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.

Initial management of acute type-A aortic dissection with a thrombosed false lumen: a retrospective cohort study

PURPOSE

Acute type-A aortic dissection with a clotted false lumen is often managed conservatively; however, we found that surgery has a better outcome.

METHODS

Enhanced computed tomography (CT) showed a clotted false lumen in the ascending aorta in 38 (33.3%) of 114 patients with acute type-A aortic dissection. After the exclusion of 8 patients whose condition was too critical for comparison, 13 patients who were hemodynamically stable and did not have pericardial effusion, organ ischemia, or a dilated ascending aorta greater than 50 mm in diameter, were managed conservatively (group C) and 17 were managed surgically (group S). We compared the early and late results of both groups.

RESULTS

The early mortality rates were 23.1% in group C and 0% in group S ( P = 0.037). The early deaths in group C were caused by redissection in the acute phase. The actuarial survival rates and dissection-related event-free rates 5 years after onset in groups C and S were 64.1% and 80.8% ( P = 0.131) and 46.2% and 92.9% ( P = 0.002), respectively.

CONCLUSION

The early mortality rate and dissection-related event-free rate were better after surgery than after conservative treatment. The indications for conservative management should be limited because redissection is usually fatal.

Descending Thoracic Aortic Rupture: Role of Endovascular Stent-Grafting

BACKGROUND

The mortality of patients with descending thoracic aortic rupture who are treated by conventional surgery is high. Our current strategy for the management of descending thoracic aortic rupture is to treat seriously ill patients with endovascular stent-grafting using handmade grafts, and to treat other patients with traditional open repair. The aim of this study was to assess the early results of our strategy.

METHODS

Twenty-nine consecutive patients with descending thoracic aortic rupture were referred to Sapporo Medical University Hospital from June 2001 to January 2004. Eighteen of these 29 patients were selected for endovascular stent-grafting because of polytrauma (n = 7), comorbidities (n = 6), advanced age (n = 2), past history of left thoracotomy (n = 2), and patient's preference (n = 1). The remaining 11 patients underwent traditional graft replacement of the diseased aorta. Their outcomes and follow-up data were collected and analyzed retrospectively.

RESULTS

The in-hospital mortality rate was 14% (4/29). The mortality rate for surgical patients and stent-grafting patients was 9% (1/11) and 17% (3/18), respectively. The survival rate of patients at 2 years was 63% +/- 10%. In the follow-up period, 2 of the 18 patients who underwent endovascular stent-grafting required open repair, and 1 patient underwent a redo endovascular stent-grafting procedure because of stent failure. One of these 3 patients died of an intraoperative retrograde type A aortic dissection.

CONCLUSIONS

The early results of endovascular stent-grafting for the treatment of high-risk patients with descending thoracic aortic rupture are promising. Early results of open repair can also be improved by the selection of stabilized patients. However, the requirement of reintervention indicates that detailed follow-up examinations in patients who have undergone endovascular stent-grafting with handmade stent-grafts should be performed.

Minilaparotomy Abdominal Aortic Aneurysm Repair Versus the Retroperitoneal Approach and Standard Open Surgery

PURPOSE

We evaluated the surgical results of minilaparotomy abdominal aortic aneurysm (AAA) repair in comparison with those of standard open repair and retroperitoneal approach repair.

METHODS

Between February 2000 and January 2003, 30 patients with AAA underwent minimal incision laparotomy repair (MINI) through an abdominal incision 7-12 cm long. Their clinical characteristics and in-hospital outcome were then compared with those of patients who had undergone repair of AAA by a standard open technique (OPEN) or retroperitoneal approach technique (RETRO).

RESULTS

There were significant differences between the MINI, OPEN, and RETRO groups in the time until the patient was able to resume eating (2.4 +/- 1.0 vs 4.4 +/- 2.4* vs 2.8 +/- 1.9 postoperative days [PODs], respectively; *P < 0.05), the time until ambulation outside the room (2.1 +/- 0.7 vs 3.5 +/- 1.3* vs 2.5 +/- 1.9 PODs, respectively; *P < 0.05), and the operation times (188 +/- 43* vs 256 +/- 77 vs 238 +/- 59 min, respectively; *P < 0.05).

CONCLUSION

Minilaparotomy repair is a feasible technique, which combines the benefits of a small incision with those of conventional open repair. With the exception of patients with an iliac artery aneurysm extending to the external or internal iliac artery, MINI repair should be considered for the elective treatment of patients with aortic disease.

