The Significance of Screening for HLA Antibodies in the Long-Term Follow-up of Pediatric Liver Transplant Recipients

BACKGROUND

Post-transplant donor-specific anti-HLA antibodies (DSA) reportedly have detrimental effects on the outcomes of organ transplantation. However, the prevalence of post-transplant DSA in the long term after pediatric liver transplantation remains unclear, and the significance of post-transplant DSA is unknown. The aim of this cross-sectional study was to determine the prevalence of and characteristics of patients with post-transplant DSA.

MATERIALS AND METHODS

Of the 84 pediatric liver transplant recipients who were followed up in the outpatient department of our institution, 34 patients with available HLA typing data were included after they or their parent(s) provided informed consent for DSA evaluations. Luminex single-antigen bead assays were performed, and a mean fluorescence intensity of ≥1000 was used as the cut-off for a positive reaction.

RESULTS

No class I DSA were detected, whereas class II DSA were detected in 11 patients (32%). There were no differences in age at transplantation, immunosuppressive drugs, or follow-up period between the DSA-positive and DSA-negative patients. The rate of positive pre-transplant complement-dependent cytotoxicity crossmatch was higher with class II DSA than without, although the difference was not statistically significant.

CONCLUSIONS

The utility of screening for class I DSA was insignificant in the long-term follow-up of pediatric liver transplant recipients. The prevalence of class II DSA was relatively high; therefore, screening for class II DSA might be justified, although a follow-up survey of the association between post-transplant class II DSA and the long-term clinical course needs to be conducted.

Myocardial protection of the pressure overload hypertrophied heart in human cardiac surgery by acceleration of anaerobic glycolysis

BACKGROUND

Because of the decreased tolerance to ischemia and increased reperfusion injury in hypertrophied myocardium, myocardial hypertrophy is a well known risk factor for cardiac surgery. We have previously demonstrated in a left ventricular hypertrophy (LVH) model that a highly buffered cardioplegic solution (HBS) that provided glucose as a substrate and promoted anaerobic glycolysis during ischemia afforded superior myocardial protection when compared to standard formulations. And we reported the superiority of this cardioplegia in human cardiac surgery.

METHODS

In this study, 16 patients with aortic stenosis (AS) and LVH receiving HBS were reviewed and compared to another patient group with AS and LVH who received either cold blood cardioplegia (CBC; n=5) or glucose insulin potassium (GIK; n=6).

RESULTS

Postoperative cardiac index was better in the HBS group than the other two groups with similar or lower catecholamine. CK-MB was lower in HBS group than GIK group, but this was not significant. Only one DC cardioversion was required in the HBS group, whereas 2 DC in the CBC group and total 7 DC in the GIK group.

CONCLUSIONS

We found that histidine buffered cardioplegic solution provided comparable or better pump performance after surgery with relatively lower inotropic requirement, less DC cardioversion and homologous blood requirements for left ventricular hypertrophied heart associated with aortic stenosis.

Preoperative cerebrovascular screening before cardiovascular surgery in a high risk area of cerebrovascular events in Japan

BACKGROUND

Cerebrovascular disease and cervical artery diseases are potentially treatable conditions that are associated with an increased incidence of stroke after cardiac surgery. This prospective study was designed to determine the prevalence of cerebrovascular diseases in the high risk population of cerebrovascular event including some young patients in Japan and establish the strategy for cardiac surgery of patients with cerebrovascular disease.

METHODS

100 (71 male, 29 female) of 126 consecutive patients undergoing cardiac surgery under cardiopulmonary bypass were screened for the presence of cerebrovascular disease by intra-arterial angiogram.

RESULTS

In seven patients angiographic evaluation disclosed some evidence of cerebrovascular disease for 50% or greater stenosis or cerebral aneurysm. Preoperative 99mTc-Hexamethyl propylene amino oxime (99mTc-HMPAO) single emission computed tomography (SPECT) with combination of balloon arterial occlusion test provided detailed information of cerebral ischemic tolerance and reliable decision making for surgical repair of cerebrovascular disease. No deaths were recorded and a small stroke in one patient.

CONCLUSIONS

We concluded that cerebrovascular screening in patients with cardiovascular disease may be requested in a high risk population of cerebrovascular events.

Superior myocardial protection with a new histidine-buffered crystalloid cardioplegic solution in clinical trial

BACKGROUND

Blood cardioplegia has been widely accepted in clinical cardiac surgery based on its excellent oxygen delivery and pH buffering capacity. To further conserve blood during clinical cardiac surgery, we formulated a new crystalloid cardioplegic solution containing histidine (100 mol/L) as the pH buffering agent.

