Treatment Of Acute Aortic Dissection Research Articles

Towards safer reoperations: special aspects in aortic dissection☆

Surgical treatment of acute aortic dissection has been largely standardized, but some patients develop late complications that require repeat surgery. The 10-year freedom from proximal and distal reoperation is approximately 70-80%, and the risk of proximal reoperation is approximately 10%. Aggressive resection of the aortic root has not been proven to eliminate the need for proximal reoperation, but it appears reasonable for pre-existent root dilatation. The coronary button technique has resulted in greater freedom from death and reoperation and thus appears advisable. The risk of distal reoperations seems generally lower than that of proximal operations (0-4%). Routine extension of replacement into the total arch in the initial operation is associated with increased risk, and it appears not to decrease the probability of reoperation. Aggressive replacement of the total arch may be justified only for connective tissue disease. The choice of thoracic incision is important for aortic reoperations. A median sternotomy provides excellent exposure to the proximal aorta. A posterolateral thoracotomy allows good exposure for distal arch or descending aorta but may be associated with pain-related pulmonary impairment. A bilateral thoracotomy gives easy access for arch and descending aorta but is associated with the highest degree of respiratory impairment. We use a median sternotomy in most instances and choose a bilateral thoracotomy for complex aortic pathology. A posterolateral thoracotomy seems preferable for most distal arch and/or descending aortic replacements. Since femoral arterial cannulation can contribute to an increased incidence of neurological complication, cannulation of the axillary artery appears advisable. We prefer implantation of a Dacron graft and to cannulate the graft. If the aorta is adjacent to the sternum, the patient is placed on cardiopulmonary bypass (CPB) before repeat sternotomy. The patient is cooled to a nasopharyngeal temperature of 28-30 degrees C and at the time of sternotomy CPB is temporarily interrupted. We have not yet had to use transapical venting. Using these approaches we have been able to maintain a procedure-related mortality of 4%, which is not different from primary operations on an aneurysmatic aorta.

Modified Sandwich Technique for Acute Aortic Dissection

We describe a new method for aortic anastomosis in the repair of acute type A aortic dissection. The anastomosis site is prepared with the adventitial inversion technique, which converts a dissected aorta into a conduit lined with tough adventitia. The end is reinforced with felt strip outside and anastomosed with interrupted everting mattress and running sutures, resulting in complete hemostasis. This modified sandwich technique will likely be useful for the surgical treatment of acute aortic dissection.

Successful surgical treatment for acute aortic dissection in pregnancy with Marfan’s syndrome

A 34-year-old pregnant woman with Marfan's syndrome in the 34th week of gestation was diagnosed with acute DeBakey type I aortic dissection. Immediately after cesarean section, she underwent emergent operation of combined total aortic arch and aortic root replacement using cardiopulmonary bypass, deep hypothermia and antegrade cerebral perfusion. Both maternal and fetal outcomes were good and uneventful. Pregnancy increases the risk of aortic dissection especially for patients with Marfan's syndrome. Moreover it should be noted that cardiac surgery using cardiopulmonary bypass and deep hypothermia generally results in fetal loss. If fetal maturity can be confirmed as in our case, cesarean section should be done before cardiovascular surgery. We describe here a case of successful operation for mother and infant at the 34th week of gestation.

A simple but useful method of screening for mesenteric ischemia secondary to acute aortic dissection

