Coronary malperfusion due to type A aortic dissection: mechanism and surgical management

BACKGROUND: Coronary malperfusion associated with aortic dissection is relatively rare, but when it occurs, it is fatal to the patient. To salvage such moribund patients, aggressive coronary revascularization concomitant with aortic repair is essential. We review the surgical results and mechanism of malperfusion in a group of 12 patients with coronary malperfusion caused by type A aortic dissection, and we discuss our surgical approach. METHODS: Between March 1990 and March 2003, 12 patients (6.1%) from a total of 196 consecutive patients with acute type A aortic dissection undergoing surgery suffered coronary malperfusion associated with the dissection. There were 4 men and 8 women (mean age, 60.8 +/- 8.3 years). Nine patients had acute myocardial infarction due to dissection before surgery, and 3 patients suffered coronary malperfusion after aortic declamping. RESULTS: Hospital mortality rate was 33.3% (4 patients). The mortality rate was higher than that in patients without coronary malperfusion (33.3% vs. 8.2%, p = 0.019). Three patients could not be weaned from cardiopulmonary bypass, and 1 patient died of heart failure in the intensive care unit. Involved coronary arteries included the right coronary artery (8 patients), left coronary (2 patients), and both (2 patients). Mechanisms of coronary obstruction were compression (2 patients), coronary dissection (7 patients), and coronary disruption (3 patients). Coronary artery bypass grafting was performed concomitant with aortic repair. CONCLUSIONS: Acute type A aortic dissection with coronary involvement is associated with high mortality rate, aggressive coronary revascularization and early aortic repair with simple techniques are necessary to salvage these critically ill patients.     

Impact of organ malperfusion on mortality and morbidity in acute type A aortic dissections

BACKGROUND: Organ malperfusion is a serious complication of acute type A aortic dissection. Management and outcome of malperfusion has been discussed in this study. METHODS: Between November 1994 and May 2003, 118 patients with acute type A aortic dissections were operated. Fifty-seven patients (48.3%) were complicated with organ malperfusion, which is considered as group I. Seventy-three ischemic events were seen in 57 patients with organ malperfusion. Patients in group I were divided into four subgroups according to affected organ system including limb (38 events), coronary (9 events), renal (2 events), visceral (9 events), and cerebral (15 events) ischemia. Sixty-one patients without organ malperfusion constitute group II. RESULTS: The hospital mortality rate was 42.1% (24 of 57) in patients with malperfusion, 14.75% (9 of 61) in group II (p = 0.001), and 27.9% (33 of 118) in all patients. Postoperative complications such as mediastinal hemorrhage, low cardiac output, gastrointestinal system complications, acute renal failure, and multiple organ failure were higher in group I. Mesenteric and limb ischemia associated with high mortality. Multivariate analysis reveals that visceral malperfusion is the strongest predictor of postoperative mortality (odds ratio: 25.09, p = 0.000). Isolated coronary malperfusion had the lowest mortality (one patient, 16.6%) among the patients with organ malperfusion. CONCLUSIONS: Acute type A aortic dissections with organ malperfusion has higher postoperative mortality and morbidity. Immediate aortic repair is our management strategy in patients with limb, coronary, and neurological malperfusion. To reduce the extremely high mortality with mesenteric malperfusion, new strategies should be investigated such as surgical delay with interventional procedures.     

A single-center experience treating renal malperfusion after aortic dissection with central aortic fenestration and renal artery stenting