METHODS

Sixty patients being applied Histidine Buffered Solution (HBS) (n = 27) or Cold Blood Cardioplegic solution (CBC) (n = 33), both at 4 degrees C, were studied prospectively. Pre- and post-bypass left-ventricular (LV) volume was measured by echocardiography. With a ventricular pressure catheter, LV pressure-volume loops were constructed to determine the slope of the end-systolic pressure-volume relationship (Emax) without inotropes.

RESULTS

There were no postoperative deaths in either group. Thirty minutes after reperfusion Emax was significantly better in the HBS group than in the CBC group (6.0 +/- 1.0 mmHg/cm3 vs 3.7 +/- 0.8 mmHg/cm3). Cardiac Index was also significantly higher in HBS group than in CBC group with lower inotropic requirement. Homologous blood transfusion was avoided in 64% of the patients receiving HBS versus 48% of the patients with CBC.

CONCLUSIONS

We conclude that the new histidine-buffered cardioplegic solution provides effective protection with excellent recovery of pump performance in clinical open heart surgery.

[Histidine buffered cardioplegic solution (HBS) provides effective myocardial preservation with wider safety margin in patients with prolonged ischemia]

Increasingly complex techniques of cardiac surgery often require prolonged myocardial ischemia. We previously reported a better myocardial preservation with histidine containing cardioplegia (HBS) in human open heart surgery. To see a safety margin of this cardioplegia for prolonged myocardial preservation, this study was retrospectively done. One hundred twenty-six patients received either intermittent multidose (20-30 minute) cold blood cardioplegia (CBC) plus topical cooling (aotric cross clamp time (ACC) < 120 minutes, n = 63) or HBS (n = 63). HBS group was divided into two groups with either short ACC (< or = 120 minutes, HBS-S, n = 46) or long ACC (> 120 minutes, HBS-L, n = 17). Cardiac index (C.I.) and dopamin/dobutamine requirement were measured 3, 6, and 12 hours post-bypass. Incidence of homologous blood transfusion was also studied. There was two deaths due to LOS in HBS-S group; four patients in HBS group required 5 DC cardioversion, whereas six patients required a total of 12 DC cardioversion in CBC group. Functional recovery were significantly better with significantly lower inotropic requirements in HBS-S group than CBC group and HBS-L group. Although preoperative ejection fraction and C.I. were significantly lower in HBS-L group, post-operative cardiac function and inotropic requirements in HBS-L was comparable to that seen in CBC group. We conclude that the highly buffered histidine crystalloid cardioplegia solution provides effective myocardial preservation with a wider safety margin for prolonged myocardial preservation in open heart surgery.

Regional cerebral blood flow evaluated by 99mTc-HMPAO-SPECT in patients with axillo-axillary bypass for subclavian steal syndrome

BACKGROUND

Clear evidence of cerebral blood circulation has not been shown after axillo-axillary bypass surgery in patients with subclavian steal syndrome.

METHODS

We investigated the cerebral circulation and blood flow in 3 patients receiving axillo-axillary bypass by RI angiography using 99mTc-dl hexamethyl propylene amine oxime (99mTc-HMPAO). Two patients had vertebral basilar cerebral symptoms which were related to decreased cerebral blood flow evidenced by 99mTc-HMPAO.

RESULTS

After the correction, cerebral symptoms disappeared and improved cerebral blood circulation detected by 99mTc-HMPAO-SPECT.

CONCLUSIONS

We concluded that axillo-axillary bypass was a fairly effective procedure to improve cerebral blood circulation evidenced by 99mTc-HMPAO-SPECT.

[A clinical application of histidine buffered cardioplegia]

Blood cardioplegia has been widely accepted due to better oxygen delivery, pH buffering and free radical scavenge. We have found that a crystalloid cardioplegia solution formulated to accelerate anaerobic glycolysis with high buffering capacity. To conserve blood cardioplegia, we formulated a crystalloid cardiopletia containing 100 mM histidine for buffering. This cardioplegia (HBS) was compared to cold blood cardioplegia in patients requiring open heart surgery. Eighty patients including HBS (n = 28), and CBC (n = 40) were involved in this study. Left ventricular end-systolic elastance (Emax; mmHg/cm3) was evaluated pre- and postoperatively. Cardiac index and inotropic requirement were also monitored at 1, 3, and 12 hours after cardiopulmonary bypass. There was no death in either group. All hearts returned to previous rhythm in HBS group, whereas total 12 DC cardioversions were requested in 6 patients. Emax was significantly higher in HBS group (5.2 +/- 0.6 mmHg/cm3) than in CBC group (3.4 +/- 0.4 mmHg/cm3). Cardiac index was also significantly higher in HBS group postoperatively than in CBC group with lower inotropic requirements. We conclude that histidine containing crystalloid cardioplegia provides excellent recovery of cardiac performance with lower inotropic requirements in open heart surgery. The ease of use, and lack of blood are other important advantages of this crystalloid cardioplegia.

