1980: descending aortic aneurysmectomy without adjuncts to avoid ischemia. 1993 update

RETRACTED: Anesthesic and surgical guideline for the treatment of the thoraco-abdominal aorta. Consensus Document of the Spanish Societies of Anesthesia and Cardiovascular Surgery

Este artículo ha sido retirado por indicación del Editor Jefe de la revista, después de constatar que parte de su contenido había sido plagiado, sin mencionar la fuente original: European Heart Journal (2014) 35, 2873 926.: https://academic.oup.com/eurheartj/article/35/41/2873/407693#89325738 El autor de correspondencia ha sido informado de la decisión y está de acuerdo con la retirada del artículo. El Comité Editorial lamenta las molestias que esta decisión pueda ocasionar. Puede consultar la política de Elsevier sobre la retirada de artículos en https://www.elsevier.com/about/our-business/policies/article-withdrawal

Thoracoabdominal Aortic Aneurysm Repair: What Should the Anaesthetist Know?

The surgical repair of descending thoracic aortic (DTA) and thoracoabdominal aortic aneurysms (TAAAs) presents one of the greatest challenges for anaesthesiologists. The challenge comes from the fine balance of complex medical issues in the setting of altered physiology that occurs during the perioperative period. Patients presenting for TAAA repair usually have multiple pre-existing comorbid conditions involving their cardiac, pulmonary and renal systems; and aneurysm repair poses a direct and immediate threat to these systems in addition to that to the gastrointestinal and neurologic systems. Operative mortality in thoracoabdominal aortic surgery is quite high to the extent of 5%-12% with a 5-year survival rate of 70%-79% for DTA aneurysm and 59% for thoracoabdominal aortic aneurysm surgeries. Complex haemodynamic changes associated with the clamping and declamping of aorta requires thorough knowledge and expertise for the management of TAAA. We present a brief review on the anaesthetic management and possible complications that anaesthetists should be aware of during TAAA repair.

Hassan Najafi, May 22, 1930-May 20, 2017

Dr Hassan Najafi, an immigrant from Iran who became the 18th president of The Society of Thoracic Surgeons, died on May 20, 2017. He had also served as chair of the American Board of Thoracic Surgery and the Residency Review Committee for Thoracic Surgery, and was a founding member and first president of the Thoracic Surgery Directors Association. A superb technical surgeon, educator, and investigator, Dr Najafi led the Department of Cardiovascular and Thoracic Surgery at Rush University Medical Center for 25 years. Refined and charismatic, he was wholly devoted to his patients, family, trainees, colleagues, and our profession.

Management of Thoracic Aneurysm

A review of the literature on the management of thoracic aneurysm is presented. These patients have various comorbid conditions and need thorough work-ups. Aneurysms can be classified according to shapes and locations. Various methods to maintain hemodynamic stability with adequate endorgan perfusion are presented. The success of the operation depends upon preoperative anticipation and preparation for adequate organ perfusion and hemodynamic stability along with good communication between the anesthesiologist and the surgical team.

Descending Thoracic Aortic Aneurysm Repair With the Aid of Partial Cardiopulmonary Bypass: Heparin-coated Circuits Versus Nonheparin-coated Circuits

BACKGROUND

We have performed descending thoracic aortic aneurysm repairs with partial cardiopulmonary bypass, including heparin-coated circuits. The aim of this study was to evaluate (i) the impact of partial cardiopulmonary bypass on distal organ function and surgical outcomes; and (ii) the effectiveness of using heparin-coated circuits for preventing bleeding complications.

METHODS

From July 1980 to June 2004, 309 patients underwent descending thoracic aortic aneurysm repairs using partial cardiopulmonary bypass. Their mean age was 61 years (range 19-81 years). One hundred of the 309 patients underwent repair of descending thoracic aortic aneurysm with heparin-coated circuits. Blood data for renal and hepatic function were collected on the day before the operation and postoperative days.