OBJECTIVE: Patients with aortic dissection were studied to define (1) anatomic and physiologic derangements in renal artery blood flow, (2) differences in clinically suspected renal malperfusion and true functional malperfusion, and (3) variations in endovascular interventions for the treatment of renal malperfusion. METHODS: The cohort comprised 165 patients (mean age, 58 years) with dissections who were thought to have malperfusion sufficient to require arteriography. They were treated from 1996 to 2004 for acute (n = 115) or chronic (n = 50) aortic dissections (75 had type A, 90 had type B lesions). All patients had suspected peripheral vascular malperfusion (ie, cerebral, spinal, mesenteric, renal, or lower extremity vascular beds). Renal malperfusion was suspected in 88 patients secondary to worsening hypertension (n = 34), evolving renal insufficiency (n = 37), computed tomography evidence of impaired renal blood flow (n = 13), or a combination of factors (n = 4). Patients underwent angiographic and intravascular ultrasound studies. Renal malperfusion was confirmed with a systolic gradient between the aortic root and renal hilum (average, 44 mm Hg). RESULTS: Right renal arteries arose exclusively from the true lumen in 115 patients (70%), the false lumen in 11 (7%), and both lumens in 37 (23%). Left renal arteries arose exclusively from the true lumen in 69 patients (42%), the false lumen in 32 (20%), and both lumens in 62 (38%). Angiographic confirmation of malperfusion existed in 59 patients (67%) of the 88 suspected of such, and in 31 patients (39%) of the 79 with suspected malperfusion of nonrenal tissues. Of the 90 patients with confirmed renal malperfusion, 71 underwent endovascular therapy, including isolated renal artery stenting (n = 31), as well as proximal aortic fenestration with or without aortic stenting (n = 24), or both renal and aortic intervention (n = 16). Residual pressure gradients averaged 8.1 mm Hg after these interventions. Five procedure-related complications (7%) occurred. The periprocedural postintervention mortality rate was 21% (n = 15), including multisystem organ failure (n = 7), false lumen rupture (n = 3), reperfusion injury (n = 2), cerebral ischemia (n = 1), cardiac arrest (n = 1), and unknown (n = 1). CONCLUSIONS: Percutaneous aortic fenestration and renal artery stenting are both technically feasible and associated with an acceptable complication rate. Most patients respond well symptomatically, obviating the need for immediate surgical relief of renal artery obstruction and allowing for renal malperfusion recovery.     

A multi-centre additive and logistic risk model for in-hospital mortality following aortic valve replacement.

OBJECTIVE: To develop a multivariate prediction model for in-hospital mortality following aortic valve replacement. METHODS: Retrospective analysis of prospectively collected data on 4550 consecutive patients undergoing aortic valve replacement between 1 April 1997 and 31 March 2004 at four hospitals. A multivariate logistic regression analysis was undertaken, using the forward stepwise technique, to identify independent risk factors for in-hospital mortality. The area under the receiver operating characteristic (ROC) curve was calculated to assess the performance of the model. The statistical model was internally validated using the technique of bootstrap resampling, which involved creating 100 random samples, with replacement, of 70% of the entire dataset. The model was also validated on 816 consecutive patients undergoing aortic valve replacement between 1 April 2004 and 31 March 2005 from the same four hospitals. RESULTS: Two hundred and seven (4.6%) in-hospital deaths occurred. Independent variables identified with in-hospital mortality are shown with relevant co-efficient values and p-values as follows: (1) age 70-75 years: 0.7046, p<0.001; (2) age 75-85 years: 1.1714, p<0.001; (3) age>85 years: 2.0339, p<0.001; (4) renal dysfunction: 1.2307, p<0.001; (5) New York Heart Association class IV: 0.5782, p=0.003; (6) hypertension: 0.4203, p=0.006; (7) atrial fibrillation: 0.604, p=0.002; (8) ejection fraction<30%: 0.571, p=0.012; (9) previous cardiac surgery: 0.9193, p<0.001; (10) non-elective surgery: 0.5735, p<0.001; (11) cardiogenic shock: 1.1291, p=0.009; (12) concomitant CABG: 0.6436, p<0.001. Intercept: -4.8092. A simplified additive scoring system was also developed. The ROC curve was 0.78, indicating a good discrimination power. Bootstrapping demonstrated that estimates were stable with an average ROC curve of 0.76, with a standard deviation of 0.025. Validation on 2004-2005 data revealed a ROC curve of 0.78 and an expected mortality of 4.7% compared to the observed rate of 4.1%. CONCLUSIONS: We developed a contemporaneous multivariate prediction model for in-hospital mortality following aortic valve replacement. This tool can be used in day-to-day practice to calculate patient-specific risk by the logistic equation or a simple scoring system with an equivalent predicted risk.     