Purulently infected abdominal aortic aneurysm: in situ reconstruction with transmesocolic omental transposition technique

A new omental transposition technique was applied to a patient who underwent resection and in situ reconstruction of purulently infected abdominal aortic aneurysm to prevent recurrent retroperitoneal and graft infection. After wide separation from the transverse colon, the omental pedicle was transposed to the infrarenal retroperitoneal space through an opening of the transverse mesocolon to wrap the prosthetic graft and fill the infected space. The postoperative course was uneventful without any sign of recurrent infection in follow-up lasting 8 months. The authors' experience suggest that this 'transmesocolic' technique is an effective modality for critically ill patients with infected abdominal aorta.

[Heart failure due to severe myocardial calcification--a rare complication after irradiation on the chest wall]

A 28-year-old female who had had irradiation on the chest wall at the age of 5 as a remedy for keroid granulation after burn, recently developed congestive heart failure. Severe tricuspid regurgitation was demonstrated by echocardiography with a certain calcification in the cardiac shadow on chest radiogram. Calcified right ventricule and ventricular septum were noticed operatively, which disturbed ventricular motion and also caused tricuspid valve deformity. These calcified myocardium apparently corresponded with the irradiation field. After tricuspid valve replacement, she regained physical activity satisfactorily without congestive heart failure. Because she had no other known causes of cardiac calcification such as hypercalcemia, myocarditits, myocardial infarction or renal diseases, irradiation on the chest wall could be responsible for the severe myocardial calcification.

[A case of constrictive pericarditis--adjuvant techniques of operation and evaluation of the perioperative cardiac function]

A 43-year-old male diagnosed as constrictive pericarditis with dyspnea, fatigability and substantial pericardial calcification on chest roentgenogram underwent pericardiectomy through median sternotomy. The heavily calcified pericardium which was adherent to the anterior and diaphragmatic surface of the heart was successfully resected by the combined use of ultrasonic surgical aspirator (CUSA) and argon beam coagulator (ABC). Intraoperative bleeding was minimal because the adhesion between the pericardium and myocardium, coronary arteries or inferior vena cava were easily dissected with CUSA. Intraoperative hemostasis was also satisfactory with ABC. Perioperative measurements of right ventricular ejection fraction were also effective in evaluating the right ventricular function.

[Blunt disruption of the brachiocephalic artery]

A 59-year-old female having the disrupted brachiocephalic artery (BCA) and multiple bone fractures caused by a traffic accident was transferred to our hospital in a hypovolemic shock status with a wide mediastinum on the chest radiograph. Intraarterial digital subtraction angiography was effective in confirming the bleeding site of the artery. The patient underwent an urgent operation 4 hours and 22 minutes after admission. Through median sternotomy the BCA was simply clamped, followed by a direct suture repair of the 2/3-circumferential transection on the proximal portion of BCA. The patient had an uneventful postoperative course without any neurological complications.

[A case report of combined aortic and mitral regurgitation associated with ankylosing spondylitis]

We reported a case of ankylosing spondylitis which successfully underwent aortic valve replacement for combined aortic and mitral regurgitation. A 42-year-old man was admitted with symptoms of shortness of breath and anginal pain. He was previously diagnosed ankylosing spondylitis by an orthopedician A grade III/VI to and fro murmur was audible at the left sternal border. Retrograde aortography revealed severe aortic regurgitation and mild mitral regurgitation. Cardiac catheterization showed moderately pulmonary hypertension and high pulmonary artery wedge pressure. He underwent aortic valve replacement with SJM prosthetic valve. His postoperative course was uneventful. In Japan, ankylosing spondylitis is rare disease, and cardiac lesions associated with these conditions is seldom met to us. The surgical problems and management of these lesions are discussed.

[A case of chondrosarcoma originating from the left third rib]

Chondrosarcoma of rib origin is rare in Japan. A 51-year-old man came to our hospital with chest pain and coin lesion in the left superior part of the chest X-ray film. It was suspected to be the posterior mediastinal tumor based on CT and MRI. Operation was done to remove the tumor and the histological diagnosis was chondrosarcoma. The tumor measured 2.5 x 2.6 x 2.2 cm arising from the posterior portion of the left third rib. Combined resection of descending aortic adventitia was done. The patient is doing well without symptoms of recurrence 15 months after operation.

Apico-aortic conduit bypass operation in a patient with calcified ascending aorta due to Werner's syndrome

A 53-year-old Japanese man with Werner's syndrome underwent successful apico-aortic conduit bypass operation. Preoperative examination showed severe calcification in the aortic root and ascending aorta. A composite graft was implanted from the left ventricular apex to the descending thoracic aorta with femoro-femoral bypass. To our knowledge, this case is the first surgical correction of a cardiac lesion in a patient with Werner's syndrome.