Transluminal placement of endovascular stent-grafts for the treatment of type A aortic dissection with an entry tear in the descending thoracic aorta

PURPOSE

The current therapy for type A aortic dissection is ascending aortic replacement. Operative mortality and morbidity rates have been markedly improved because of recent advances in surgical techniques and anesthesiology. However, type A aortic dissection with an entry tear in the descending thoracic aorta is still a surgical challenge because of the need for extensive aortic replacement.

METHODS

Ten patients with type A aortic dissection were treated with endovascular stent-grafts. The false lumen of the ascending aorta was patent in five patients, and it was thrombosed in the other five patients. The entry tears were located in the descending thoracic aorta in all cases. Seven patients had acute dissection, and three patients had subacute dissection. Four patients had pericardial effusion. Stent-grafts were fabricated from expanded polytetrafluoroethylene and Z-stents.

RESULTS

Entry closure was achieved in all patients. Complete thrombosis of the false lumen of the ascending aorta was observed after stent-grafting in all patients. A second stent-graft was required in two patients to obtain complete thrombosis of the false lumen of the descending thoracic aorta. No procedure-related complications were observed, with the exception of a minor stroke in one patient. During a mean follow-up period of 20 months, no aortic rupture or aneurysm formation was noted in either the ascending or descending thoracic aorta, and all patients were alive and doing well. The abdominal aortic aneurysm enlarged after stent-grafting in one patient, and this was treated by closing the fenestrations of the abdominal aorta with stent-grafts.

CONCLUSION

Stent-graft repair of aortic dissection with an entry tear in the descending thoracic aorta is a safe and effective method and may be an alternative to surgical graft replacement in highly selected patients.

Coronary artery aneurysm in a patient with Marfan syndrome

True aneurysm of the coronary artery in Marfan syndrome is very rare. We present a patient with Marfan syndrome who had aneurysms from the ascending aorta to the thoracoabdominal aorta and a large aneurysm of the left main coronary artery after an original Bentall operation. Prosthetic graft replacement of total aorta, coronary artery bypass grafting, and removal of the aneurysm of the left main coronary artery were successfully performed.

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.

Mr flow measurement in the internal mammary artery-to-coronary artery bypass graft: comparison with graft stenosis at radiographic angiography

PURPOSE

To evaluate the sensitivity and specificity of breath-hold magnetic resonance (MR) flow measurement for detection of significant stenosis in internal mammary artery bypass grafts.

MATERIALS AND METHODS

Twenty-six consecutive patients who had undergone coronary artery bypass surgery were examined. Breath-hold velocity-encoded cine MR images were obtained at the midpoint of the internal mammary artery between its origin from the subclavian artery and the distal anastomosis to the left anterior descending artery.

RESULTS

MR images were obtained successfully in 24 patients. At conventional angiography, no significant stenosis was observed in 17 patients (group A), and significant stenosis (diameter > 70%) was observed in seven patients (group B). The mean diastolic-to-systolic peak velocity ratio in group B (0.61 +/- 0.44 [SD]) was significantly lower than that in group A (1.88 +/- 0.96; P <.01). Evaluation of graft stenosis with the diastolic-to-systolic peak velocity ratio revealed a sensitivity of 86% and a specificity of 88%. The mean blood flow rate at baseline in group B (16.9 mL/min +/- 5.5) was significantly lower than that in group A (79.8 mL/min +/- 38.2; P <.01). The sensitivity and specificity of MR blood flow measurement in predicting significant stenosis were 86% and 94%, respectively. The mean pharmacologic flow reserve ratios were 2.00 +/- 1.43 in group A and 1.39 +/- 1.46 in group B (P >.05).

CONCLUSION

Fast MR blood flow measurement at baseline is highly useful for predicting significant stenosis in internal mammary arterial grafts.

Treatment of chronic aortic dissection by transluminal endovascular stent-graft placement: preliminary results

PURPOSE

To investigate efficacy of stent-graft repair for the treatment of patients with chronic aortic dissection.

MATERIALS AND METHODS

Fifteen patients with chronic aortic dissection were treated with endovascular stent-grafts. Entry tears were located in the descending thoracic aorta in all patients. The mean maximum diameter of the descending thoracic aorta was 47 mm +/- 8. The mean diameter of the true lumen at the same level was 20 mm +/- 5. The mean interval between diagnosis and stent-graft procedure was 32 months +/- 91. Stent-grafts were fabricated from expanded polytetrafluoroethylene and Z-stents.

