Supravalvular aortic stenosis in aortic dissection

Supravalvular aortic stenosis is a rare complication of aortic dissection. We report on echocardiographic and magnetic resonance observations in 2 cases of aortic dissection with false lumen thrombosis of the ascending aorta and severe narrowing of the true lumen.     

Systolic aortic valve compression from partial dehiscence of an aortic valve homograft

Implantation of valve prostheses provide improvement of symptoms and prolongation of life in selected patients with valvular heart disease. Meticulous follow-up of patients after valve surgery is essential as complications of valve failure, valve dehiscence, valve thrombosis, and infection may occur. The major mode of failure of aortic valve homografts is valve regurgitation, which is readily detected by physical examination. We report a case of left ventricular outflow obstruction after implantation of an aortic valve homograft.     

Thrombus formation on a calcific and severely stenotic bicuspid aortic valve

We report on a case of thrombus formation on a native bicuspid aortic valve, which was found during an elective operation for aortic valve replacement. Although no apparent predisposing cause of thrombosis could be ascertained, severe calcific stenosis of the bicuspid valve and cardiac catheterization may have played a role. The patient is in excellent condition 9 months after the operation.     

Detection of thrombotic cuspal obstruction of an aortic bioprosthesis with transesophageal echocardiography

Bioprosthetic thrombotic obstruction is a rare complication which occurs relatively early after implantation. We present the transesophageal echocardiographic findings in a case of cuspal thrombosis of a Hancock aortic prosthesis which required valve replacement.     

Tissue-type plasminogen activator (t-PA) lysis of aortic and mitral valve thrombosis

Valve thrombosis is one of the most serious complications after prosthetic valve replacement. We report the use of tissue-type plasminogen activator (t-PA) in the treatment of a patient with thrombosed aortic and mitral valves. Thrombolysis resulted in immediate hemodynamic improvement and resolution of congestive heart failure, thereby avoiding surgical intervention. Based on our experience, thrombolysis with t-PA is an effective alternative in the treatment of thrombosed prosthetic valves.     

Postoperative color flow duplex scanning in aortic endografting

PURPOSE: To report the feasibility and sensitivity of duplex sonography compared to computed tomography (CT) for aortic endograft follow-up surveillance. METHODS: In a 26-month period, 113 aortic aneurysm patients received 79 tube and 34 bifurcated stent-grafts. Follow-up used contrast-enhanced CT scanning and duplex sonography with an intravenous ultrasound contrast agent (Levovist). RESULTS: Eleven patients (9.7%) were converted to open repair; 1 died from hemorrhagic shock secondary to retroperitoneal hematoma. The mean follow-up time was 7.2 months (range 1 to 24), during which 5 patients died of unrelated causes. Sixteen primary (within 30 days) and 5 secondary endoleaks were detected by duplex after tube graft implantation. Among 5 endoleaks due to retrograde side-branch perfusion, 3 were detected only with contrast-enhanced duplex scanning. Iliac artery occlusion was also documented using duplex; however, 2 stent fractures could not be seen with ultrasound. Ten primary endoleaks were detected in bifurcated stent-graft patients. One endoleak originating from the distal iliac limb anchoring site was missed by duplex owing to bowel gas. Graft limb thrombosis was clearly identified by lack of a flow signal on duplex. CONCLUSIONS: Duplex sonography could be a valuable, reliable, and economical surveillance tool for endovascular aortic reconstructions. The adjunctive use of an intravenous ultrasound contrast agent increased the sensitivity for detecting endoleak to a level comparable to contrast-enhanced CT scanning. However, stent fractures may not be seen on ultrasound, and bowel gas can interfere with obtaining an adequate image.     