Rapid and safe establishment of cardiopulmonary bypass in repair of acute aortic dissection: improved results with double cannulation

There is no agreement at present as to which is the optimal site for artery cannulation for cardiopulmonary bypass in repair of acute aortic dissection (AAD). We have employed right axillary artery cannulation (RAAC) in combination with femoral artery cannulation to overcome the drawbacks of single cannulation. From January 2000 to August 2006, 88 patients underwent emergency surgical repair of the aortic arch (mean age 65+/-13 years, 37 men) for AAD. All operations were performed under hypothermic circulatory arrest with antegrade selective cerebral perfusion. Preoperatively, nine patients were in shock and 18 patients showed malperfusion. The average duration of circulatory arrest was 52+/-17 min and that of myocardial ischemia was 135+/-53 min. Total aortic arch replacement was done in 47 patients and hemiarch aortic replacement in 41. The hospital mortality rate was 2.3% (2 of 88); the fatal cases were among those who were in shock preoperatively. The perioperative stroke rate was 5.7% (5 of 88). The hospital mortality rate of the 25 patients with preoperative malperfusion was 4.0% (1 of 25); the fatal case had coronary malperfusion. Our approach for AAD was associated with a low mortality even in patients with malperfusion.     

Risk factors for secondary dilatation of the aorta after acute type A aortic dissection.

OBJECTIVES: Prompt diagnosis of subsequent dilatation of the dissected aorta is crucial to reduce late mortality in these patients. This study focuses on risk factors for dilatation of the aorta after type A aortic dissection (AADA) affecting a normal-sized or slightly dilated aorta. METHODS: Overall 531 CT scans were analysed. Patients were included in the study if at least 3 CT scans were available after operative repair. 64 patients (59.8%) out of 107 patients full-field the inclusion criteria. Volumetric analyses of the aorta were performed. Patients were divided in 3 groups: group A included 26 patients (40.6%) without progression of the aortic diameter, group 2, 27 patients (42.2%) with slight progression and group 3, 11 patients (17.2%) with important progression, requiring surgery in 9 patients (81.8%). Risk-factors for progression of the aortic size were analysed and compared between the groups. RESULTS: Patients from group 3 were younger 57.7+/-13.4 vs. 61.9+/-11.6 in group 1 (P<0.05) and were more frequent female (45.4 vs. 23.1%; P<0.05). Dissection of the supraaortic branches (100 vs. 80.8%; P<0.05), the presence of preoperative cerebral, visceral or peripheral malperfusion (54.6 vs. 26.9%; P<0.05) and contrast enhancement in the false lumen during the follow-up (72.7 vs. 57.7%; P=0.07) were additional risk factors for late aortic dilatation in these patients. CONCLUSIONS: Acute type A aortic dissection in younger patients, involving the supraaortic branches and/or combined with malperfusion syndrome favour secondary dilatation. A close follow-up is mandatory to prevent acute complications of the diseased downstream aorta following repair of a AADA.     

Mid-term outcome with surgery for type B aortic dissections: a single center experience

BACKGROUND: The approach to acute and chronic type B aortic dissection has changed significantly over the past years. In this aspect, we have reviewed our single-center experience in surgery for type B dissections and compared the current data presented by other centers. METHODS: Twenty-nine patients operated at our center for type B aortic dissection (14 acute, 15 chronic) were reviewed over the years between 1996 and 2004. All patient data in addition to immediate and late outcome following surgery were noted. RESULTS: The mean age in acute and chronic groups was 53 +/- 16 versus 62 +/- 12 years, respectively (p = 0.1). Hospital mortality was 4 patients. The mean period in the intensive care unit was 4.2 +/- 3.1 days. Follow-up time was 36 +/- 11 months. Median interval between the initial symptoms and surgery was 3.8 days for acute cases. No patients underwent reoperation in acute patients; whereas 3 underwent reoperation in the chronic group. False lumen patency rates in acute and chronic dissections were 16.7% versus 46% after 24 months (p< 0.05). Distal anastomoses included both true and false lumens in 83% of the chronic cases with false lumen patency. The mean reoperation-free survival was 79.35 months with standard error of 5.57 months (95% CI, 68.42 to 90.27) in all patients. CONCLUSIONS: Open surgery in acute type B dissections yielded excellent immediate and long-term durability in our series with no false lumen patency or aortic expansion. However, incorporation of both false and true lumina into distal anastomosis in patients with chronic dissection resulted in false lumen patency with aortic expansion.     