RESULTS

The in-hospital mortality was 15%. Distal organ dysfunction included spinal cord dysfunction in 2 patients (0.7%) and renal failure necessitating hemodialysis in 15 patients (5%, 15/297: excluded 12 dialysis patients). Multivariate analyses showed that preoperative hemodialysis and emergency operation were risk factors for operative mortality and that emergency operation was a risk factor for requiring hemodialysis. Renal and hepatic function normalized by 2 weeks after surgery. There were no significant differences between the heparin-coated group and nonheparin-coated group in amounts of packed red cells, fresh frozen plasma, and platelets transfused during the procedures.

CONCLUSIONS

Our data showed that partial cardiopulmonary bypass is a safe and effective method for distal perfusion. Using this technique, descending thoracic aortic aneurysm repair can be performed with acceptable mortality and morbidity. However, the superiority of heparin-coated circuits over nonheparin-coated ones was not proved.

Prevention and detection of spinal cord injury during thoracic and thoracoabdominal aortic repairs

BACKGROUND

Spinal cord injury is a most dreaded and unpredictable complication. In this study, based on our experimental results in dogs and early clinical results, we reviewed the incidence of paraplegia and the detection of spinal cord injury.

METHODS

Eighty-two patients who underwent elective surgical repair of the descending thoracic and thoracoabdominal aorta over 17 years were subjects for this study. Sixty-two patients were male and 20 were female. Their mean age was 61.6 years (range, 17 to 81 years). Monitoring somatosensory evoked potentials (SEP) and measurement of mean distal aortic pressure and cerebrospinal fluid pressure were performed perioperatively.

RESULTS

Sixty patients had no ischemic change in SEP. In 17 patients with significant ischemic changes of SEP, SEP recovered by increasing spinal cord perfusion pressure to more than 40 mm Hg. Two patients with complete loss of SEP experienced paraplegia. One patient had delayed paraplegia.

CONCLUSIONS

These results strongly suggest that SEP, mean distal aortic pressure, cerebrospinal fluid pressure should be monitored during aortic cross-clamping. Maintaining spinal cord perfusion pressure at more than 40 mm Hg by increasing mean distal aortic pressure or withdrawal of cerebrospinal fluid is valuable for preventing paraplegia.

Effects of hypothermia on blood flow and neural activity in rabbit spinal cord during postischemic reperfusion

The effects of hypothermia on blood flow and neural activity were investigated in rabbit spinal cord during the acute phase of ischemia/reperfusion. Rabbits were exposed to ischemia for 10 or 40 min by occluding the abdominal aorta, using a balloon catheter. The body temperature was maintained either at 38 degrees C (normothermia) or 34 degrees C (hypothermia). Hyperperfusion was observed within 10 min after the cessation of ischemia in all rabbits exposed to ischemia. The magnitude of hyperperfusion in spinal cord blood flow (SCBF) was not significantly different between the 10 and 40 min ischemia rabbits, but the time for 50% recovery from the hyperperfusion was longer in the 40 min ischemia group (26.1 +/- 2.5 min) than in the 10 min group (15.1 +/- 2.1 min). The amplitude of evoked spinal cord potential decreased during ischemia and recovered to the baseline level during 8 h of reperfusion in the 10 min ischemia group. However, in the 40 min ischemia group, the amplitude was 40 +/- 8% of the baseline value after 8 h of reperfusion. Hypothermia prevented the delay of recovery from hyperperfusion and the reduction of evoked spinal cord potential. These results suggest that hypothermia plays a beneficial role in protecting tissue injury in the acute phase of ischemia/reperfusion in the spinal cord by shortening the time for recovery from postischemic hyperperfusion.

Reduction of neurologic injury after high-risk thoracoabdominal aortic operation

BACKGROUND

Of all aortic operations, thoracoabdominal aortic repairs have the highest risk of spinal cord neurologic injury, manifest by lower limb paraplegia or paraparesis. Cerebrospinal fluid drainage combined with intrathecal papaverine (CSFDr + IP) may reduce the risk and severity of neurologic injury. The objective of this study was to evaluate the effect of CSFDr + IP to prevent neurologic injury after high-risk thoracoabdominal aneurysm repairs.

METHODS

We screened 64 patients before operation with descending thoracic or thoracoabdominal aneurysms for possible inclusion in a prospective, randomized study. Thirty-three patients with high-risk type I and II thoracoabdominal aneurysms met inclusion criteria and 17 were randomly assigned to CSFDr + IP and 16 to the control group. The study was terminated early after interim analysis revealed a significant difference.