BackgroundIn spite of recent improvements in treatment for acute aortic dissection, mesenteric ischemia secondary to aortic dissection is still challenging. We propose a simple screening method to detect mesenteric ischemia secondary to acute aortic dissection. MethodsFrom 1991 to 2002, 245 patients with acute aortic dissection were admitted to our hospital. Nine (3.7%) of those were complicated with mesenteric ischemia. The clinical records of those 9 patients were retrospectively analyzed. The ratios of the diameter of the superior mesenteric vein (SMV) to that of the superior mesenteric artery (SMA) were calculated in patients with mesenteric ischemia (group M) and in patients without mesenteric ischemia (group C). Blood test data, including results of arterial blood gas analysis, in the 2 groups were also compared. ResultsThe SMV/SMA ratios in groups M and C were 1.16 ± 0.33 and 1.78 ± 0.29, respectively (P=.003). A cutoff value of the SMV/SMA ratio was 1.5 (sensitivity, 88.9%; specificity, 88.9%) with an odds ratio of 64.0. Although there were differences between the 2 groups in glutamate oxaloacetate transaminase, lactate dehydrogenase, creatine phosphate kinase, pH, and lactate values, the measurement of lactate was especially useful (P=.002). ConclusionsThe combination of the SMV/SMA ratio and lactate concentration is a useful screening method to detect mesenteric ischemia secondary to acute aortic dissection.

Aneurysmal degeneration of the aorta after stent-graft repair of acute aortic dissection

Purpose: Stent-graft repair of acute aortic dissection has only recently begun, and the true efficacy and safety of this technique have not yet been clarified. In this report, we describe a significant, previously unreported complication following stent-graft repair of acute aortic dissection. Materials and Methods: Fourteen patients with acute aortic dissection underwent stent-graft repair. All of the entry tears were located in the descending thoracic aorta. Five patients had type A aortic dissection, and nine patients had type B aortic dissection. The entry tears were closed with stent-grafts, which were fabricated from expanded polytetrafluoroethylene and Z-stents. Results: Stent-graft placement was successfully performed without any complications in all patients. Entry closure was achieved in 13 (93%) of 14 patients. The mean follow-up period was 18 months (range, 9 days to 36 months). During this period, four patients had saccular aneurysms in the proximal descending thoracic aorta. A saccular aneurysm was noted during a mean follow-up period of 63 days (range, 38-99 days). Two of these patients were treated with stent-grafts. Conventional surgical repair is planned in one patient. The other patient is being treated with conservative management. Conclusions: Stent-graft repair is a technically feasible and effective method for the treatment of acute aortic dissection in selected patients. However, careful follow-up is mandatory to check for the development of saccular aneurysms. (J Vasc Surg 2001;34:513-8.)

Stent-graft entry closure and balloon fenestration for a case of aortic dissection accompanied by organ malperfusion

J Thorac Cardiovasc Surg 2001;121:1216-8

Acute aortic dissection with critical stenoses of the true lumen treated by transluminal stent-graft placement and findings one year after treatment

Clinical summary. A 54-year-old woman with a sudden onset of back pain was admitted to a satellite hospital of Mie University. Contrast-enhanced computed tomography (CT) revealed a DeBakey type IIIb, Stanford type B acute aortic dissection. The patient was treated medically. Nineteen days after admission, she had acute renal failure (blood urea nitrogen, 54 mg/dL; creatinine, 3.8 mg/dL) and left leg ischemia. CT disclosed severe stenosis of the true lumen at the level of the left renal artery. She was referred to Mie University Hospital for evaluation and treatment of acute aortic dissection. Her left femoral pulse was not palpable. The patient immediately underwent digital subtraction angiography (DSA), which showed that the intimal tear was located in the midportion of the descending thoracic aorta and that stenoses of the true lumen were located at the level of the diaphragm and distal to the level of the left renal artery. The left external iliac artery also had a critical stenosis. The true lumen of the right iliac artery was completely obliterated. However, the right leg was perfused by blood flow through the false lumen (Fig 1, A). Emergency transluminal stent-graft placement was subsequently performed. The stent graft was constructed of a selfexpanding, Gianturco stainless steel Z stent (Cook Critical Care, Inc, Bloomington, Ind) covered with a balloon-expandStanford type B acute aortic dissection is mainly treated medically. However, emergency surgery for type B dissection with rupture, impending rupture, end-organ ischemia, or some combination thereof is mandatory. Surgical outcomes are poor for patients with an acute type B aortic dissection with endorgan ischemia. Recently, transluminal stent-graft placement became an alternative for the treatment of aortic dissection.1,2 However, transluminal stent-graft placement for stenosis of the true lumen is not common, and the fate of a narrowed true lumen is not clear after stent-graft treatment. We report the case of a patient with acute type B aortic dissection with critical stenoses of the true lumen treated by transluminal stentgraft placement. We also discuss the effects on a narrowed true lumen 1 year after the treatment. ACUTE AORTIC DISSECTION WITH CRITICAL STENOSES OF THE TRUE LUMEN TREATED BY TRANSLUMINAL STENT-GRAFT PLACEMENT AND FINDINGS ONE YEAR AFTER TREATMENT

