

The ruptured thoracic aortic aneurysm has had severely high mortality. A 71-year-old male who suddenly fainted away was admitted to our hospital. He was in shock on arrival. Computed tomography and echo cardiogram demonstrated ruptured aortic arch aneurysm with hemorrhagic cardiac tamponade. Aortic arch replacement was performed using the selective cerebral perfusion under deep hypothermia. The recovery of his consciousness was delayed, and he had right hemiplegia postoperatively, but his state was improved gradually. Finally he complained only slight degree of aphasia, paralysis. An immediate and aggressive emergency operation is a only method to salvage the patient who has ruptured aneurysm of the thoracic aorta.     

Thoracoabdominal aortic repair without using assisted bypass

A 41-year-old man, who had undergone descending aortic repair following rupture of the DeBakey type III aortic dissection, underwent thoracoabdominal aneurysm repair 1 year after the first surgery. The operation was performed by partial-clamping and single crossclamping without using assisted bypass or shunt, in order to minimize bleeding ensuing the re-thoracotomy and dissection between lung and the graft.     

Localization of hepatocyte growth factor and tubulointerstitial lesions in IgA nephropathy

We report a 59-year-old male with abdominal aortic coarctation presented as paraplegia due to spinal hemorrhage caused by the rupture of abnormally dilated spinal artery. In coarctation of aorta, coarctation is usually located in the aortic isthmus which could be the cause of cervical and upper thoracic myelopathy. However, there has been no report of abdominal aortic coarctation with hemorrhagic transverse myelopathy. In this case hemorrhage occurred after surgical treatment and prescribed warfarin may have exaggerated the outcome.