Multiple Re-entry Closures After TEVAR for Ruptured Chronic Post-dissection Thoraco-abdominal Aortic Aneurysm.

INTRODUCTION: Although thoracic endovascular aortic repair (TEVAR) has become a promising treatment for complicated acute type B dissection, its role in treating chronic post-dissection thoraco-abdominal aortic aneurysm (TAA) is still limited owing to persistent retrograde flow into the false lumen (FL) through abdominal or iliac re-entry tears. REPORT: A case of chronic post-dissection TAA treatment, in which a dilated descending FL ruptured into the left thorax, is described. The primary entry tear was closed by emergency TEVAR and multiple abdominal re-entries were closed by EVAR. In addition, major re-entries at the detached right renal artery and iliac bifurcation were closed using covered stents. To close re-entries as far as possible, EVAR was carried out using the chimney technique, and additional aortic extenders were placed above the coeliac artery. A few re-entries remained, but complete FL thrombosis of the rupture site was achieved. Follow-up computed tomography showed significant shrinkage of the FL. DISCUSSION: In treating post-dissection TAA, entry closure by TEVAR is sometimes insufficient, owing to persistent retrograde flow into the FL from abdominal or iliac re-entries. Adjunctive techniques are needed to close these distal re-entries to obtain complete FL exclusion, especially in rupture cases. Recently, encouraging results of complete coverage of the thoraco-abdominal aorta with fenestrated or branched endografts have been reported; however, the widespread employment of such techniques appears to be limited owing to technical difficulties. The present method with multiple re-entry closures using off the shelf and immediately available devices is an alternative for the endovascular treatment of post-dissection TAA, especially in the emergency setting.

[Spinal cord protection during thoracoabdominal aortic aneurysm repair; efficacy of distal aortic perfusion and segmental aortic clamping].

Despite improvement in adjuncts for thoracoabdominal aortic aneurysms (TAAA) repairs, many devastating complications remains after the surgery. Our experience with these aneurysms has been reviewed in order to identify those methods at risk of major morbidity, as well as which further improvements required. During last 16 years, 53 consecutive patients were operated on TAAA. The mean age was 58 years. Twenty patients had dissecting aneurysms and 13 patients had had prior aortic surgery. A femoro-femoral bypass was used to maintain distal aortic perfusion in most patients. Reimplantation of intercostal or lumbar arteries under the multi-segmental aortic clamping is consistent in our technique. Motor evoked potentials (MEP) were measured to monitor spinal cord protection since 2000. The hospital mortality was 9.4% (5/53), 22.2% (2/9) for emergency operation and 15.4% (2/13) for patients with prior aortic surgery. The mortality for the first and elective operations was 3.2% (1/31). No any neurologic dysfunction was observed in all patients including the hospital deaths. In view of clinical results, our adjuncts and techniques are useful for prevention of spinal cord ischemia during the TAAA surgery.

Blood distribution to the anterior spinal artery from each segment of intercostal and lumbar arteries.

AIM: Prevention of paraplegia, a serious complication of surgery for thoracoabdominal aortic aneurysm, has been well documented. However no assured prophylaxis against this complication has yet been found. Spinal ischemia is believed to be the major cause of paraplegia. We conducted an experimental study to define the development of paraplegia with regard to the blood supply to the spinal cord. METHODS: A porcine model was used to evaluate blood distribution to the anterior spinal artery. Colored silastic agent was selectively injected into the intercostal and lumbar arteries, and distribution to the anterior spinal artery was evaluated on 50 animals. The intercostal and lumbar arteries were ligated in the segments where the blood supply to the anterior spinal artery would be interrupted. Whether or not paraplegia developed was checked 2 days later. RESULTS: Colored silastic agent arrived at the anterior spinal artery from all segments of the 8th intercostal to 4th lumbar arteries. Two of 9 pigs (22.2%) that underwent ligation of the segments from the 9th intercostal to 2(nd) lumbar artery suffered paraplegia. In 3 non-paraplegic pigs, colored silastic agent injected into the preserved arteries was found to have covered a wider range. CONCLUSION: All the intercostal and lumbar arteries supplied blood to the anterior spinal artery. When large segments of intercostal and lumbar arteries were ligated, the blood flow from the preserved segments acquired increased dominance. The possibility exists that any intercostal and lumbar artery can supply blood to the spinal cord and become collateral circulation to the anterior spinal artery.