A Case of Acute Aortic Dissection with Dynamic ST Changes in Electrocardiogram

Acute aortic dissection is the most common catastrophic illness of the aorta. Left untreated, about 75% of patients with dissections involving the ascending aorta die within 2 weeks of an acute episode, but survival may be significantly improved by the timely institution of diagnostic modalities and appropriate medical and surgical therapy. But, approximately 10-20% of patients with acute aortic dissection present with a clinical picture of acute myocardial infarction. This sometimes can not only delay the diagnosis and adequate treatment of acute aortic dissection but also inappropriately treat with thrombolytic agents and anticoagulants which result in rapid deterioration of clinical condition of patient. We report a case of acute aortic dissection with dynamic ST changes in electrocardiogram which resulted in delay of accurate diagnosis and adequate treatment of acute aortic dissection. (Korean Circulation J 2001;31(2):251-255)

Organ malperfusion in acute aortic dissection.

Organ malperfusion in aortic dissection can precipitate a serious condition. The strategy of treatment for it has been controversial. We have focused on the strategy and outcome of acute aortic dissection with organ malperfusion. Between January 1995 and December 1998, 134 acute aortic dissection patients were admitted. There were 73 males (65.4 +/- 8.0 years old) and 61 females (66.7 +/- 7.4 years old). There were 83 patients of Stanford type A, and 51 patients of type B. Of them, 24 patients (17.9%) were complicated by organ malperfusion. The brain was affected in 4, the heart in 5, the spinal cord in 2, the liver in 1, the intestine in 1, the kidney in 4, and the lower extremities in 10 patients. Our management strategy for a patient with malperfusion in acute aortic dissection was that the antecedent operation was initially mandatory, and central grafting was secondarily considered. Refusal of operation or lethal conditions excluded 8 of the 24 patients from operation. An antecedent operation was mandatory in eight of the remaining 16 patients. The overall mortality was 33.3% (8/24 patients), and operative mortality was 31.3% (5/16 patients) in the patients with malperfusion. The overall mortality was 11.8% (13/110 patients), and the operative mortality was 11.1% (9/81 patients) in the patients without malperfusion. Organ malperfusion is a major component in the management and treatment of acute aortic dissection. Only an appropriate strategy and therapy could result in a satisfactory outcome.

Application of AdvaSeal for acute aortic dissection: experimental study

Background. In the surgical treatment of acute aortic dissection, intractable hemorrhage often occurs. We performed an animal study to test the hypothesis that a new sealant, AdvaSeal (Ethicon Inc, Johnson & Johnson Medical KK, Somerville, NJ), can close the false channel of aortic dissection. Methods. Acute descending aortic dissection was created surgically in 12 mongrel dogs. In 7 of these (treated group), AdvaSeal was applied to the false cavity for reinforcing and fusing the dissected layers and also to the suture line. The other 5 dogs (control) were left untreated. Specimens were harvested 2 weeks after surgery. Results. The sealant could be used in wet conditions. In the treated group, hemostasis was easily achieved during surgery. All false cavities were perfectly thrombosed, causing no deleterious effects related to the sealant. In the control group, all false lumina remained patent. Conclusions. The advantage of AdvaSeal was its effectiveness on wet tissue and its adhesiveness, allowing good hemostasis and closure of the false lumen. The sealant can be an easy and efficacious sealant in treatment for acute aortic dissection.