Development of a mouse aortic transplant model of chronic rejection

Chronic rejection is the most common cause of late graft failure after solid organ transplantation. A model of chronic rejection, the rat aortic allograft, has histologic features that parallel those in the vessels of human transplanted organs. However, the molecular tools required to dissect the immunology of chronic rejection are unavailable in the rat. We developed aortic transplantation in the mouse as a new model of chronic rejection. This will allow the use of the diversity of recombinant cytokines and monoclonal antibodies available for the mouse and its well-defined genetics to investigate chronic rejection in greater detail. We describe the perioperative care and surgical technique for the model in which a 1 cm segment of donor thoracic aorta was used to replace a section of recipient abdominal aorta below the renal arteries and above the aortic bifurcation. Mortality rates were initially high (70%) due to thrombosis and shock. Changes in technique and operator facility resulted in a high rate of success (75%). After 192 operations, the current success rate is > 80%. Mice free from complications at 12 hrs postop had indefinite survival, and after 2 months the typical vascular lesion of chronic rejection was present. This new model of chronic rejection will be a valuable tool to study the molecular immunology and genetics of chronic rejection.     

Three-year experience with the White-Yu Endovascular GAD Graft for transluminal repair of aortic and iliac aneurysms

PURPOSE: To report a > 3-year experience with a modular, balloon-expandable endovascular graft used for aneurysm exclusion in the aorta and other arteries. METHODS: The customized White-Yu Endovascular GAD Graft, a woven polyester prosthesis with an intrinsic Elgiloy wire graft attachment system along the body of the graft, is a flexible endograft design available in straight, tapered, and bifurcated versions that can be delivered transluminally through 18F to 24F sheaths. RESULTS: Since July 1993, 93 patients have received the White-Yu endograft for treatment of 76 abdominal aortic, 3 thoracic aortic, 13 iliac, and 1 popliteal aneurysms. Of the 79 aortic procedures, 39 involved straight tube grafts, 20 were tapered aortoiliac models, and 20 were bifurcated devices. Success rates for tube grafts were 81% in the abdominal aorta and 100% for the thoracic aorta; 5 primary endoleaks (14%) and 2 conversions to surgery (5.6%) occurred with this graft type. Aortoiliac grafts were deployed successfully in 95% (19/20) of cases with 1 conversion (5%) due to thrombosis. Seventy-five percent of the bifurcated endograft procedures were successful, with 4 conversions (20%) for technical failures and 1 graft thrombosis. Four additional endografts were deployed to treat two primary and two secondary endoleaks in tube graft patients. Two access-related arterial injuries were treated surgically. There was one case of embolus to the distal femoral artery but no microembolization. Overall perioperative (30-day) mortality was 3.1%. Over a mean 18-month follow-up (range 2 to 39), no late graft thrombosis, stenosis, or graft migration has been seen on CT scans or X ray. Endoleak has not been detected in any aortoiliac or bifurcated graft. Aneurysm size has diminished consistently in successfully treated cases. CONCLUSIONS: The White-Yu endograft appears to offer a safe, efficacious, and minimally invasive means of excluding aneurysms from the circulation. Improvements in patient selection, surgical techniques, and equipment have reduced the incidence of endoleak and conversion to open repair over the course of the evaluation.     

Mid-diastolic aortic valve opening in bacterial endocarditis of aortic valve

Echocardiographic features of acute aortic regurgitation resulting from bacterial endocarditis have been well documented (Nathan et al., 1980; Weaver et al., 1977; Wray, 1975a), and include thick shaggy echoes from aortic valve in diastole, fine diastolic flutter of aortic valves suggestive of rupture of cusps, and premature closure of mitral valves. Echocardiography being a sensitive noninvasive technique for detecting aortic valve vegetations is heavily relied on for earlier diagnosis and prompt therapy of these patients. Prognosis of echocardiographically positive endocarditis is known to be worse than for echo-negative patients. The following case is being presented because of an unusual echocardiographic manifestation with mid-diastolic aortic valve opening secondary to flail aortic valve from staphylococcal endocarditis of the aortic valve.     