Separate grafts or en bloc anastomosis for arch vessels reimplantation to the aortic arch

BACKGROUND: This study compares the results of the separated graft technique and the en bloc technique as a method of arch vessels reimplantation during surgery of the aortic arch and determines the predictive risk factors associated with hospital mortality and adverse neurologic outcome during aortic arch repair. METHODS: Between October 1995 and March 2002, 352 patients (mean age 64.9 +/- 11.3 years; urgent status: 49/352 [13.9%]) underwent surgery of the aortic arch using the separated graft technique (group A: n = 230 [65.3%]) and the en bloc technique (group B: n = 122 [34.7%]) to reimplant the arch vessels. An aortic arch replacement was performed in 32 patients (9.1%), an ascending aorta and arch replacement in 222 patients (53.1%), an aortic arch and descending aorta replacement in 16 patients (4.5%), and a complete replacement of the thoracic aorta in 82 patients (23.3%). Brain protection was achieved by means of antegrade selective cerebral perfusion in all patients. The mean cardiopulmonary bypass time was 204.8 +/- 61.9 minutes (group A: 199.7 +/- 57.0 minutes; group B: 214.5 +/- 69.4 minutes; p = 0.033), the mean myocardial ischemic time was 121.5 +/- 43.2 minutes (group A: 116.7 +/- 38.9 minutes; group B: 130.80 +/- 49.4 minutes; p = 0.003), and the mean antegrade selective cerebral perfusion time was 84.5 +/- 36.4 (group A: separated graft technique 91.3 +/- 36.3 minutes; group B: 70.6 +/- 32.7 minutes; p = 0.000). RESULTS: Overall hospital mortality was 6.8% (group A: 6.5%; group B: 7.4%; p = not significant [NS]). The permanent neurologic dysfunction rate was 3.5% (group A: 4.0%; group B: 2.5%; p = NS). The transient neurologic dysfunction rate was 5.4% (group A: 5.5%; group B: 5.2%, p = NS). Postoperative systemic morbidity was similar in the two groups. A logistic regression analysis revealed preoperative cardiac tamponade (p = 0.011; odds ratio [OR] = 5.9) and cardiopulmonary bypass time (p = 0.010; OR = 1.01/min) to be independent predictors of hospital mortality. None of the analyzed preoperative variables were associated with an increased risk of permanent neurologic dysfunction. Age more than 70 years old (p = 0.029, OR = 5.7), myocardial revascularization (p = 0.001, OR = 2.9), and pump time (p = 0.013, OR = 1.01/min) were indicated as independent predictors of transient neurologic dysfunction by logistic regression. CONCLUSIONS: Antegrade selective cerebral perfusion was confirmed to be a safe method of cerebral protection allowing complex aortic arch operations to be performed with acceptable results in terms of hospital mortality and neurologic outcome. The separated graft technique had no adverse impact on hospital mortality and morbidity.     

Does malperfusion syndrome affect early and mid-term outcome in patients suffering from acute type A aortic dissection?

It is well known that malperfusion syndrome (MPS) increases early mortality of patients suffering from acute type A aortic dissection (AADA). The aim of the present study was to analyze the outcome of patients who survived after surgical treatment of AADA with or without MPS. Data of 227 consecutive patients, who underwent surgery for AADA, were analyzed. The impact of MPS on in-hospital data and outcome was analyzed. Quality of life (QoL), using the short form 36 health survey questionnaire (SF-36), and late mortality were analyzed. Seventy-five patients (33%) with AADA had preoperative MPS. In 31 patients (41.3%), central nervous system (CNS) was involved and in 33 patients (44%) MPS of the extremities was present. Coronary malperfusion was found in 9 patients, renal in 8 patients and visceral malperfusion in 5 patients. Mean age in the group with MPS was 61.9+/-9.1 compared to 61.6+/-12.7 years without MPS (P=ns). In-hospital mortality was 18.7% in patients with MPS, compared to 9.9% without MPS (P<0.05). Follow-up revealed a significant poorer outcome in patients with MPS, with a 3-year-survival of 73.3% in patients with MPS and 86.2% without MPS (P<0.05). Average SF-36 values were lower in patients with MPS (78.3+/-12.8 vs. 87.8+/-11.9; P=ns), which is mainly due to patients with CNS-MPS, who showed an average SF-36 of 65.8+/-17.9 (P<0.05). AADA associated to MPS carries a higher early- and mid-term mortality. Postoperative mid-term QoL, however, except in patients with CNS-MPS and persistent neurological deficits, is fairly good and similar to patients who underwent successful surgery for AADA without MPS.     

A preoperative index of mortality for patients undergoing surgery of type A aortic dissection.

