Nobuyoshi Kawaharada

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.

Three or more median sternotomies for patients with valve disease: role of computed tomography

BACKGROUND We evaluated the effects of computed tomographic (CT) scan-guided third or fourth median sternotomies for valve operations on the incidence of resternotomy-related complications and early mortality. METHODS Ninety patients undergoing valve replacement with third or fourth time sternotomy were divided into two groups. One group (CT group) consisted of 64 patients who had undergone routine CT scans preoperatively after 1991 to assess the possibility of sternotomy-related bleeding, and the other group (no CT group) comprised the remaining 26 patients who did not receive CT scans. RESULTS Hospital death occurred in 4 patients (6%) in the CT group and in 6 patients (23%) in the no CT group (p = 0.0309). Multivariate analysis indicated NYHA class 4 (odds ratio [OR] = 6.99) and year of operation (OR = 1.05) to be predictors of hospital death. Preoperative CT scans revealed that 8 patients were considered to be high risk for resternotomy, they underwent femorofemoral bypass before sternal division was performed. Hemorrhage occurred upon sternal reentry in 2 of these 8 patients. The incidences of sternotomy-related injury were 19% (5/26) in the no CT group and only 3% (2/64) in the CT group (p = 0.0198). Multivariate analyses demonstrated a fourth sternotomy (OR = 4.31) to be a predictor of resternotomy-related injury. CONCLUSIONS CT scans provide preoperative information on retrosternal adhesions. When a distended heart or expanded aorta has adhered to the sternum, femorofemoral cannulation should be performed before sternotomy. Third and fourth sternotomies, though demanding procedures, can be performed safely using the described strategy.

Hybrid treatment for aortic arch and proximal descending thoracic aneurysm: experience with stent grafting for second-stage elephant trunk repair

BACKGROUND Aortic aneurysm affecting the arch and proximal descending thoracic aorta may require a two-stage repair, which includes proximal elephant trunk graft placement and completion of descending thoracic aortic repair. The combination of open surgery and endovascular grafting may improve the morbidity and mortality of the patient population at risk. METHODS Between February 2001 and March 2007, 258 patients underwent thoracic aortic endovascular grafting at our institution, wherein 31 patients underwent a hybrid approach involving proximal arch repair and elephant trunk graft replacement, and endovascular completion procedures. All patients, who underwent combined endovascular and open procedures in the management of the aortic arch and proximal descending thoracic aortic aneurysms, were reviewed and analysed retrospectively. RESULTS The interval between the first and second stage ranged from 0 to 14 months with a mean interval of 3.1 months. Follow-up ranged from 0 to 70 months with a mean of 31 months. Technical success was achieved in all patients. The 1, 12, 36 and 60-month mortality rates were 6.4%, 16.5%, 26.7% and 26.7%, respectively. Caudal migration of the endograft occurred in three patients, who underwent conversion to open surgery. Two cases of paraparesis but no paraplegias or strokes were recorded. CONCLUSIONS Staged procedures using endovascular grafting in the treatment of the arch and proximal descending thoracic aneurysm may have the potential to reduce morbidity and mortality rates. Although long-term results are still pending, this early experience demonstrates the safety and early-term effectiveness of this hybrid approach, which consists both of endovascular and open surgical procedures.

Anatomical Study of Blood Supply to the Spinal Cord

BACKGROUND Low incidences of spinal cord ischemia after thoracoabdominal aortic aneurysm repair, despite sacrifice of all segmental arteries, have recently been reported. This, however, cannot be explained by previous anatomical findings, which prompted us to perform an anatomical study of blood supply to the spinal cord. METHODS Fifty-five spinal cords from Japanese formol-fixed cadavers (mean age, 79 +/- 10 years) were studied. Diameters of the anterior spinal artery (ASA) above and below the junction with the arteria radicularis magna (ARM) and diameters of the ARM were measured using the NIH image program (National Institutes of Health Image 1.58). RESULTS The degree of narrowing of the ASA, defined as the diameter above the ARM expressed as a percentage of the diameter below the ARM, ranged from 23% to 161% and averaged 66% +/- 30%. The degree of narrowing was plotted against the ARM diameter divided by the ASA diameter above the junction to examine the impact of the degree of narrowing on distal spinal blood flow from the ARM. The degree of narrowing was related to distal spinal blood flow from the ARM (r= 0.56, p < 0.0001). CONCLUSIONS The degree of narrowing of the ASA varies considerably. Furthermore, distal spinal blood supply becomes progressively dependent on the ARM as the narrow point of the ASA becomes narrower. These anatomical findings of spinal blood supply should be useful for elucidating the mechanisms of spinal cord injury after repair of extensive thoracoabdominal aneurysms.