[Impact of multi-segmental aortic clamping and distal aortic perfusion on the prevention of postoperative paraplegia during thoracoabdominal aortic graft replacement]. / Multisegmentale Aortenabklemmung und distale Aortenperfusion zur Verhinderung der postoperativen Paraplegie bei thorakoabdomineller Aortenprothesenimplantation.

OBJECTIVE: We present the impact of multisegmental aortic clamping under distal aortic perfusion and segmental artery reimplantation on the prevention of postoperative paraplegia during thoracoabdominal aortic graft replacement. PATIENTS: During the last 14 years in 47 patients (age range: 22 to 82 years; average: 57,9 +/- 13,2 years; 16 females and 31 males) with thoracoabdominal aortic aneurysm a graft replacement was performed with adjuncts of normothermic partial bypass and multisegmental aortic clamping. As many patent segmental arteries as possible were reimplanted. RESULTS: Five patients died during hospitalization, for an in-hospital mortality rate of 10,6 %. In the elective patients (n = 40), the hospital mortality rate was 7,5 %. The average number of segmental aortic clampings per patient was 2,83 +/- 1,19 times. In 39 patients (82,9 %), 117 segmental arteries were reimplanted or preserved by beveled anastomosis. Eighty-three out of 117 segmental arteries (70,9 %) were located between TH9 and L2. Postoperative paraplegia/paraparesis did not occur in any patient. CONCLUSION: In view of our results reimplantation of as many segmental arteries as possible under multisegmental aortic clamping with adequate distal aortic perfusion can be recommended for effective prevention of spinal cord ischemia in TAAA surgery.

One-stage operation for descending thoracic aortic aneurysm and left lung cancer: a case report.

We performed concomitant graft replacement for descending thoracic aortic aneurysm and pulmonary resection for squamous cell carcinoma of the left upper lobe in a 79-year-old man. The tumor reached the parietal pleura. No distance metastasis was found, and the tumor was diagnosed preoperatively as a stage IIB (N0, M0, T3) tumor. The descending thoracic aortic aneurysm was saccular, with greatest diameter being 55 mm, and extending from TH5 to TH8. A left upper lobectomy was performed, and after irrigation with a large volume of saline diluted with povidone iodine, graft replacement for the aortic aneurysm was performed under femoro-femoral partial bypass. To prevent postoperative graft infection, the greater omentum was dissected and placed over the resected pulmonary hilum and the graft. The patient's postoperative course was uneventful. There was no sign of infection, and the patient was discharged 1 month after surgery. Artificial graft wrapping with the greater omentum was useful for the prevention of the postoperative graft infection in this case of surgical treatment of lung cancer and descending thoracic aortic aneurysm.

Management of the heart rate during coronary artery bypass grafting on the beating heart: newly devised methods of decreasing heart rate--a preliminary report-.

BACKGROUND: To develop new methods for achieving bradycardia, we studied the feasibility of producing transient, reversible bradycardia with atrial stimulation and cooling of the sinoatrial node. METHODS: In an animal study, the atrium was stimulated electrically during the refractory period of the atrioventricular node. Alternatively, an area of the sinoatrial node was cooled regionally. The two methods were also performed in combination. In a clinical study, atrial stimulation was applied in seven consecutive patients who underwent coronary artery bypass grafting (CABG). RESULTS: In the animal study, atrial stimulation was effective only when 2 mg/kg of diltiazem was administered. Such atrial stimulation decreased heart rate (beats/minute) from 95.8+/-16.9 to 64.2+/-20.0 (the average reduction from the control value 66.1+/-10.3%). Cooling the sinoatrial node decreased heart rate, and was effective with or without administration of diltiazem. Heart rate was decreased from 156.6 31.7 to 110.7+/-21.7 (average reduction from control value 71.3+/-9.2%) before using diltiazem and from 102.0+/-11.9 to 63.5+/-13.9 (average reduction from control value 62.0+/-10.4%) after administration of diltiazem. By combining the two methods, heart rate was decreased from 102.0+/-12.3 to 44.6+/-9.1 (average reduction from control value 43.5+/-6.3%). In our clinical study, the atrial stimulation method was effective. CONCLUSION: Atrial stimulation or regional cooling of the sinoatrial node slowed the heart rate. By combining the two methods, the heart rate was slowed to 40. Clinically, atrial stimulation was effective in CABG patients.