BACKGROUND: The aim of this study was to identify and stratify the most important preoperative factors for in-hospital death after surgery for type A aortic dissection. METHODS: From January 1985 to June 1998, 108 patients underwent surgery for type A aortic dissection. 89.9% of the patients had an acute type A dissection (AD), whereas 11.1% had a chronic dissection (CD). Cardiac tamponade and shock occurred in 22% and 14.8% of the patients, respectively. The location of the primary intimal tear was in the ascending aorta in 71.2% of the cases, in the arch in 16.6% and in the descending aorta in 7.4%. Univariate and multivariate analyses were conducted to identify non-embolic variables independently correlated to in-hospital death. A predictive model of in-hospital mortality was then constructed by means of a mathematical method with the variables selected from logistic regression analysis. RESULTS: The overall in-hospital mortality rate was 20.3% (22/108 patients), being 9% for CD and 21.6% for AD. Emergent procedures had an in-hospital mortality rate of 47.6%, whereas non-emergent operations had an in-hospital mortality rate of 13.7% (p<0.01). Univariate analysis revealed among 39 preoperative and operative variables, age (years), age >70 years, remote myocardial infarction, cerebrovascular dysfunction, diabetes, preoperative renal failure, shock, cardiopulmonary bypass time (minutes), emergency operation as factors associated to in-hospital death (p<0.05). Stepwise logistic regression analysis selected as independent predicting variables (p<0.05), remote myocardial infarction (p=0.006), preoperative renal failure (p=0.032), shock (p=0.001), age >70 years (p=0.007). Finally, a probability table of death risk was obtained with the logistic regression coefficients. The lower death probability (10.6%) was calculated in absence of risk variables; the higher one in presence of all of them (79.7%). Between these extremes, a total of 64 combinations of death risk were obtained. CONCLUSIONS: Increasing age, shock, coronary artery disease and renal failure are variously associated to a high risk of in-hospital death after surgical correction of type A aortic dissection. This predictive model of death probability allows to collocate preoperatively patients with type A aortic dissection at different levels of risk for in-hospital death.     

Organ malperfusion in acute aortic dissection.

OBJECTIVE: 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. SUBJECTS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.     

Surgical results in acute type A aortic dissection.

Currently international registry data present the patient mortality with acute type A aortic dissection managed non-surgically to be 58%, and managed surgically to be 26%. Many articles consistently report the hospital mortality exceeding 20% in western countries. Many factors, such as cardiac tamponade and dissection-related organ malperfusion, contribute to hospital mortality and morbidity. In Japan, the number of patients enrolled in the annual reports has been increasing and the surgical results have been improving year by year. In-hospital mortality has decreased to less than 20% since 1999. Since the beginning of our aortic program, a total of 98 patients underwent emergency operations, and the operative mortality and in-hospital mortality were 5.1% and 6.1%, respectively. In a recent series since 2001, the operative and in-hospital mortalities were remarkably low; 2.8% and 3.2% respectively. We were able to benefit greatly by various innovative technologies which include open distal anastomosis using hypothermic circulatory arrest with antegrade cerebral perfusion, gelatin-resorcin-formaldehyde (GRF) glue, branched presealed Dacron graft, and antegrade arterial perfusion. Our tear-oriented surgery could be justified in many patients in order to improve the surgical results. In patients with preoperative organ malperfusion, it is still challenging to improve the mortality and morbidity.     

Infradiaphragmatic malperfusion of acute aortic dissection associated with previous abdominal aortic aneurysm repair

Purpose

To evaluate the association of previous abdominal aortic aneurysm (AAA) graft replacement with infradiaphragmatic malperfusion in patients with acute aortic dissection.

Methods

Between November 2006 and June 2011, 133 patients were referred to our hospital for management of acute aortic dissection. Eight (6.0 %) of these patients had undergone AAA graft replacement prior to the acute aortic dissection. We compared the computed tomography (CT) images of these 8 patients with those of the remaining 125 patients without previous AAA graft replacement, in terms of organ ischemia as a complication induced by acute aortic dissection.

Results

Infradiaphragmatic malperfusion from acute aortic dissection was confirmed in four of the eight patients who had undergone AAA graft replacement. Contrasted CT scan images indicated that the main cause of infradiaphragmatic malperfusion was collapse of the true lumen from compression by the false lumen into the suprarenal aorta. Although there was no significant difference between the groups in terms of cerebral ischemia and myocardial ischemia, bilateral leg ischemia and visceral ischemia occurred more frequently in the patients who had undergone AAA graft replacement.

Conclusion

Previous AAA graft replacement is a risk factor for infradiaphragmatic malperfusion in patients with acute aortic dissection.     