RESULTS

Of 64 patients screened, 2 patients died after operation (3.1%, 2/64); both were in the randomized study (6%, 2/33), and neither had a neurologic injury. Neurologic injury developed in 2 CSFDr + IP patients and 7 control patients (p = 0.0392). Control patients also had lower postoperative motor strength scores (p = 0.0340). On multivariate analysis, risk factors for neurologic injury included (p < 0.05) longer cross-clamp time, failure to actively cool with bypass, and postoperative hypotension, whereas CSFDr + IP was protective. Logistic regression showed that CSFDr + IP and active cooling significantly reduced the risk of injury and that the two combined modalities were additive. Of 64 patients screened, only 2 (3%) had a permanent neurologic deficit preventing ambulation.

CONCLUSIONS

For high-risk thoracoabdominal aneurysms, CSFDr + IP was effective in reducing the incidence and severity of neurologic injury. Active cooling may be further additive to CSFDr + IP protection, although this needs to be confirmed in a larger study.

Spinal cord protection during surgical procedures on the descending thoracic and thoracoabdominal aorta: a critical overview

During the past three decades, significant advances have been made in the surgical treatment of the diseases affecting the aorta. Despite these important advances, paraplegia remains a devastating complication of the surgical procedures on the thoracic and thoracoabdominal aorta. Paraparesis and paraplegia occur as a direct result of the interruption of blood flow to the spinal cord during the surgical procedures. A number of techniques have been advocated for the prevention of spinal cord ischemic injury. This article critically reviews our current understanding of the extent of this problem, the mechanism of injury, and the methods that have been devised to reduce the frequency of paraplegia following surgical procedures on the descending aorta.

Our distal aortic perfusion system in descending thoracic and thoracoabdominal aortic aneurysm repairs

We have used heparin-bonded partial cardiopulmonary bypass to support distal aortic circulation during aortic cross-clamping. However, there were no cardiotomy reservoirs with fully reliable thromboresistance. To resolve this problem, a short-acting anticoagulant (nafamostat mesilate) was added into a cardiotomy reservoir. The present study was designed to evaluate the efficacy of our distal perfusion system. From May 1995 through the end of May 1996, 27 patients underwent descending thoracic and thoracoabdominal aortic aneurysm repairs with this adjunct, 4 being excluded from the experiment. Twenty patients who had undergone conventional partial cardiopulmonary bypass were defined as the control group. There were no significant differences between the 2 groups in the morbidity, mortality, gas transfer, or transfusion requirements despite the fact that more complicated surgical procedures (shown by a two-fold increase in the prevalence of reoperation) were required in the group that had received the current distal perfusion adjunct the heparin-bonded group. In conclusion, our perfusion system is very effective for descending thoracic and thoracoabdominal aortic aneurysm repairs.

Improvement in results of repair of type IV thoracoabdominal aortic aneurysms

PURPOSE

Although management of extensive type I and II thoracoabdominal aortic aneurysms (TAA) remains a formidable challenge, results of repair of TAA originating in the distal thoracic aorta (type IV) appear to have improved significantly. To quantitate this perceived improvement, the following retrospective study was undertaken to examine the results of type IV TAA repair at the Brigham & Women's Hospital over the past 18-year period.

METHODS

From July 1977 to September 1994, nonruptured atherosclerotic type IV TAAs were repaired in 58 patients. The mean age was 70 years, and associated risk factors included smoking (91%), hypertension (86%), coronary artery disease (52%), and previous aortic surgery (38%). Mean follow-up was 2.4 years (median 2 years).