Stent for Acute Aortic Dissection

Intravascular stent placement is emerging as a less invasive treatment of acute aortic dissection originating in the descending thoracic aorta.

Treatment of Acute Aortic Dissection Complicated by Atherosclerotic Aortic Aneurysm

This study was designed to clarify the clinical characteristics and optimal management of patients who have acute aortic dissections accompanied by atherosclerotic (true) aortic aneurysm. Between January 1992 and August 1996, a total of 132 patients (Stanford type A/B = 72/60) had surgical repair or medical treatment of acute aortic dissection at our institution. Seventeen (type A/B: 5/12) of them had concurrent or previously repaired true thoracic or abdominal aortic aneurysms. There were 14 men and three women patients, ranging in age from 58 to 79 years with a mean of 70 years. Five patients developed type A dissections that affected preexisting true aneurysms located on the aortic arch (n=four) and infrarenal aorta (n=one). They all underwent emergency operations: four patients had total arch repair with resection of aortic arch aneurysms resulting in one death due to myocardial infarction, and the remaining one patient had a hemiarch repair that was followed by resection of an enlarged abdominal aortic aneurysm (AAA) 2 years later. Twelve patients developed type B dissections. Five of them had preexisting true aneurysms affected by dissection: there were three descending thoracic aortic aneurysms (DTAA) and two AAAs; rupture occurred in three patients (DTAA/AAA=one/two) while awaiting surgery. The other two patients successfully underwent emergency graft replacements of the descending thoracic aorta containing true aneurysm and dissection. No patient among the remaining seven with type B dissections, who had AAAs not affected by dissection, had an unfavorable outcome because of the presence of concurrent dissection and true aneurysm. The risk of rupture appears to be high in patients with an aortic segment where true aneurysm is affected by acute dissection. Hence, surgical repairs should be done on an emergency basis in those patients irrespective of the type of dissection.

Influence of aortic dissection on the clotting-fibrinolysis system and platelet function

Coagulopathy is still a frequent complication in the surgical treatment of acute aortic dissection. This study was designed to clarify the influence of acute aortic dissection on the clotting-fibrinolysis system and platelet function. From January 1993 to December 1994 21 patients with proven Stanford type B aortic dissection underwent a series of tests and procedures at our institution. There were 6 women and 15 men, aged 37–74 years (mean 62 years). All patients were admitted within 14 days of onset of dissection. No patient had complications requiring surgery and none died during the observation period. We observed a severe inflammatory reaction with activation of the clotting-fibrinolysis system immediately after onset of dissection. The platelet maximum aggregation rates were also decreased transiently after onset of the dissection. D-dimer values remained elevated throughout, the observation period. A rational approach to the surgical treatment of acute aortic dissection should involve coping with its activated clotting-fibrinolysis system and platelet dysfunction in addition to tissue friability.

Ultrafast computed tomography for minimally invasive coronary artery bypass grafting

J Thorac Cardiovasc Surg 1998;116:173-4

Effects of endoluminal stent-grafts on acute aortic dissection in dogs.

Acute aortic dissection is a life-threatening condition, and may be treated with aggressive hypotensive drug therapy, but emergency surgery is often necessary. We evaluated the effectiveness of stent-grafts for the treatment of acute aortic dissection. Aortic dissection was surgically created in the descending thoracic aorta in 20 adult mongrel dogs. A stent-graft was inserted in the entry position. The tested animals were divided into 4 groups based on re-entry type and blood pressure alteration rate (AR) after acute aortic dissection. After insertion of the stent, the following results were observed: a) AR improved; b) proximal descending aorta and superior mesenteric arterial flows increased; c) cardiac function improved; and d) the dissecting aortic diameter decreased in the presence of pressure gradient group. From these results, insertion of a stent-graft to treat acute aortic dissection was judged to be effective.