Infective endocarditis in maintenance hemodialysis patients: fifteen years' experience in one medical center

BACKGROUND: Infective endocarditis (IE) is a serious infectious condition, with high morbidity and mortality in hemodialysis (HD) patients. This study was undertaken to determine the IE risk factors in maintenance HD patients, and the mortality risk factors. METHODS: We retrospectively reviewed all IE cases of maintenance HD patients at our center over the past 15 yrs (the study group). Regular HD patients without IE in the same period were used as the control group. The basic data of the two groups were analyzed to determine IE risk factors in HD patients. The in-hospital parameters of survival and mortality in the study group patients were used for mortality risk factors analysis. RESULTS: There were 18 definite, and two possible, IE diagnoses in the study group and no cases in the 268 controls. There was no significant difference in age, sex, diabetes, hypertension, underlying malignancy, previous cerebral vascular accident (CVA) history, and calcium multiplied by phosphate product. There was a significant difference between the two groups (study group vs. controls) in pacemaker implant history (15 vs. 1.1%, p<0.01), previous heart surgery history (15 vs. 0.4%, p<0.01), congestive heart failure (CHF) (50 vs. 10.4%, p<0.05), duration on maintenance HD (12.9+/-19.1 vs. 57.9+/-42.3 months, p<0.001), serum albumin at the time of admission (2.91+/-0.40 vs. 3.96+/-0.52 g/dL, p<0.001). There were more patients dialyzed via non-cuffed dual-lumen catheters in the study group (55 vs. 0%, p<0.001), and fewer patients dialyzed via arteriovenous fistula (AVF) (25 vs. 87.7%, p<0.001). The mortality in HD patients with IE was high (60%), especially in patients with methicillin-resistant Staphylococcus aureus (MRSA) endocarditis (100%). The most common pathogen was S. aureus (n=12). MRSA was more common than methicillin-susceptible S. aureus (MSSA) (67 vs. 33%). Univariant analysis of in-hospital clinical parameters for mortality revealed no significant difference in age, diabetes, dual-lumen catheter implantation, serum albumin, time to diagnosis, and time to antibiotic use. Borderline statistical significance was noted in serum C-reactive protein (CRP) (p=0.051), and blood glucose level (p=0.056). There were more IE cases due to MRSA in the mortality group than in the survival group (8 vs. 0 cases, p=0.013), but fewer cases due to MSSA (0 vs. 4 cases, p=0.050). CONCLUSIONS: IE should be considered in HD patients with the following risk factors, which include previous heart surgery or pacemaker implantation, shorter HD duration, and especially for patients dialyzed via dual-lumen catheters. The in-hospital clinical parameters including CRP and blood sugar level can offer information concerning prognosis. Since MRSA has increased in recent years and is associated with high mortality, strategies for prevention and treatment require development.     

Acute descending aortic dissections: management of visceral, spinal cord, and extremity malperfusion

Acute descending aortic dissection is considered the most catastrophic event affecting the aorta and occurs two to three times more often than rupture of abdominal aortic aneurysms. The therapeutic aim in treating acute dissection is not only directed at the prevention of aneurysmal development and rupture but also to prevent and treat complications such as malperfusion syndrome. According to Lauterbach and coworkers patients with symptomatic malperfusion syndromes have a 51% mortality rate compared with a 29% mortality rate in patients who do not. The surgical in-hospital mortality rate in patients with mesenteric or peripheral vascular ischemic complications may be as high as 89%. Despite an improvement in diagnosing dissections and malperfusion syndromes, and despite improved operative techniques and a better understanding of the significance of perioperative care, the surgical mortality rate can be as high as 50%. Endovascular techniques are constantly evolving that provide an alternative to open procedures. The goal of this article was to review the pathogenesis of malperfusion syndromes in aortic dissection, discuss the current modalities to treat malperfusion of the spinal cord, viscera, and extremities, and examine the results of the treatments used today.     

Thoracic endovascular repair for acute complicated type B aortic dissections

Objective

This study retrospectively assessed in-hospital mortality and long-term results of emergency thoracic endovascular aortic repair (TEVAR) for patients with life-threatening acute complicated type B aortic dissection (acTBD).