Magnetic resonance angiographic localization of the artery of Adamkiewicz for spinal cord blood supply

BACKGROUND

The purpose of this study was to determine whether the artery of Adamkiewicz (ARM) can be detected by magnetic resonance angiography and to determine the usefulness of preoperative magnetic resonance angiography evaluation of the ARM.

METHODS

Between April 2000 and December 2003, 120 patients underwent magnetic resonance angiography for detection of the ARM. The morphology of the anterior spinal artery at the ARM junction, as revealed by magnetic resonance angiography, in 99 patients in whom ARM was preoperatively detected was classified into the following three types: noncontinuation of the anterior spinal artery above the ARM junction (type A), continuation of the anterior spinal artery above and below the ARM junction (type B), and noncontinuation of the anterior spinal artery below the ARM junction (type C).

RESULTS

The ARMs were detected in 99 (83%) of 120 patients, and from a total of 110 ARMs 105 (95%) originated from intercostal arteries branching from the left side and 94 (86%) originated between Th9 and Th11. Two ARMs were found in 11 (11%) of 99 patients in whom ARMs were detected. In 107 patients, who underwent magnetic resonance angiography to reveal the morphology of the anterior spinal artery at the ARM junction, the patterns of the anterior spinal artery were type A in 59 patients (55%), type B in 21 patients (20%), type C in 3 patients (3%) and not classified in 24 patients (22%). No spinal cord injury occurred in patients in whom the ARM had been preoperatively detected.

CONCLUSIONS

Preoperative detection of the ARM is possible by magnetic resonance angiography and is very useful for reducing the incidence of ischemic injury of the spinal cord.

Effects of ventricular unloading on apoptosis and atrophy of cardiac myocytes1

BACKGROUND

Ventricular unloading decreases cardiac ventricular mass. This loss of ventricular mass can be due to either atrophy (a reversible process) or apoptosis (an irreversible process) of the cardiac myocytes. We investigated the effect of ventricular unloading on atrophy and apoptosis of cardiac myocytes, using working and nonworking transplant heart models in rats.

MATERIALS AND METHODS

ACI rats underwent heterotopic heart transplantation with two different techniques to create working and nonworking cardiac grafts. Cardiac grafts were harvested at different time points after transplantation. TUNEL, caspase-3 assay, and electron microscopy were used to assess the degree of apoptosis while cellular atrophy was estimated by calculation of the cytoplasmic index (CI = mean sectional cytoplasmic area/nucleus).

RESULTS

Ventricular mass reduction was more pronounced in nonworking than in working hearts (P < 0.05). Apoptotic index and caspase-3 activities increased in both groups, peaking at 3 days after transplantation, but were not significantly different between the two models. The cytoplasmic index was significantly lower in nonworking than in working grafts (P < 0.05).

CONCLUSIONS

These data suggest that cellular atrophy is the primary mechanism that accounts for myocardial weight reduction following ventricular unloading. The inference is that ventricular unloading by ventricular assist devices may not cause permanent loss of cardiac myocytes, thus allowing for functional recovery.

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

BACKGROUND

In 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.

METHODS

From 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.

RESULTS

The 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).

CONCLUSIONS

The combination of the SMV/SMA ratio and lactate concentration is a useful screening method to detect mesenteric ischemia secondary to acute aortic dissection.

[Thoracoabdominal aortic aneurysm repair after detection of the Adamkiewicz artery by magnetic resonance angiography; a way to shorten operating time and improve outcome]

Surgical results were compared between 18 patients (group A) who underwent preoperative anatomic characterization of the Adamkiewicz artery by magnetic resonance angiography (MRA) and 38 patients (group B) without such imaging. In group A, intercostal or lumbar arteries related to the aneurysm were reattached to the graft only when they represented the origin of the Adamkiewicz artery. In group B, reconstruction from the Th 7 intercostal and the L2 lumbar arteries was performed whenever possible. In-hospital mortality was 16.7% in group A and 15.8% in group B. Total aortic clamp time and operating time were only 84 and 437 min in group A, compared with 134 and 589 min in group B. Three patients showed postoperative paraplegia in group B. No spinal cord injury occurred in patients whose artery had been detected preoperatively. Preoperative anatomic delineation of the Adamkiewicz artery by MRA can reduce risk of ischemic injury to the spinal cord and decrease operating time required for repair of thoracoabdominal aortic aneurysms.

Thoracoabdominal aortic aneurysm repair through redo left-sided thoracotomy

BACKGROUND

The outcome of thoracoabdominal aortic aneurysm repair through redo-left thoracotomy after operations for descending thoracic aortic aneurysms was investigated.