RESULTS

Stent-grafts were placed successfully in all patients. Two stent-grafts were required in one patient. Entry closure and thrombosis of the false lumen of the descending thoracic aorta were also achieved in all patients. No procedure-related complications were observed except for postimplantation syndrome, including fever and leukocytosis. The diameter of the true lumen was significantly increased (mean, 31 mm +/- 6) at the level of the descending thoracic aorta (P <.01) and the diameter of the aorta was significantly decreased (mean, 44 mm +/- 8) at the same level (P <.01). There were no deaths and no instances of aortic rupture during the subsequent average follow-up period of 24 months. Secondary stent-graft procedures were required to treat the abdominal component of dissection during follow-up in one patient.

CONCLUSIONS

Stent-graft repair of chronic aortic dissection is a safe and effective method and may be an alternative to surgical graft replacement in selected patients. However, further evaluation is mandatory before this method is widely employed.

Synchronous primary lung carcinoma and lung metastasis from extrathoracic carcinoma

We present the cases of 2 patients in whom primary lung cancer was found unexpectedly when pulmonary resection was performed for metastatic lung cancer. The possibility of combined primary and metastatic carcinoma should be considered in patients with a diagnosis of multiple pulmonary metastases from extrathoracic tumor.

[Total removal of infected pacemaker lead under cardiopulmonary bypass in a case of endocarditis, bacteremia and lung abscess]

A 60-year-old man, who had undergone implantation of a transvenous pacemaker system on the left chest wall for sick sinus syndrome 19 years ago, was admitted because of endocarditis with septicemia and lung abscess 2 months after reimplantation of the generator. His blood culture revealed Staphylococcus aureus. Following debridement of the infected pacemaker pocket and antibiotics therapy, we tried to remove the pacemaker system under cardiopulmonary bypass 1 month after admission. In intraoperative inspection, the electrodes had become firmly encased with fibrous tissue within the tricuspid valve and the right ventricle. After the operation, antibiotic therapy was performed for 4 weeks. His postoperative course was uneventful. Patients with pacemaker infection should undergo aggressive total removal of the pacemaker system, particularly incase with endocarditis and bacteremia.

The effects of single lung transplantation in rats with monocrotaline-induced pulmonary hypertension

Acute haemodynamic change after single lung transplantation for primary pulmonary hypertension was evaluated using a rat transplantation model. Inbred Fisher 344 rats were administered with 40 mg/kg monocrotaline in order to induce pulmonary hypertension. The rats whose mean pulmonary arterial pressure (PAP) was over 30.0 mm Hg received a left lung isograft from a normal donor after right heart catheterization. In the control group, PAP increased after single lung transplantation. On the other hand, in the pulmonary hypertensive group, PAP was significantly decreased 60 min after the transplantation, but 3 and 6 h after the transplantation, the PAP significantly increased again. On the day after the operation, it again decreased significantly. Left-to-right lung blood flow ratio was significantly increased in rats with pulmonary hypertension compared to rats with normal pulmonary pressure on both the 1st and 3rd postoperative days. The oedema of the grafted lung was more severe in the pulmonary hypertensive group than in the control group in the acute phase. In conclusion, single lung transplantation for pulmonary hypertension shifted pulmonary blood perfusion to the grafted lung and this shift made pulmonary oedema of the grafts more severe in the acute phase. These oedematous changes, which were more pronounced in the grafts in the pulmonary hypertensive rats, might have contributed to the transient rise in PAP in those rats after single lung transplantation.

[A case of surgically treated left atrial myxoma following acute multiple embolism including cerebral embolism]

The patient was a 59-year-old female who was admitted to the hospital due to acute pain of bilateral legs, a numbness of right hand and anarthria. Angiography of extremities revealed total occlusion of right ulnar artery, left radial artery and bilateral popliteal arteries. Brain MRI revealed multiple small infarctions. Echocardiography revealed a mass in the left atrium. She was diagnosed as multiple embolism including cerebral embolism caused by left atrial myxoma. Open heart surgery immediately after the attack is generally considered contraindicated due to problems of hemorrhagic infarction or brain edema. But, relapse of embolism may deteriorate the condition and miss the timing of surgery. Thus we performed removal of left atrial myxoma 4 days after the attack. The postoperative course was uneventful. This is a few report about open heart surgery immediately after the attack. We report about the indication and the optimal timing of open heart surgery following cerebral embolism.