Determinants of Early and Late Outcome after Surgery for Type A Aortic Dissection

The aim of this study was to identify the most important variables associated with early and late mortality in patients operated on for type A aortic dissection over a 15-year period. From January 1984 to March 1999, 110 patients underwent surgery for type A aortic dissection. The 88.1% of patients had an acute type A dissection (AD) and 11.8% had a chronic dissection (CD). Cardiac tamponade and shock occurred in 21.8% and 14.5% of the patients, respectively. The location of the primary intimal tear was in the ascending aorta in 70.9% of cases, in the arch in 17.2%, and in the descending aorta in 7.2%. Univariate and multivariate analyses were conducted to identify non-embolic variables independently correlated to in-hospital death. Kaplan-Meier and Cox regression analyses and hazard function for death risk were used to analyze factors influencing overall and surgical survival. The overall in-hospital mortality rate was 20.9% (23/110 patients), being 9% for CD and 21.6% for AD. Emergent procedures had an in-hospital mortality rate of 47.6%, whereas nonemergent operations had an in-hospital mortality rate of 13.7% (p < 0.01). Univariate analysis revealed 41 preoperative and operative variables, including age (years), age >70 years, remote myocardial infarction, cerebrovascular dysfunction, diabetes, preoperative renal failure, shock, cardiopulmonary bypass time (minutes), emergency operation, as factors associated to in-hospital death (p < 0.05). Stepwise logistic regression analysis for in-hospital death selected as independent predicting variables (p < 0.05) remote myocardial infarction [p = 0.006, odds ratio (OR) = 1.9], preoperative renal failure (p = 0.031; OR = 0.8), shock (p = 0.001; OR = 3.1), and age >70 years (p = 0.007; OR = 1.7). Follow-up ranged from 9 to 172 months (median 78 months), with Kaplan-Meier survivals for all the patients and hospital survivors of 42% and 54% at 10 years, respectively. Cox regression analysis has identified postoperative stroke [relative risk (RR) = 3.7; p = 0.012), intimal tear in the aortic arch (RR = 2.3; p = 0.036), and postoperative renal failure (RR = 4.5; p = 0.007) as independent predictors of reduced survival at follow-up. When this kind of analysis was performed on hospital survivors only, preoperative renal dysfunction (RR = 1; p = 0.013), reoperation (RR = 1.7; p = 0.004) and intimal tear in the aortic arch (RR = 1.2; p = 0.002) emerged as risk factors. The actuarial freedom from reoperation was 85.4% at 5 years. Multiple factors still influence early and late survival after surgery for type A aortic dissection. Preoperative renal impairment both affects early and late outcome. Early postoperative course affects late outcome in hospital survivors. The presence of the intimal tear in the aortic arch has a negative impact on late survival.     

Ascending aorta cannulation in acute type A aortic dissection

Objective: Antegrade perfusion for type A acute aortic dissection prevents malperfusion and retrograde cerebral embolism during cardiopulmonary bypass. Prompt establishment of antegrade perfusion via ascending aorta may improve the surgical results of type A dissections, especially in the situations of hemodynamic instability. Thus, we evaluated the efficacy of use of the dissected ascending aorta as an alternative arterial inflow. Methods: Between 2002 and 2006, 32 patients underwent prosthetic graft replacement of the ascending aorta or hemiarch for acute type A aortic dissection. The ascending aorta was routinely cannulated, in addition to the femoral artery, with a heparin-coating flexible cannula for arterial inflow, using Seldinger technique, and by epiaortic ultrasonographic guidance (n = 6). Antegrade systemic perfusion via ascending aorta was performed. Results: Ascending aorta cannulation was safely performed in all cases. There was no malperfusion or thromboembolism due to ascending aorta cannulation. Cardiopulmonary bypass was established within 30 min after skin incision. There was one in-hospital death due to duodenal bleeding (1/32 = 3.1%), two cases of cerebral infarction (2/32 = 6.3%), and one case of pulmonary embolism. Twenty-nine patients (29/32 = 90.6%) were discharged in New York Heart Association class I and have been followed up uneventfully for a mean of 17 months. Conclusions: Antegrade perfusion via the ascending aorta was successfully performed with low mortality and morbidity. With ultrasound-guided Seldinger technique, ascending aorta cannulation has a potential to be a simple and safe option that enables rapid establishment of antegrade systemic perfusion in patients with acute type A aortic dissection.     

Advantages of subclavian artery perfusion for repair of acute type A dissection.