Redo aortic grafting after treatment of aortic graft infection

PURPOSE: This study was performed to determine the indications, operative strategy, and hemodynamic benefit of redo aortic grafting procedures after earlier excision of an infected aortic graft. METHODS: Among 164 patients treated for aortic graft infection, 15 later underwent redo aortic grafting procedures an average of 18 months (range, 1 to 59 months) after removal of an infected aortic graft. Redo grafting procedures were performed for leg ischemia (n = 11) or infection (proven, n = 3; suspected, n = 1). The new aortic graft originated either from the distal thoracic aorta (n = 5) or from the juxtarenal aortic stump (n = 10). Follow-up averaged 56 months (range, 7 to 110 months). RESULTS: All patients survived the redo grafting procedure. In the eleven patients who had ischemic symptoms, redo grafting procedures uniformly resulted in symptomatic improvement with an increase in ankle-brachial indexes (0.78 +/- 0.34 vs 0.50 +/- 0.29; p = 0.02). A graft limb occlusion developed in two of these patients (3 and 6 months), but no limbs were amputated. In the four patients who had proven or suspected extraanatomic bypass graft infection, there was one graft limb occlusion (29 months) and one amputation (17 months). Overall, recurrent graft infection occurred in three of 15 patients and may be more frequent in patients who have a proven extraanatomic bypass graft infection (2 of 3 vs 1 of 12; p = 0.08). Infection accounted for two of the three graft limb occlusions and two of the three late deaths. Recurrent infection was not associated with early (< 1 year) regrafting procedures, and culture results did not correlate with the microbiologic features of the primary infection. CONCLUSIONS: Redo aortic grafting procedures can be performed safely and at relatively early intervals (6 to 12 months) after removal of the infected aortic graft. The procedure reliably relieves ischemic symptoms of the hemodynamically inadequate extraanatomic bypass graft. Reinfection remains a risk after redo aortic grafting procedures, particularly when treating established extraanatomic bypass graft infection.     

Rupture of an abdominal aortic aneurysm following acute descending thoracic aortic dissection. Case report

The coexistence of an abdominal aortic aneurysm and an acute aortic dissection seems to be rare and only a few reports are to be found in the literature. We report a case of a patient with acute aortic dissection of the descending thoracic aorta that caused rupture of a pre-existing abdominal aortic aneurysm. The literature is also thoroughly reviewed.     

Treatment of the aortic valve and ascending aorta. The significance of reconstructive methods on the aortic root

BACKGROUND AND OBJECTIVE: The standard surgical repair of disease of the aortic valve and the ascending aorta has been combined replacement, which includes the disadvantage of inserting a mechanical valve. We have investigated an individualized approach which preserves the native valve. PATIENTS AND METHODS: Between October 1995 and October 1997, a consecutive total of 101 patients (72 men, 29 women, aged 21-83 years) underwent operations for disease of the ascending aorta: aortic dissection type A in 34 patients, aneurysmal dilatation in 67. Dilatation of the aortic arch was associated with aortic regurgitation in 58 patients. There were 11 patients with aortic valve stenosis or previously implanted aortic valve prosthesis among a total of 46 whose aortic valve was replaced (group II). Supracommissural aortic replacement with a Dacron tube was performed in 16 patients (group I) with normal valve cusps and an aortic root diameter < 3.5 cm. In 28 patients with an aortic root diameter of 3.5-5.0 cm the aortic root was remodelled (group III). Resuspension of the native aortic valve was undertaken in 11 patients with aortic root dilatation of > 5.0 cm (group IV). RESULTS: Operative intervention was electively performed in 72 patients, without any death. Of 29 patients operated as an emergency for acute type A dissection four died (14%). In 55 of the 58 patients with aortic regurgitation in proved possible to preserve native aortic valve (95%). In the early postoperative phase and after an average follow-up time of 11.8 months, transthoracic echocardiography demonstrated good aortic valve function, except in one patient each of groups III and IV who developed aortic regurgitation grades I or II. CONCLUSION: The described individualized approach makes it possible to preserve the native aortic valve in most patients with aortic regurgitation, at a low risk. Follow-up observations so far indicate good results of the reconstruction.     