[Evaluation of the results of the combined maze procedure for chronic atrial fibrillation with organic heart disease].

To examine the surgical indications and the results of the maze procedure, we reviewed 30 cases who underwent the maze procedure concomitantly with other open heart surgery from October 1995 to October 1997.: the average age was 60.9 years (37 to 75 years) and mean follow up period was 12.3 months (1 to 25 months). The modified maze procedure described by Kosakai and associates was applied in all patients. Twenty one patients (72.4%) regained atrial rhythm and eight patients (27.6%) sustained atrial fibrillation in the follow up periods. The left atrial diameter measured by echocardiography and cardiothoracic ratio were significantly larger in the latter group of patients, compared with those who recovered normal sinus rhythm (63.8 +/- 19.5 versus 51.2 +/- 7.8 mm and 67.7 +/- 8.1 versus 59.2 +/- 5.4%). In order to perform the combined maze procedure, cardiac arrest time and cardiopulmonary bypass time were extended for 56.9 minutes and 65.9 minutes, respectively, compared with the cases without a maze procedure. Four patients (brady atrial fibrillation 2, brady junctional rhythm 1, and complete AV block 1) required permanent pacemaker implantation. There was no operative death, but one patient who underwent the maze procedure and AVR + MAP + TAP died after 4 months due to pulmonary infection, sepsis and multiple organ dysfunction. This patient had shown low output syndrome for 3 days postoperatively. Having considered the data that the preoperative ejection fraction was 51%, cardiopulmonary bypass and cardiac arrest time were 200 min and 165 min respectively, occurrence of low cardiac output had been influenced by prolonged aortic cross-clamp. No late deaths have been observed in follow up period. In conclusion, maze procedure should not be performed in patients who have enlarged left atrium or complex cases requiring relatively longer operative time.

[Mitral valve regurgitation with anterior mitral leaflet chordal rupture or elongation--repair using the flip-over technique].

Repair of prolapsed anterior mitral leaflet has remained technically difficult. The purpose of this study was to assess the clinical results after using the flip-over technique for patients with anterior mitral leaflet prolapse due to dhordal rupture or elongation. Between January 1993 and September 1997, fifteen adult patients with pure mitral valve regurgitation (MR) due to prolapse of the anterior mitral leaflet underwent repair using the flip-over technique. The indication for this procedure were; 1) all mitral structures except the prolapsed area must appear to be intact, and 2) the corresponding chordae attached to the posterior leaflet should be sufficiently strong to be transferred to the anterior leaflet. The prognoses following this technique were retrospectively studied to assess the early and mid-term clinical outcome of this procedure. Follow up was complete in all patients and ranged from 2 to 56 months (with a mean of 25 +/- 17.9 months). There was no hospital death, None required reoperation. One patient died because of acute recurrent MR during follow-up. No other complication was experienced. Doppler echocardiographic studies at the final follow-up showed less than mild regurgitation in 11 (78.6%) of the 14 surviving patients. We believe that this procedure was effective for that the obtained repair of a prolapsed anterior mitral valve and early and mid-term clinical outcome from this procedure has been satisfactory.

[An evaluation of cases carried out by both root reconstruction using Carrel patch method and concomitant procedure].