METHODS

Between May 1982 and March 2003, 100 patients underwent thoracoabdominal aortic aneurysm repair in elective surgery without profound hypothermic circulatory arrest. Thirty of these patients had previously undergone operations for descending thoracic aortic aneurysms. To evaluate the influence of previous descending thoracic aortic aneurysm repairs on the results of thoracoabdominal aortic aneurysm replacements, patients were divided into two groups: (1) patients who had previously undergone descending thoracic aortic aneurysm repair (group I; n = 30), and (2) patients who had not previously undergone descending thoracic aortic aneurysm repair (group II; n = 70).

RESULTS

The distal aortic perfusion time and operation time were both longer in group I than in group II, but there was no significant difference between the two groups in total selective visceral and renal perfusion time or aortic clamp time. In-hospital mortality rates were 13% in group I and 19% in group II (p = 0.52). Major postoperative complications included paraplegia (10% of patients in group I and 4.3% of patients in group II; p = 0.36), renal failure requiring hemodialysis (20% of patients in group I and 11% of patients in group II; p = 0.35), respiratory failure (30% of patients in group I and 19% of patients in group II; p = 0.22).

CONCLUSIONS

Previously descending thoracic aortic aneurysm and redo-left thoracotomy do not adversely affect the outcome of thoracoabdominal aortic aneurysm repair.

Comparative Study of the Effect on Clinical Outcome of the Use of an Open Circuit and the Use of a Closed Circuit in Cardiopulmonary Bypass for a Graft Replacement of the Descending Thoracic or Thoracoabdominal Aorta

PURPOSE

We studied the benefits of reduced systemic heparinization in a heparin-coated cardiopulmonary bypass (CPB) system for graft replacement of the descending thoracic (TA) or thoracoabdominal aorta (TAA).

METHODS

Fifty-five patients were assigned to two groups: one group in which closed CPB circuits with reduced heparinization by elimination of the hard shell reservoir were used (group A, n = 36) and one group in which open circuits with full heparinization were used (group B, n = 19).

RESULTS

The transfusion requirement tended to be greater as the duration of CPB increased, even in group A. The incidences of renal dysfunction in two groups were not significantly different. Only the incidence of pulmonary dysfunction was significantly higher in group B. A reduction of systemic heparinization had no benefit for perioperative bleeding. In the TAA operation, the total amount of hemorrhaging in group A was greater than that in group B, but the difference was not significant.

CONCLUSIONS

No beneficial effects of the use of heparin-coated CPB circuits on the amount of perioperative bleeding and postoperative organ damage, including renal dysfunction, were found in this study. However, our findings suggest that it may be better to avoid the use of closed CPB circuits in operations with a prolonged duration of CPB, such as a TAA operation.

Retrosternal friction-induced late disruption of the anastomotic site between Bentall's valved conduit and an aortic arch graft: report of a case

We report a case of late mediastinal false aneurysm originating from disruption of the suture line between synthetic vascular grafts for aortic root and total aortic arch replacements. This aneurysm developed without any infection in a patient with Marfan's syndrome. To our knowledge, this event has never been reported before. The only possible cause of this disruption was that the monofilament suture was broken by continuous friction between the pointed anastomotic line and the sternum since the operation. The treatment options for this unusual event after extended synthetic graft replacement are discussed.

Acute type A aortic dissection with intestinal ischemia predicted by serum lactate elevation

Mesenteric ischemia can complicate acute aortic dissection. We report a case of acute type A aortic dissection with perioperative intestinal ischemia, which clinically manifested on the second postoperative day. Serial monitoring of serum lactate level by a conventional blood gas analyzer was useful for early diagnosis and for timely treatment of intestinal ischemia. In this report, monitoring of serum lactate level as a key for the successful management of intestinal ischemia is suggested.

Isolated cerebral perfusion for intraoperative cerebral malperfusion in type A aortic dissection

Cerebral malperfusion due to expansion of a false lumen can occur acutely during aortic repair when retrograde femoral perfusion is initiated. We detected this catastrophe by a rapid decrease in regional cerebral oxygenation and successfully treated it by immediate isolation of the cerebral circulation from the systemic circulation. The surgical management, including the above technique, for this rare event is described.