The surgical treatment for acute aortic dissection--a retrospective study from the statistics of affiliated hospitals of a medical school

A retrospective study was conducted for the surgical treatment on acute aortic dissection among the cardiovascular services of 5 affiliated hospital of medical school. The total of 74 cases were operated for the last 5 years period from Jan., 1991 to Dec., 1995, in which 64 cases were classified as Type A and 10 for Type B. The average age for Type A was 58.4 years old and 10% of patients were consisted of Marfan syndrome. The most frequent complications associated with dissection was aortic regurgitation (37.5%), followed by cardiac tamponade (23.4%). The surgeries were undertaken in less than 24 hours from the onset of symptom in 45.3% of patients. The localization of initial tear as was proved by intraoperative finding was at ascending aorta in 64.0%, whereas it was found at aortic arch in 21.8% of patients. The most frequent application of operative procedure was simultaneous graft replacement of ascending aorta and aortic arch (68.7%) with the use of profound hypothermia and antegrade selective cerebral perfusion (85.4%). The overall mortality rate was 25.0%, however when compared as ascending only vs ascending + arch replacement, the later group demonstrated higher mortality rate (16.6% vs 28.9%). The majority of surgical indication for Type B was hemorrhage from the dissection and 20.0% of mortality was recorded in this group of patients.

Influence of Aortic Dissection on the Clotting-Fibrinolysis System and Platelet Function

Coagulopathy is still a frequent complication in the surgical treatment of acute aortic dissection. This study was designed to clarify the influence of acute aortic dissection on the clotting-fibrinolysis system and platelet function. From January 1993 to December 1994 21 patients with proven Stanford type B aortic dissection underwent a series of tests and procedures at our institution. There were 6 women and 15 men, aged 37–74 years (mean 62 years). All patients were admitted within 14 days of onset of dissection. No patient had complications requiring surgery and none died during the observation period. We observed a severe inflammatory reaction with activation of the clotting-fibrinolysis system immediately after onset of dissection. The platelet maximum aggregation rates were also decreased transiently after onset of the dissection. D-dimer values remained elevated throughout, the observation period. A rational approach to the surgical treatment of acute aortic dissection should involve coping with its activated clotting-fibrinolysis system and platelet dysfunction in addition to tissue friability.

Surgical Clip for Compression of the Aortic Wall During Gluing

An acrylic clip was developed to compress the dissected aortic wall during gluing. These small instruments have a concave-convex contact face adjusted to the most common graft size. There are several advantages to this method of treatment of acute aortic dissection.

Successful Detection of Cerebral Hypoperfusion by near Infrared Spectroscopy in Two Patients with Dissecting Aortic Aneurysm

Near infrared spectroscopy is being used to monitor mixed cerebral oxygen saturation intraoperatively. In 2 patients receiving surgical treatment for acute aortic dissection, cerebral hypoperfusion was detected by near infrared spectroscopy (INVOS3100, Somanetics Corporation, Troy, MI, USA) and corrected accordingly. Near infrared spectroscopy may help to prevent serious neuropsychiatric complications in surgery for aortic arch dissection.

Treatment of Aortic Dissections with a Percutaneous Intravascular Endoprosthesis: Comparison of Covered and Bare Stents

The authors developed a percutaneous endoprosthesis for treatment of aortic dissections. The device is a Gianturco stent wrapped with Dacron or nylon mesh. Effectiveness of the covered stent versus a bare stent was compared in the treatment of acute aortic dissection. Experimental aortic dissections were created in 10 mongrel dogs. Occlusion of intimal tears was attempted with covered stents in five dogs (group 1) and with bare stents in the remaining five dogs (group 2). In group 1, entry tears were obliterated within 1 day (n = 3) or 1 week (n = 2) after stent placement and false lumina were thrombosed within 1 week (n = 3) or 1 month (n = 2). In group 2, entry tears and false lumina remained patent. Histologic specimens showed that the covered stents were entirely covered with smooth neointima. This endoprosthesis offers an alternative to surgical treatment for dissections of the descending aorta.