[The perioperative management for the patients to undergo open heart surgery with chronic renal failure]

From January, 1996 to December, 1999, eight patients with chronic renal failure received open heart surgery. They consists of six males and two females aged between 45 and 72 with a mean of 59.6. The duration of hemodialysis was 4.0 years in a mean. Seven of them had isolated coronary artery bypass grafting (CABG), one of them had CABG and aortic valve replacement. All patients were dialysed dialy two days before operation. Intraoperative hemodialysis (HD) was used in all patients. In recent six patients extracorporeal ultrafiltration methods (ECUM) were also performed intraoperatively in addition to HD. In postoperatively continuous hemodiafiltration (CHDF) has been preferred to HD in all patients, and nafamostat mesilate is a useful anticoagulation agent to prevent postoperative bleeding complications. The duration of CHDF was 3.2 days in a mean (the shortest for one day and the longest for eight days). When the circulatory situation were stable, HD was performed on early postoperative day. One patients died of low output syndrome and multiple organ failure. We reported problems in perioperative management of patients with chronic renal failure and our protocol.

Surgical repair of extracardiac unruptured acquired Valsalva aneurysms

Two cases of extracardiac unruptured Valsalva aneurysms due to rare causes are reported. One patient had been suffering from hyper eosinophilic syndrome. Operative corrections consisted of total replacement of the aortic root. The other patient had an aneurysm of just noncoronary sinus of Valsalva and a dilated ascending aorta due to cystic mucoid degeneration. Replacement of the ascending aorta with patch closure for the aneurysm was successfully performed.

Less invasive therapy using endovascular stent graft repair and video-assisted thoracoscopic surgery for ruptured acute aortic dissection

We report a 75-year-old man with a ruptured acute thoracic aortic dissecting hematoma treated using endovascular stent grafting and video-assisted thoracoscopic surgery. This less invasive therapy is a good therapeutic option even in ruptured acute aortic dissections, particularly given the difficulty of surgery.

Long-term follow-up after Carpentier-Edwards ring annuloplasty for tricuspid regurgitation

BACKGROUND

Use of flexible rings for tricuspid ring annuloplasty is becoming popular. This study was undertaken to evaluate Carpentier-Edwards (C-E) rigid ring annuloplasty for tricuspid regurgitation (TR), secondary to mitral valve disease and clinical outcome on a long-term basis.

METHODS

From December 1985 to March 1996, 45 patients with secondary TR underwent C-E ring annuloplasty. Thirty-nine patients (95.1%) were in New York Heart Association (NYHA) functional class III or IV. The mean follow-up was 96.7+/-48.5 months or 362.6 patient-years.

RESULTS

There were three in-hospital and nine late deaths that were not related to tricuspid annuloplasty. Actuarial survival at 10 years was 68.3%. Echocardiographic studies showed that TR was well controlled within grade 2+ in all survivors. Residual pulmonary hypertension (PH) was recognized in 9 of 21 patients (42.9%) with preoperative PH, however, no TR was seen in 6 patients. A TR grade of 2+ was observed in 3 patients. Thirty of the total survivors (96.8%) were in NYHA class I and II, but 1 patient was in NYHA class III. The actuarial rate of freedom from tricuspid valve reoperation after 10 years was 97.5%.

CONCLUSIONS

C-E ring annuloplasty is acceptable for repair of secondary TR and improvement in clinical status on a long-term basis.

The role of cyclosporine A and interleukin-2 in obliterative airway disease in a rat tracheal transplant model

The pathogenesis of obliterative bronchiolitis (OB) following lung and heart-lung transplantation remains unclear. We evaluated the role of CsA and IL-2 on the development of obliterative airway disease (OAD) by administrating exogenous IL-2 in a CsA-treated rat tracheal transplant model. Tracheal grafts were implanted into the peritoneal cavity from Brown Norway (BN) to BN rats or to Lewis (LEW) rats. Allotransplant: No treatment was given in group 1. Short-term CsA (25 mg/kg, i.m. on POD 2 and 3) was used in group 2. Group 3 was treated with long-term CsA (25 mg/kg, i.m. on POD 2 and 3, followed by 5 mg/kg on POD 4 to 27). Administration of IL-2 (300, 000 IU/kg, i.p. on POD 15 to 19 and 22 to 26) was performed to long-term CsA treated rats in group 4. Isotransplant: No treatment was given to group 5, group 6 was treated with IL-2 (same regimen as in group 4). Grafts were harvested at different time points after Tx for histological assessment. No luminal obliteration was observed in group 5 and 6. Complete luminal obliteration was noted 4 weeks after Tx in group 1. In group 2 and 3, obliterative lesion occurred 4-6 weeks after CsA withdrawal. IL-2 increased epithelial loss, lymphocytic infiltration, and obliterative changes in group 4. Our results suggest that OAD is an immune mediated disorder. Furthermore, administration of exogenous IL-2 might be able to abrogate the protection from OAD by CsA therapy.