[Antegrade selective cerebral perfusion for extended total arch replacement using separated graft technique; reassessment from the type of aneurysms and dissections]

One hundred eighty two patients with thoracic aortic aneurysms or dissections who required total arch replacement (TAR) were operated on with separated graft technique and selective cerebral perfusion (SCP) between 1991 and 2000. These patients were divided into 4 groups according to the pathology as follows: group 1; acute type A dissection, group 2; chronic type A dissection, group 3; distal arch aneurysm and group 4; proximal arch aneurysm. For SCP, both the innominate artery and the left common carotid artery were cannulated when the patient was cooled to a rectal temperature of 22 degrees C. Hospital mortalities were 27% in group 1, 14% in group 2, 19% in group 3, and 8% in group 4. Independent predictors of hospital mortality were shock, visceral, and leg ischemia in group 1, and circulatory arrest time of the lower half body to be more than 1 hour and cardiopulmonary bypass time to be more than 5 hours in group 3. Permanent neurological complication occurred in 3% in group 1 and 8% in group 3. Hospital mortality was affected by the type of aneurysms and dissections. It is necessary to give careful consideration to the indication of TAR with SCP, especially in acute type A dissection and distal arch aneurysm.

Descending or thoracoabdominal aortic aneurysm repair without intercostal vessel reconstruction using contrast magnetic resonance angiography: report of two cases

Two high-risk patients underwent a graft replacement for descending thoracic or thoracoabdominal aortic aneurysms without the reconstruction of any intercostal and lumbar arteries. The first patient was an 81-year-old woman with asthma and renal dysfunction who was diagnosed to have a descending thoracic aortic aneurysm extending from the Th8 to Th12 level. Contrast magnetic resonance angiography (MRA) demonstrated the Adamkiewicz artery to originate from the left second lumbar artery. The second patient was a 59-year-old man with left ventricular dysfunction due to aortic and mitral stenoses who was diagnosed to have a Crawford type IV thoracoabdominal aortic aneurysm. Contrast MRA showed the Adamkiewicz artery to originate from the left ninth intercostal artery. In general, the reestablishment of the spinal cord's blood supply, whenever possible, is generally considered to be necessary in such patients to prevent spinal cord injury. However, the reimplantation of intercostal vessels is the most complex aspect of this surgical modality, and therefore, it may cause a substantial increase in the cardiopulmonary bypass time. However, at least in some cases, such as the two cases presented herein, the use of contrast MRA was found to reduce the risk in surgery for descending thoracic or thoracoabdominal aortic aneurysms by eliminating the need for any intraoperative management of the intercostal and lumbar arteries.

Less-invasive thoracic aortic aneurysm repair

To minimize surgical trauma, we performed graft replacement of a descending aortic aneurysm through a minithoracotomy (12 cm) with the use of thoracoscopy and special vascular clamps. Contrast magnetic resonance angiography can be useful for preventing postoperative paraplegia by revealing the Adamkiewicz artery. The patient was satisfied with the postoperative comfort and good cosmetic result. Further refinement of the technique and instrumentation would make this technique a valuable adjunct to conventional thoracic aortic surgery.

Significance of distal fenestration in graft replacement for chronic aortic dissection

It is recently controversial whether distal fenestration is necessary in graft replacement for chronic aortic dissection. Several groups started to try the exclusion of intimal entry by the insertion of a stent-graft as a treatment for chronic aortic dissection, while conventional surgical techniques consisted of graft replacement with distal anastomosis to both the true and false channels. It should be kept in mind that the resultant occlusion of the false lumen after obliteration of the false channel could promote spinal cord ischemia. We report a patient with delayed paraplegia after graft replacement without distal fenestration for chronic type B aortic dissection. It is possible that not all cases of chronic aortic dissection are good for stent-grafting.

[Minimal incision abdominal aortic aneurysm repair]

OBJECTIVE

The use of a limited incision for abdominal aortic aneurysm (AAA) repair was evaluated, and its outcome was analyzed in comparison to standard open repair.

PATIENTS AND METHODS

Between February 2000 and August 2001, 20 patients with an AAA underwent minimal incision repair (MINI) for tube graft implantation. The minimal skin incision was made after localization of aneurysm neck and aortic bifurcation by CT and DSA. For repair of the upper part of the AAA the abdominal incision was retracted toward the head of the patient who was in a jackknife decubitus position. Conversely, when the peripheral portion of the AAA was treated, the abdominal incision was retracted caudally with the patient in a flat or slightly bent decubitus position. The operation itself was performed using the standard conventional technique. The length of the abdominal incision was 10 cm. Clinical characteristics and in-hospital outcome of this procedure were compared to a group of patients who underwent repair of AAA by means of a standard open technique (OPEN).