Open distal anastomosis or aortic balloon occlusion technique during complete aortic arch replacement

The technique of open distal anastomosis or application of aortic balloon occlusion catheter designed to occlude the descending thoracic aorta have been used in 33 and 19 patients, respectively, to control bleeding during the procedure of distal anastomosis for complete aortic arch replacement with a prosthetic graft. These two techniques allowed us a simple approach to the lesion and the avoidance of clamp injury to the fragile aortic tissue. Open distal anastomosis was applied for 91% patients of operated aortic dissection and all emergent cases, it's duration ranged from 10 to 110 minutes with an average of 58 minutes under 18.2 degrees C of lowest esophageal temperature. On the other hand, aortic occlusion balloon was inserted for mainly true aortic aneurysm patients without an emergency, and helped to maintain the perfusion pressure on a lower part of body around 50 mmHg by the 1550 ml/min in an average of perfusion flow femoral artery under 21.2 degrees C of temperature. The difference of postoperative renal and liver function evaluated by serum enzyme levels of total bilirubin, GOT, GPT, LDH, creatinine and BUN did not reach to statistical significance between the patients using open distal anastomosis and balloon occlusion, however, the incidence of postoperative complication including either renal, liver dysfunction, abdominal problem or paraplegia was significantly higher in the patient group with open distal technique. Either open distal anastomosis or aortic balloon occlusion technique would be appropriately selected according to the patient's characteristics or the condition of aortic disease to be operated.     

Fate of the excluded abdominal aortic aneurysm sac: long-term follow-up of 831 patients

PURPOSE: Nonresective treatment of the infrarenal abdominal aortic aneurysm by proximal and distal ligation of the aneurysm sac (exclusion) combined with aortic bypass has been previously reported. A 10-year experience with 831 patients undergoing this procedure was reviewed. METHODS: From 1984 to 1994, 831 (761 elective, 70 urgent) of 1103 patients being treated for abdominal aortic aneurysm underwent repair with the retroperitoneal exclusion technique. Perioperative morbidity and mortality, estimated blood loss, transfusion requirements, natural history of the excluded aneurysm sac, and long-term survival were all assessed. RESULTS: The operative mortality rate for patients undergoing exclusion and bypass was 3.4%. The incidence of nonfatal perioperative complications was 5.2%. Colon ischemia requiring resection occurred in 2 (0.2%) of the 831 patients. Estimated blood loss was 638 +/- 557 cc (50 to 330 cc). On follow-up 17 (2%) patients were found to have patent aneurysm sacs as detected by duplex examination. Fourteen patients required surgical intervention. No cases of graft infection or aortoenteric fistula have been noted. CONCLUSION: Retroperitoneal exclusion and bypass is a viable alternative to traditional open endoaneurysmorraphy in surgery for abdominal aortic aneurysm. Most excluded aneurysm sacs have thrombosis without any long- or short-term complications; however, in a small number of patients delayed rupture of patent aneurysm occurs, thus emphasizing the need for diligent follow-up and appropriate intervention.     

Repair of the aortic arch with fibrin glue in type A aortic dissection

Location of the intimal tear in the aortic arch in type A aortic dissection is for many authors an indication for replacement of the aortic arch, but this operation has a high in-hospital mortality rate: 20% to 40%. Instead, we suggest repairing the aortic arch by injecting fibrin glue, which contains a human sealer protein concentrate, between the two dissected layers under circulatory arrest while replacing the ascending aorta. To evaluate this technique, we reviewed 45 successive patients operated on for type A acute aortic dissection between January 1989 and July 1993, of which 6 had the intimal tear located on or extending into the aortic arch. Mean age was 71 +/- 4.2 years (range 68 to 74). After proximal supracoronary anastomosis with a collagen-impregnated graft, aortic arch repair was achieved by injecting fibrin glue between the two layers, using circulatory arrest at a mean temperature of 22 degrees C, with a mean duration of 24 minutes. This obliterated the dissection in the arch and also the intimal flap. The distal part of the graft was then anastomosed to the proximal portion of the aortic arch at the origin of the innominate artery under circulatory arrest. There were no early or late deaths. All patients were asymptomatic at a mean follow-up of 2.6 years. Follow-up angioscan showed obliteration of the dissection in the aortic arch in all patients; there were two patients with dilatation of the distal aortic arch of 40 and 45 mm.(ABSTRACT TRUNCATED AT 250 WORDS)     

Congenital quadricuspid aortic valves

BACKGROUND: Quadricuspid aortic valve is an uncommon congenital anomaly. We report a case in a patient hospitalized for heart failure. CASE REPORT: A 62-year old patient with exercise-induced dyspnea was hospitalized for heart failure. Heart auscultation revealed a diastolic aortic murmur attributed to a quadricuspid aortic valve evidenced at echocardiography. DISCUSSION: Quadricuspid aortic valves usually have three cusps of equivalent size and a small fourth cusp between the right coronary cusp and the non-coronary cusp. Aortic regurgitation is usually observed requiring valve replacement in 50% of the cases. The anomaly may be associated with other congenital anomalies of the coronary arteries warranting systematic coronarography prior to valve replacement.     