During the past 7 years from January 1991 to November 1997, we experienced 31 cases of aortic root reconstruction utilizing Carrel patch method. Concomitant procedure were performed in 9 cases of them due to another cardiovascular disease. Complicated cardiovascular disease included 3 cases of ischemic heart disease, 3 cases mitral regurgitation and one case of Aortic arch aneurysm. Several concomitant procedures were performed; 5 cases of CABG, 2 cases of mitral annuloplasty, one case of CABG with mitral valve replacement and one case of aortic arch replacement. The mean extra corporeal circulation time was 190.6 +/- 39.3 minutes and aortic clamp time was 147.8 +/- 34.2 minutes in these 9 cases. There were no significant differences of operative results between the simple root reconstruction group and the concomitant procedure group. We concluded that the aortic root reconstruction using the Carrel patch method has few complications. Although further long-term follow-up is required, our experiences suggest that the aortic root reconstruction with the concomitant procedure can be carry out safely with the aid of appropriate assistance method.

[The propriety of bilateral internal thoracic artery grafting in women].

In our institution, the exclusion criteria of the bilateral internal thoracic artery (BITA) grafting include age over 70 years old, obesity, severe diabetes, renal dysfunction and poor preoperative physical activity. The objective of this study is to evaluate propriety of the use of bilateral internal thoracic artery for coronary artery bypass grafting (CABG) in women. Clinical outcome of female patients who underwent BITA grafting (group B-F; n = 50) was compared with that of female patients who underwent single internal thoracic artery grafting (group S; n = 50). In addition, clinical outcome of the male patients who underwent BITA grafting (group B-M; n = 50) was compared with that of group B-F. Between group B-F and S, the age, prevalence of obesity and that of renal dysfunction were significantly different, which was predictable because of the group selection according to the criteria. However, the prevalence of previous myocardial infarction and that of left ventricular dysfunction and the extent of coronary artery disease were not significantly different. Whereas, between group B-F and B-M, preoperative factors were not significantly different except the body size. Intraoperative technical factors, such no of grafts, aortic cross clamp time, cardiopulmonary bypass time, rate of complete revascularization, were not significantly different. In comparison of group B-F with group B-M, the site of anastomosis with arterial grafts were not significantly different. Patency rate of arterial and venous grafts two week after operation was not significantly different. Either postoperative complications, such as reoperation for bleeding, wound complication, low output syndrome, renal dysfunction etc, were not significantly different. One patient (2%) in group B-F and 1 patient (2%) in group B-M died in the hospital (p > 0.05). In summary, BITA can be a viable conduit of choice for CABG in female patients as well as that in male patients. Criteria of the use of BITA is recommended to exclude preoperative risk factors above-mentioned.

[Cardiac surgery in patients with chronic renal failure on maintenance dialysis].

From July 1988 through August 1996, 54 patients with chronic renal failure (CRF) on maintenance dialysis (50 hemodialysis = HD, and 4 continuous ambulatory peritoneal dialysis) have undergone some sort of surgical procedure requiring the use of extra corporeal circulation (ECC); 42 patients underwent isolated coronary artery bypass grafting (CABG), 8 valve replacement, 3 combined procedures and 1 correction of a congenital heart defect. The protocol called for maintenance dialysis on the day before surgery, large volume hemofiltration (HF) during the ECC period, postoperative K+ management with dextrose-insulin if required, and resumption of whatever preoperative maintenance dialysis 24 hours after the operative procedure. The mean diafiltrate volume of HF was 7963 +/- 2688 ml which was replaced with 6342 +/- 2748 ml. No patient required emergency HD before the resumption of the maintenance dialysis, although in 40% of the early patients HD was added on the second postoperative day. However as experience was gained, in the latter 60% of patients resumption of maintenance dialysis (HD 3 times a week) was thought to be sufficient. The incidence of calcification in patients with CRF is higher not only of involved coronary artery segments (4.5 +/- 2.3 segments; AHA coronary classification) than its counterpart without CRF, but also of the ascending aorta which mandated modifications of the technique in 6 patients (operation under ventricular fibrillation, cannulation access other than ascending aorta). The use of arterial in situ conduits for CABG was also thought to be advantageous, and the left internal thoracic artery combined to the gastro-epiploic artery was used in 11 patients (26.2%). Four patients died) (7.4%): 2 from arrhythmia, one from intestinal necrosis and one from multiple cerebral infarction. Thus we conclude that the outlined protocol is quite effective in controlling fluid and electrolyte balance in patients on maintenance dialysis allowing to undertake surgical procedures requiring the use of extra corporeal circulation relatively safely.