RESULTS

Patients age in the MINI and OPEN groups were similar (69 +/- 11 vs. 69 +/- 9 years). However, there were significant differences between the MINI and OPEN groups in the time for starting oral intake of food (2,4 +/- 1,2 vs. 7,4 +/- 5,5 postoperative days, p = 0,003), time for starting to walk outside the room (2,2 +/- 0,7 vs. 4,6 +/- 2,2 postoperative days, p = 0,01) and operation times (197 +/- 37 vs. 294 +/- 83 min, p = 0,0004).

CONCLUSION

Minimal incision repair is technically feasible and combines the benefits of a minimal incision with those of conventional open repair, reducing patient recovery time.

[Surgical treatment of cardiovascular manifestations of Marfan syndrome]

The present study determines the effect of surgical treatment of cardiovascular manifestations of Marfan syndrome in 72 patients by 114 operations, during 34-year period. This therapy resulted in aortic root repair, aortic arch replacement, or both in 78, mitral valve repair in 9, descending thoracic aortic replacement in 14, thoracoabdominal aortic replacement in 10, and abdominal aortic replacement in 6, including total aortic replacement in 4 and nearly total aortic replacement in 4 patients. Fusiform aneurysms were present in the the ascending aorta in 37, the aortic arch in 2, the thoracoabdominal aorta in 2, and the abdominal aorta in 6 patients. Aortic dissection occurred in 40 (55.6%), including type A aortic dissection in 29 patients. Aortic root repair included separate valve-graft in 8, Bentall composite valve-graft in 25, composite valve-graft with button technique in 26, composite valve-graft with interposition graft technique in 10, and valve sparing procedure in 5 patients. The overall early (30-day) mortality was 7.9%. The early survival was 75% in separate valve-graft procedure and 99.2% in composite valve-graft procedure. Late coronary dehiscence did not occur in the patients with Bentall technique in which the reattachments of coronary ostia were performed in 2 layers, but occurred in 50% of patients with the coronary anastomoses in 1 layer. Aortic valve regurgitation relapsed in 2 of the 5 patients with valve sparing procedure. Event free rate for the patients with composite valve-graft using button technique was 81.1% at 10 years. There were 14 late deaths; dissection or rupture of the residual aorta, composite graft endocarditis and cardiac failure were the principle causes of late deaths. In conclusion, Marfan patients with cardiovascular diseases can undergo surgical treatment with a low operative risk and low morbidity. Although late endocarditis remains a serious problem, we believe that Marfan syndrome is a contraindication for valve sparing procedure. Because of the potential for late dissection or aneurysm in other areas of the aorta, patients with Marfan syndrome should have serial computed tomographic scans indefinitely.

Thoracoabdominal or descending aortic aneurysm repair after preoperative demonstration of the Adamkiewicz artery by magnetic resonance angiography

OBJECTIVE

The outcome of thoracoabdominal or descending aortic aneurysm repair after preoperative demonstration of the artery of Adamkiewicz (ARM) by magnetic resonance angiography (MRA) was investigated.

METHODS

Between January 2000 and December 2001, 40 consecutive patients who had aneurysms of the thoracoabdominal or descending aorta underwent preoperative MRA to visualize the ARM. Thirty-two patients underwent replacement of the aneurysms, and 25 patients (TAAA, 11; TAA, 14) underwent replacement of the aneurysms with preoperative detection of the ARM. Only intercostal or lumbar arteries in aneurysms, which were detected as the origin of the ARM, were reattached to the graft. The results of thoracoabdominal aortic aneurysm operations in 11 patients in whom the ARM was preoperatively detected (group I) were compared with the results of TAAA operations in 26 patients in whom the ARM was not preoperatively detected (group II).

RESULTS

MRA demonstrated the ARM in 29 (73%) of the 40 patients. The laterality of the arteries originated from the left side in 29 (100%) and between Th9 and Th12 in 25 (86%), between Th9 and L1 in 28 (97%) of the 29 patients. No spinal cord injury occurred in patients (TAAA and TAA) in whom the ARM had been preoperatively detected. Major complications following TAAA operations included paraplegia (0% in group I and 8% in group II), respiratory failure (9% in group I and 23% in group II), and renal failure requiring hemodialysis (18% in group I and 22% in group II). Operation times were 439+/-99 min in group I and 620+/-200 min in group II (P=0.008).

CONCLUSIONS

Preoperative detection of the ARM is possible by MRA and is very useful for reducing the incidence of ischemic injury of the spinal cord and for reducing the time of an operation for repair of an aneurysm of the thoracoabdominal or descending aorta.