RESULTS

Overall 30-day mortality was 5.3% (two deaths). Morbidity included stroke (3.5%), paraplegia (1.8%), permanent paraparesis (1.8%), myocardial infarction (7%), pneumonia (8.8%), gastrointestinal bleeding (11%), intestinal ischemia (5.3%), wound infection (7.0%), peripheral ischemia (5.3%), in-hospital dialysis (8.8%), and permanent dialysis (1.9%). Overall 5-year survival was 50%. With univariate analysis, survival was positively correlated with more recent year of operation (p = 0.002), smaller volume of intraoperative blood transfusion (p = 0.02), decreased supraceliac ischemia time (p = 0.04), and the use of the retroperitoneal approach (p = 0.09). Multiple regression analysis revealed that the year of operation was the only independent predictor of survival (p = 0.003). Subgroup analysis of patients who underwent operation between 1977 and 1987 (n = 13) and 1988 and 1994 (n = 45) revealed statistically significant improvements in length of hospital stay (46 +/- 12 vs 21 +/- 4 days, p = 0.02), postoperative dysrhythmia (50% vs 16%, p = 0.03), postoperative maximum serum glutamic oxaloacetic-transaminase (516 +/- 234 vs 319 +/- 139 mg%, p = 0.04), incidence of hemorrhage requiring reexploration (33% vs 0%, p = 0.002), 30-day mortality (23% vs 0%, p = 0.009), and in-hospital mortality (39% vs 2.2%, p = 0.002).

CONCLUSIONS

The modern mortality, morbidity, and survival of surgical repair of type IV TAA in our institution approaches that of infrarenal abdominal aortic aneurysm.

Prevention of spinal cord injury after repair of the thoracic or thoracoabdominal aorta

Spinal cord injury occurring as the result of surgical repair of thoracic and thoracoabdominal aortic disease remains a devastating complication. The incidence of postoperative neurologic deficits varies from 4% to 38%. Factors associated with a greater risk for injury include the presence of dissection or extensive thoracoabdominal disease, and a prolonged cross-clamp time. Spinal cord ischemia initiates a deleterious cascade of biochemical events that ultimately result in an increased intracellular calcium concentration. Calcium-activated proteases, lipases, and nucleases mediate the processes that cause cell injury. The accumulation of oxygen-derived free radicals and the occurrence of hyperemia during reperfusion are also contributing causes of spinal cord injury. Increasing the spinal cord blood flow with shunts, oxygenated bypass circuits, cerebrospinal fluid drainage, the intrathecal administration of vasodilators, and the reattachment of intercostal arteries has been tried in an effort to increase spinal cord perfusion. Pharmacologically based measures to prevent spinal cord injury have been pursued, and these have consisted of hypothermia, anesthetic agents, calcium channel blockers, free radical scavengers, and immune system modulation. However, no single technique has proved to be consistently effective in preventing ischemia-induced spinal cord injury.

Graft replacement of the descending thoracic aorta: results of "open" distal anastomosis

With the advent of rapid autotransfusion, we began to repair aneurysms of the descending thoracic and thoracoabdominal aorta by using an "open" technique, in which a single cross-clamp is placed proximal to the aneurysm to exsanguinate the lower body. To determine whether open distal anastomosis effectively protects against spinal cord injury, we studied 71 consecutive patients (50 men, 21 women) who underwent this procedure beginning in April 1989. The patients ranged in age from 31 to 83 years (mean, 63.3 years). Most patients were hypertensive (n = 61; 86%) and symptomatic (n = 54; 76%). Most had been diagnosed with medial degeneration (n = 45; 63.4%) or aortic dissection (n = 16; 22.5%). Five patients (7.0%) were admitted with aortic rupture. We replaced the entire descending thoracic aorta in 31 (43.7%), the thoracoabdominal aorta in 21 (29.6%), and a segment of the descending thoracic aorta in 19 (26.7%). The average distal ischemic time was 22.4 minutes (range, 11 to 42 minutes). The amount of blood returned through the autotransfusion device averaged 2,099 mL. Eight patients (11.3%) died within 30 days (multiple organ failure, 3; hemorrhage, 2; coexisting ischemic heart disease, 3). Spinal cord dysfunction occurred in 6 patients (8.5%) (lower extremity paraparesis, 4; paraplegia, 2). Renal insufficiency requiring dialysis occurred in 4 patients (5.6%). We believe that the low incidence of spinal cord injury and renal insufficiency in this series may have resulted from the free draining of the intercostal and lumbar arteries during aortic occlusion, which decreases cerebrospinal fluid and central venous pressures.(ABSTRACT TRUNCATED AT 250 WORDS)