Valve surgery combined with coronary artery operation: is the use of internal mammary artery a predictor for early complications?

The internal mammary artery (IMA) provides better early and long-term patency than venous grafts do. Although IMA is the conduit of choice in isolated coronary artery bypass grafting (CABG), its use in combined procedures is not routine in some cardiovascular units. During a 16-month period, 188 patients underwent valve surgery combined with CABG. Internal mammary grafts were used in 68/188 (36%) patients (group 1) and vein grafts without arterial grafts (group 2) in 120/188 (64%). Left IMA was implanted in 67/68 (99%) and right IMA in 1/68 1%) cases. Surgeon A used IMA in 28/44 (64%), surgeon B in 20/32 (63%), surgeon C in 18/44 (41%), surgeon D in 1/4 (25%) and surgeon E in 1/63 (2%) patients. The final decision to use IMA in a combined procedure was left up to the surgeon. Statistically, the preoperative- and perioperative data were identical in the two groups, although the frequency of IMA grafting in patients with double valve replacement and reoperation was lower (1/68 vs 11/120, ns, and 3/68 vs 9/120, ns). Ten of 188 (5.3%) patients died within 30 days after operation. Longer cross-clamp time (P = 0.008) and mitral valve replacement (P = 0.05) were independent risk factors for early death. The use of IMA did not increase the risk of early mortality. The postoperative variables were similar in the IMA and vein groups, in particular data suggesting perioperative myocardial infarction (CK-MB, catecholamine support). Postoperative mechanical ventilation was longer in the IMA group, although not significantly (P = 0.06). Early mortality and morbidity were identical in the two groups in combined procedures. We did not find any hints for an increased risk of using IMA in this type of surgery. Internal mammary artery implantation is safe in selected patients undergoing combined valve and CABG surgery. Beside the better long-term patency of IMA, its use may have several technical advantages.

Coronary arteriovenous fistula: surgical correction of a rare form.

In a 60-year-old woman with long-standing angina left heart catheterisation revealed peripheral and central coronary arteriovenous fistulae connected to the left and right coronary system and opening into the pulmonary artery. The fistulae connected to terminal coronary artery branches were corrected by ligation of these feeding arteries while the electrocardiogram was continuously monitored. The central fistulae were closed via a transcoronary approach of the left anterior descending artery. Knowledge of different surgical techniques helps to prevent perioperative myocardial infarction and late fistula recurrence.

The diagnosis of thoracic aortic dissection by noninvasive imaging procedures.

BACKGROUND AND METHODS: This study was designed to assess the safety and reliability of new noninvasive imaging methods as compared with aortography in the diagnosis of dissection of the thoracic aorta. One hundred ten patients with clinically suspected aortic dissection followed a diagnostic protocol that included transthoracic and transesophageal color-flow Doppler echocardiography (TTE and TEE), contrast-enhanced x-ray computed tomography (CT), and magnetic resonance imaging (MRI). Imaging results were compared in a blinded fashion and validated independently against intraoperative findings in 62 patients, autopsy findings in 7, and the results of contrast angiography in 64. RESULTS: The sensitivities of MRI, TEE and x-ray CT for detecting dissection were similar, at 98.3, 97.7, and 98.3 percent, respectively; TTE had a sensitivity of only 59.3 percent (P < 0.005). The specificities of both TTE (83.0 percent) and TEE (76.9 percent) were lower than those of x-ray CT (87.1 percent) and MRI (97.8 percent; P < 0.05), mainly as a result of false positive findings in the ascending aorta. MRI and x-ray CT were more sensitive than TTE in detecting the formation of thrombus in the entire thoracic aorta (P < 0.05), but were not superior to TEE in this regard. CT was not effective in detecting an entry site or aortic regurgitation, but MRI and TEE accurately identified both. Two patients died during or soon after CT and TEE, and three died between retrograde angiography and surgery. CONCLUSIONS: A noninvasive diagnostic strategy using MRI in all hemodynamically stable patients and TEE in patients who are too unstable to be moved should be considered the optimal approach to detecting dissection of the thoracic aorta. Comprehensive and detailed evaluation can thus be reduced to a single noninvasive diagnostic test in the investigation of suspected dissection of the thoracic aorta.

[Detection of dissection of the thoracic aorta: improved specificity by magnetic resonance tomography in comparison with echocardiography techniques]. / Nachweis der thorakalen Aortendissektion: Verbesserte Spezifität durch Magnetresonanztomographie gegenüber echokardiographischen Techniken.