Intraoperative heparinisation, blood loss and myocardial infarction during aortic aneurysm surgery: a Joint Vascular Research Group study

OBJECTIVES: The primary aim of this prospective multi-centre study involving patients undergoing elective abdominal aortic aneurysm (AAA) surgery was to investigate the relationship between intraoperative intravenous heparinisation, blood loss during surgery and thrombotic complications. METHODS: Two hundred and eighty-four patients were randomised to receive intravenous heparin (n = 145) or no heparin (n = 139). Groups were evenly matched for age, sex, weight, aneurysm size, haemoglobin concentration, platelet counts and distal occlusive disease measured by ankle/brachial systolic pressure. RESULTS: There were no statistically significant differences in blood loss (median 1400 ml vs. 1500 ml; z = 0.02, p = 0.98, 95% C.I. = -200 to 200), blood transfused (4.0 units vs. 4.0 units; z = 1.09, p = 0.28, 95% C.I. = -1 to 0) or distal thrombosis between the two groups. However, analysis of the clinical outcome revealed that 5.7% of the non-heparin group but only 1.4% of the heparinised patients suffered a fatal perioperative myocardial infarction (MI); p < 0.05. All MI, including non fatal events, affected 8.5% and 2% respectively (p = 0.02). CONCLUSIONS: Heparin does not increase blood loss or the need for blood transfusion during surgery. Heparin is not necessary to prevent distal thrombosis when the aorta is cross clamped. The results of the study are consistent with the known mechanisms leading to intraoperative MI and strategies for its prevention. Intravenous heparin, given before aortic cross clamping, is an important prophylaxic against perioperative MI in relation to AAA surgery.     

Combined tracheal resection and aortic valve replacement with a cryopreserved aortic valve allograft

A 69-year-old patient presented with an association of tracheal squamous cell carcinoma and severe aortic valve stenosis. As there was no evidence of metastatic spread a potentially curative resection could be considered. The patient underwent tracheal resection and aortic valve replacement in a one-stage procedure. In light of the potential risk of infection to a prosthetic valve, a cryopreserved aortic valve homograft was implanted. The patient made a full recovery and is doing well after 2 years of follow-up.     

Upper T mini-sternotomy for aortic valve operations

OBJECTIVES: New minimally invasive approaches for cardiac surgical procedures are constantly being developed in the hope of decreasing patient morbidity and enhancing the postoperative recovery. This report reviews the use of an upper T mini-sternotomy approach to aortic valve surgery. PATIENTS: Nine consecutive nonselected patients (5 men, 4 women, mean age, 66 years) underwent isolated aortic valve replacement with the use of this approach. Two patients had isolated aortic valve stenosis, three had isolated aortic valve incompetence, and four patients had mixed aortic valve disease. RESULTS: In all cases, an excellent view of the aortic valve was obtained, aortic valve replacement with a bileaflet mechanical prostheses was performed, and no intraoperative difficulties were encountered. Mean aortic cross-clamp time was 83 min and mean cardiopulmonary bypass perfusion time was 97 min. All patients were extubated in the operating room at the end of the surgical procedure, and there were no postoperative complications. All patients were discharged home on postoperative day 3, and there were no late complications. CONCLUSION: Through an upper T mini-sternotomy, aortic valve surgery can be performed in the conventional manner using standard surgical instruments with no alteration in cardiopulmonary bypass and myocardial protection routines. With this method, postoperative pain is reduced and patient recovery is expeditious.     

Aortic arch thrombosis in the neonate

Two cases of neonatal aortic arch thrombosis are reported. One patient, who had ascending aortic thrombosis, died preoperatively. The other had reoperation and is alive and well at 6 months' follow-up. No obvious cause was found.