Postoperative Acute Exacerbation of IPF after Lung Resection for Primary Lung Cancer

Idiopathic pulmonary fibrosis (IPF) is characterized by slowly progressive respiratory dysfunction. Nevertheless, some IPF patients experience acute exacerbations generally characterized by suddenly worsening and fatal respiratory failure with new lung opacities and pathological lesions of diffuse alveolar damage. Acute exacerbation of idiopathic pulmonary fibrosis (AEIPF) is a fatal disorder defined by rapid deterioration of IPF. The condition sometimes occurs in patients who underwent lung resection for primary lung cancer in the acute and subacute postoperative phases. The exact etiology and pathogenesis remain unknown, but the condition is characterized by diffuse alveolar damage superimposed on a background of IPF that probably occurs as a result of a massive lung injury due to some unknown factors. This systematic review shows that the outcome, however, is poor, with postoperative mortality ranging from 33.3% to 100%. In this paper, the etiology, risk factors, pathogenesis, therapy, prognosis, and predictors of postoperative AEIPF are described.

Surgical treatment for primary lung cancer combined with idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is defined as a specific form of chronic, progressive fibrosing interstitial pneumonia of unknown cause. IPF is associated with an increased risk of lung cancer, and lung cancer patients with IPF undergoing pulmonary resection for non-small cell lung cancer have increased postoperative morbidity and mortality. Especially, postoperative acute exacerbation of IPF (AEIPF) causes fatal status and long-term outcomes are worse than for patients without IPF, although certain subgroups have a good long-term outcome. A comprehensive review of the current literature pertaining to AEIPF and the late phase outcome after the context of a surgical intervention was performed.

Contralateral Lung Injury Associated With Single-Lung Ischemia-Reperfusion Injury

BACKGROUND There have been very few studies on the effect of single-lung ischemia-reperfusion on the function of the contralateral lung. This study was designed to clarify the effect. METHODS Fifteen mongrel dogs were divided into two groups. In group 1 (n = 7), the left lung was subjected to ischemia without ventilation for 90 minutes, and then reperfused. In group II (n = 8), the lung was not subjected to ischemia, and was ventilated during the 90-minute ischemia of group I. Arterial blood gas, hemodynamics, extravascular lung water, and airway pressure were measured. Pulmonary biopsy was performed to evaluate adenine nucleotide levels. The protein concentration and phosphorous concentration of phospholipids in bronchoalveolar lavage fluid were measured. RESULTS Group I, with perfusion and ventilation of the right lung alone, was significantly inferior to group II with respect to arterial blood gas, right pulmonary compliance, extravascular lung water of the right lung, and the protein concentration in the bronchoalveolar lavage fluid of the right lung after the 90-minute period. CONCLUSIONS These results indicate that 90 minutes of warm ischemia and reperfusion of the left lung caused deterioration of not only the left but also contralateral right pulmonary function.

An experimental evaluation of the lactate concentration following mesenteric ischemia.

PurposeAlthough a diagnosis of mesenteric necrosis can easily be made, mesenteric ischemia is sometimes overlooked, especially in the acute phase. We experimentally evaluated the time course of the lactate concentration, which may be a possibly useful variable in making a diagnosis of mesenteric ischemia, and determined how an early diagnosis can be made.MethodsThe superior mesenteric artery (SMA) was surgically ligated in an anesthetized pig. Blood tests, including a blood gas analysis, were done using samples from the superior mesenteric vein (SMV), hepatic vein, femoral vein, and artery until 6 h after SMA ligation.ResultsThere were no variables in any samples that showed a significant change within 4 h after SMA ligation except for samples taken from the SMV. All acidosis-related variables had changed significantly within 6 h after ischemia. Among them, the lactate concentration only in the SMV was observed to have increased significantly within one hour after SMA ligation.ConclusionsCurrently available peripheral blood tests, including tests using blood obtained from the hepatic vein, do not enable the detection of mesenteric ischemia within 4 h after onset. In a case in which an exploratory laparotomy is performed, the measurement of the lactate concentration in SMV is thus considered to be a useful supplementary test for making a prompt diagnosis of mesenteric ischemia in an early phase.

Examination of intercostal arteries with transthoracic Doppler sonography.

Objective: There has been no study on the measurement of blood flow of the intercostal artery (ICA) or lumbar artery (LA) with the use of transthoracic Doppler sonography. Here, the method of the ICA depiction and flow measurement were described, and we suggested the clinical usage of this method. Methods: Twelve healthy subjects were examined. The performance of transthoracic Doppler sonography was approached from the back on lateral decubitus position. The intercostal artery was depicted by two‐dimension mode with color flow, and the inner diameter was measured. Peak systolic velocity (PSV), end‐diastolic velocity (EDV), velocity‐time integral (VTI), and heart rate (HR) were measured with pulsed Doppler, and the blood flow was calculated. Results: Bilateral ICAs and LAs from Th4 to L4 were measurable with this method. The PSV of Lt Th9 was the fastest at 43.3 ± 10.1 cm/sec and the PSV of the ICAs gradually decreased as distance from Th9 increased. As for the flow volume, the left Th11 was the greatest at 99.7 mL/min, and the flow volume of the ICA gradually decreased as distance from Th11 increased. The velocity and blood flow of right ICA tended to be lower than the left in the same spinal level. Conclusions: Evaluation technique of serial ICAs and LAs was shown. We think that it may be a clinically useful method in the study of spinal cord circulation in the repair of cases of descending thoracic or thoracoabdominal aortic aneurysm. (Echocardiography 2010;27:17‐20)

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.