The purpose of this study was to assess the reliability of conventional transthoracic and transoesophageal two-dimensional echocardiography combined with color-coded Doppler flow imaging (TEE) and ECG-triggered magnetic resonance imaging (MRI) for the diagnosis of thoracic aortic dissection and associated epiphenomena. A total of 53 patients with clinically suspected aortic dissection were subjected to a transthoracic and transoesophageal ultrasound examination and magnetic resonance imaging; the results of each imaging modality were compared and validated against the morphological standards of contrast angiography (n = 53) and/or intraoperative findings (n = 27) or autopsy (n = 7). In this series no deleterious events were encountered with either non-invasive imaging method. In contrast to conventional echocardiography the sensitivities of both MRI and TEE were 100% for detecting a dissection of the thoracic aorta, irrespective of its location. However, the specificity of TEE was lower than the specificity of MRI for a dissection (TEE 68.2% versus MRI 100%; p less than 0.005), which resulted from false positive TEE findings mainly confined to the ascending segment of the aorta (specificity of TEE 78.8% versus 100% by MRI; p less than 0.01). In addition, MRI proved to be more sensitive than TEE in detecting the formation of thrombus in the false lumen of both the aortic arch (p less than 0.01) and the descending segment of the aorta (p less than 0.05). There were no discrepancies between the two imaging techniques in detecting the site of entry to a dissection, aortic regurgitation or pericardial effusion. Both MRI and TEE are atraumatic, safe, and highly sensitive methods to identify and classify acute and subacute dissections of the entire thoracic aorta. However, TEE is associated with lower specificity for lesions in the ascending aorta. These results may still favor TEE after a precursory screening transthoracic echogram in suspected aortic dissection, but will establish MRI as an excellent method to avoid false positive findings. Anatomical mapping by MRI may emerge as a promising comprehensive approach and, eventually, as a morphological standard to guide surgical interventions.

Diagnosis of thoracic aortic dissection. Magnetic resonance imaging versus transesophageal echocardiography.

BACKGROUND: Aortic dissection requires prompt and reliable diagnosis to reduce the high mortality. The purpose of this study was to assess the reliability of both ECG-triggered magnetic resonance imaging (MRI) and transesophageal two-dimensional echocardiography combined with color-coded Doppler flow imaging (TEE) for the diagnosis of thoracic aortic dissection and associated epiphenomena. METHODS AND RESULTS: Fifty-three consecutive patients with clinically suspected aortic dissection were subjected to a dual noninvasive imaging protocol in random order; imaging results were compared and validated against the independent morphological "gold standard" of intraoperative findings (n = 27), necropsy (n = 7), and/or contrast angiography (n = 53). No serious side effects were encountered with either imaging method. In contrast to a precursory screening transthoracic echogram, the sensitivities of both MRI and TEE were 100% for detecting a dissection of the thoracic aorta irrespective of its location. The specificity of TEE, however, was lower than the specificity of MRI for a dissection (TEE, 68.2% versus MRI, 100%; p less than 0.005), which resulted mainly from false-positive TEE findings confined to the ascending segment of the aorta (TEE, 78.8% versus MRI, 100%; p less than 0.01). In addition, MRI proved to be more sensitive than TEE in detecting the formation of thrombus in the false lumen of both the aortic arch (p less than 0.01) and the descending segment of the aorta (p less than 0.05). There were no discrepancies between the two imaging techniques in detecting the site of entry to a dissection, aortic regurgitation, or pericardial effusion. CONCLUSIONS: Both MRI and TEE are atraumatic, safe, and highly sensitive methods to identify and classify acute and subacute dissections of the entire thoracic aorta. TEE, however, is associated with lower specificity for lesions in the ascending aorta. These results may still favor TEE as a semi-invasive diagnostic procedure after a precursory screening transthoracic echogram in suspected aortic dissection, but they establish MRI as an excellent method to avoid false-positive findings. Anatomic mapping by MRI may emerge as the most comprehensive approach and morphological standard to guide surgical interventions.

[Dissecting aneurysm of the thoracic aorta. Diagnosis--surgical management--results]. / Das Aneurysma dissecans der thorakalen Aorta. Diagnose--operatives Management--Ergebnisse.

From 1980 to 1989, 84 patients underwent surgery for dissection of thoracic aortic aneurysms. According to the DeBakey classification there were 23 dissections of type I, 35 of type II and 26 of type III. Magnetic resonance imaging and combined transesophageal and transthoracic echocardiography are highly sensitive and specific methods for diagnosis and followup of aortic dissection. 10% of the patients had to undergo surgery again during the first 5 years. The 5-year-survival rate was 56.1% and the 10-year rate was 40.1%.

[Suppression of the cell-mediated immunity in minor histoincompatible rat kidney allograft recipients (author's transl)]. / Suppression der zellgebundenen Immunität bei schwach histoinkompatiblen Rattennierenallotransplantatempfängern.

To study the immunological status of recipients of major compatible and minor incompatible kidney allografts, we transplanted FiS and FLF1 kidneys into LEW rats. Most of the FiS kidneys were rejected within 55 days. Of 24 recipients, only 4 survived longer than 4 months. However, two-thirds of the FLF1 recipients survived longer than 4 months. The other third died with 64 days. During the first postoperation week a high level of lymphocytotoxin was detected in the serum of the FiS kidney recipients. Thereafter hardly any alternation of its titer was found, and no variation among the recipients of major histocompatible kidney allografts was shown. The FLF1 kidney recipients showed a low titer of antibody. The hemagglutinin titer showed the same trend as the lymphocytotoxin titer. A blocking serum factor could not be found in the serum of the kidney recipients with the microcytotoxity assay method or with the allorosette-formation inhibition test. Cellular immunity, which was studied with the GvH-reaction and microcytotoxity assay, was detected in the first postoperative week. However, this immunity was gradually supressed, and after 6 weeks was no longer to be found. This immunological status remained unchanged in the indefinitive surviving kidney-recipients in spite of antigen inoculation with two skin allografts of donor origin. This immunological status could be defined as "graft acceptance".