OBJECTIVE: Arterial perfusion through the right subclavian artery is proposed to avoid intraoperative malperfusion during repair of acute type A dissection. This study evaluated the clinical and neurological outcome of patients undergoing surgery of acute aortic type A dissection following subclavian arterial cannulation compared to femoral artery approach. METHODS: From 1/97 to 1/03, 122 consecutive patients underwent surgery for acute type A aortic dissection. Subclavian cannulation was performed in 62 versus femoral cannulation in 60 patients. Clinical characteristics in both groups were similar. Mean age was 61 years (SD+/-14 years, 72% male) and mean follow-up was 3 years (+/-2 years). Patient outcome was assessed as the prevalence of clinical complications, especially neurological deficits, mortality at 30 days, perioperative morbidity and time of body temperature cooling and analyzed by nominal logistic regression analysis for odds ratio calculation. RESULTS: Arterial subclavian cannulation was successfully performed without any occurrence of malperfusion in all cases. Patients undergoing subclavian cannulation showed an odds ratio of 1.98 (95% CI 1.15-3.51; P=0.0057) for an improved neurological outcome compared to patients undergoing femoral cannulation. Re-exploration rate for postoperative bleeding was significantly reduced in the subclavian group (P<0.0001), as well as occurrence of myocardial infarction (P<0.0001) and duration for body temperature cooling (P=0.004). The 30-day mortality of patients with femoral cannulation was significantly higher compared to patients with subclavian artery cannulation (24 versus 8%; P=0.0179). CONCLUSIONS: Arterial perfusion through the right subclavian artery provides an excellent approach for repair of acute type A dissection with optimized arterial perfusion body perfusion and allows for antegrade cerebral perfusion during circulatory arrest. The technique is safe and results in a significantly improved clinical and especially neurological outcome.     

The acute mesenteric ischemia - not understood or incurable?

PURPOSE: Despite surgical research and progress, the high mortality of acute intestinal ischemia seems to be improved insignificantly over the past fifty years. In this study we analyzed the specific diagnostic and therapeutic problems of the disease in order to improve further management of acute mesenteric ischemia. Methods: From 1979 until 2000 64 patients (female 31, male 33) with a mean age of 64 (30-89) years underwent operation for primary intestinal ischemia at our institution. All medical and surgical records and imaging studies were reviewed retrospectively. Follow up consisted of clinical examination and duplex sonography. RESULTS: Only in 26 patients (41 %) a preoperative diagnostic work-up including angiography 12 and CT 14 was performed, whereas in 42 cases the intestinal ischemia was diagnosed during surgical exploration. Intestine malperfusion was caused primarily by venous thrombosis in 9 cases (14 %) and by arterial occlusive disease in 55 cases (86 %). Arterial disorders consisted of arterial thrombosis in 19 cases (30 %), arterial embolism in 18 cases (28 %), aortic or mesenteric artery dissection in 10 cases (15 %), non occlusive disease (NOD) in 5 cases (8 %), trauma 3 cases (5 %). Five different therapeutic strategies were applied: group I: Intestinal resection: 24 patients, anastomotic insufficiency 5 (39 %), mortality 11 (46 %), group II: intestinal artery revascularization: 5 patients, secondary patency rate 80 %, mortality 40 %, GROUP III: Intestinal artery revacularization and perfusion with Ringer's solution: 11 patients, mortality 8 (73 %), group IV intestinal artery revascularization and intestinal resection: 3 patients, mortality 100 %, group V intestinal artery revascularization and perfusion and intestinal resection: 3 patients, mortality 33 %. A second look operation was performed in 29 cases (40 %) and displayed malperfusion in 72 %. Only 21 of 64 patients survived the acute intestinal ischemia (in hospital mortality was 67 %). Delayed diagnostic and operation caused higher mortality (interval 10 hours: mortality 59 %, interval 37 hours mortality; 71 %, p = 0,06). Follow up after 61 (4-72) months of 21 patients (100 %) could be achieved. Ten patients (48 %) had meanwhile died, 5 patients (50) % as consequence of mesenteric ischemia, the others of unrelated reasons. Eleven patients are still alive without clinical signs of intestinal ischemia. CONCLUSIONS: Early diagnosis before hospitalisation and in-hospital (arteriography) and operation are essential to improve the outcome of patients with acute intestinal ischemia. To avoid short bowel syndrome bowel resection should be combined with mesenteric revascularization. Resection of malperfused bowel should be done cautiously and should be followed automatically by second look operations. Special expertise and good team work of visceral and vascular surgeons are required to achieve better therapeutic results.