Strategy for pulmonary atresia and intact ventricular septum

Pulmonary atresia with an intact ventricular septum is characterized by varying degrees of right ventricular cavity hypoplasia. This factor is critical in determining the most appropriate surgical approach for each patient. We describe a patient who underwent definitive biventricular surgical repair in early infancy. We used an atrial septal defect patch with a one-way valve and performed a right ventricular overhaul after a balloon valvotomy.

Atopic dermatitis as a risk factor for acute native valve endocarditis

Colonization of Staphylococcus aureus is commonly observed in skin lesions of atopic dermatitis (AD) patients, and scratching of the pruritic lesions may lead to reiterative bacteremia. It is possible that acute native valve endocarditis may develop in a patient with uncontrolled AD; the latter condition may be a risk factor for the former. We report two cases of acute aortic and/or mitral valve endocarditis complicated with recurrent cutaneous infections caused by severe AD. The patients underwent successful surgical treatment of the heart lesions, plus intensive postoperative antibiotics and skin treatment for AD.

Aortoesophageal fistula-relief of massive hematemesis with an endovascular stent-graft

A 59-year-old man with an esophageal carcinoma developed massive hematemesis due to aortoesophageal fistula after irradiation therapy reached 58 Gy. Emergent treatment with an endovascular stent-graft was successfully performed and the patient followed an uneventful course until he died of pneumonia 4.5 months later, which was caused by a tracheoesophageal fistula. Stent-graft repair is a safe and effective method to treat aortoesophageal fistula and may be an alternative to surgical resection.

[The effects of intravenous milrinone for the patient undergoing CABG]

The hemodynamic effects of intravenous infusion of milrinone were evaluated in 25 patients undergoing CABG using an internal mammary artery graft. Milrinone was administered to 9 patients at the time of weaning from cardiopulmonary bypass, at a dosage of 3 to 5 micrograms/kg/min. Postoperative cardiac function was compared in this group versus the other 17 patients who were treated without milrinone. We determined such parameters as cardiac index, wedge pressure and mean pulmonary pressure. Our findings did not show any significant difference between the 2 groups. We also studied a subject of low-output patients (EF < 0.5). In the patients with low-cardiac output, the use of milrinone in addition to standard postoperative administration of low-dose dopamine reduced mean pulmonary pressure and wedge pressure. Thus, milrinone not only improved the left ventricular function, but also expanded the pulmonary vascular bed.

Five-year follow-up of valve replacement with the Jyros bileaflet mechanical valve

Jyros bileaflet rotating valves were implanted as a clinical trial conducted in Japan, and the 5-year results were assessed. Nineteen patients underwent implantation of the valves: 14 in the mitral and 5 in the aortic position. The mean follow-up period was 65.4+/-15.7 months. There was 1 case of late death due to fatal arrhythmia and another case of cerebral thromboembolism (1.0% per patient year). All survivors were in New York Heart Association class I. On the early postoperative cinefluorography, 8 valves (42.1%) showed rotation of the leaflets. However, in the latest assessment 6 valves (33.3%) showed rotation, some valves had stopped rotation, and others had started to rotate during the follow-up period. The Jyros valve functions effectively, similar to other bileaflet valves. However, because the correlation between thromboembolism and the rotation mechanism is not clear, further follow-up of our patients and more implant studies are necessary to elucidate this issue.

Biocompatibility of silicone-coated oxygenator in cardiopulmonary bypass

BACKGROUND

This study was designed to analyze the biocompatibility of silicone-coated oxygenators using inflammatory response as the outcome measure, and to investigate whether the silicone-coated oxygenators perform better in terms of postoperative organ dysfunction.

METHODS

The 32 patients who underwent cardiopulmonary bypass (CPB) were divided into 3 groups: group A (n = 10), heparin-coated circuit with silicone-coated oxygenator; group B (n = 11), whole heparin-coated circuit; and group C (n = 11), whole untreated circuit. The plasma concentrations of the proinflammatory markers, made of inflammatory cytokines (tumor necrosis factor-alpha, interleukin-1beta, interleukin-6, interleukin-8), terminal complement complex (C5b-9), and polymorphonuclear elastase (PMN-E), were measured by enzyme-linked immunosorbant assay.

RESULTS

All proinflammatory markers were significantly lower in groups A and B than in group C, especially C5b-9 and PMN-E concentrations, which were significantly lower in group A than in group B. The alveolar-arterial oxygen gradients (A-aDO2) and the respiratory index were significantly better in group A than in group C. In group B, however, only the A-aDO2 was significantly better than in group C. The duration of intubation and the length of stay in the intensive care unit stay were significantly shorter in groups A and B than in group C.

CONCLUSIONS

Silicone-coated oxygenators are biocompatible and prevent postoperative organ dysfunction.