Katsushi Kinouchi

Prevention of ischemia/reperfusion-induced pulmonary dysfunction after cardiopulmonary bypass with terminal leukocyte-depleted lung reperfusion

OBJECTIVE Pulmonary ischemia and reperfusion during routine open heart surgery with cardiopulmonary bypass can lead to pulmonary dysfunction and vasoconstriction, resulting in a high morbidity and mortality. We investigated whether ischemia/reperfusion-induced pulmonary dysfunction after full-flow cardiopulmonary bypass could be prevented by the infusion of leukocyte-depleted hypoxemic blood during the early phase of reperfusion (terminal leukocyte-depleted lung reperfusion) and whether the benefits of this method were nullified by using hyperoxemic blood for reperfusion. METHODS Twenty-one neonatal piglets underwent 180 minutes of full-flow cardiopulmonary bypass with pulmonary artery occlusion, followed by reperfusion. The piglets were divided into 3 groups of 7 animals. In group I, uncontrolled reperfusion was achieved by unclamping the pulmonary artery. In contrast, pulmonary reperfusion was done with leukocyte-depleted hyperoxemic blood in group II or with leukocyte-depleted hypoxemic blood in group III for 15 minutes at a flow rate of 10 mL/min/kg before pulmonary artery unclamping. Then the animals were monitored for 120 minutes to evaluate post-cardiopulmonary bypass pulmonary function. RESULTS Group I developed pulmonary dysfunction that was characterized by an increased alveolar-arterial oxygen difference (204 + or - 57.7 mm Hg), pulmonary vasoconstriction, and decreased static lung compliance. Terminal leukocyte-depleted lung reperfusion attenuated post-cardiopulmonary bypass pulmonary dysfunction and vasoconstriction when hypoxemic blood was used for reperfusion (alveolar-arterial oxygen difference, 162 + or - 61.0 mm Hg). In contrast, no benefit of terminal leukocyte-depleted lung reperfusion was detected after reperfusion with hyperoxemic blood (alveolar-arterial oxygen difference, 207 + or - 60.8 mm Hg). CONCLUSION Reperfusion with leukocyte-depleted hypoxemic blood has a protective effect against ischemia/reperfusion-induced pulmonary dysfunction by reducing endothelial damage, cytokine release, and leukocyte activation.

Reconsideration of Patient-Prosthesis Mismatch Definition From the Valve Indexed Effective Orifice Area

BACKGROUND The objective of this study was to reassess the validity of defining patient-prosthesis mismatch (PPM) in the aortic position on the basis of an indexed effective orifice area (iEOA) less than 0.85 cm(2)/m(2). METHODS From June 1996 to March 2008, 342 patients underwent aortic valve replacement with a Carpentier-Edwards Perimount valve. From the data collected, the transvalvular pressure gradient was determined by the modified Bernoulli equation, and EOA was calculated from the standard continuity equation. RESULTS The actuarial survival rate at 10 years after surgery was 84.0% +/- 8.2%. The prevalence of PPM was 6.1% when a projected iEOA less than 0.85 cm(2)/m(2) was defined as indicating significant PPM. There was no difference between patients with moderate PPM (85.2% +/- 9.8%) and patients without PPM (81.0% +/- 8.7%; p = 0.44). The relation between mean transvalvular pressure gradient and iEOA demonstrated a gentler slope than that reported previously. Postoperative mean transvalvular pressure gradient was 17.4 +/- 5.6 mm Hg and 14.5 +/- 5.6 mm Hg in patients with an iEOA less than 0.85 and 0.85 or greater, respectively. Most patients had a postoperative mean transvalvular pressure gradient more than 10 mm Hg regardless of PPM. CONCLUSIONS Our analysis suggested that an iEOA less than 2.0 cm(2)/m(2) might be the threshold for PPM, which should not be passed to achieve a low mean transvalvular pressure gradient (less than 10 mm Hg) with the Carpentier-Edwards Perimount valve. The implications of these findings include the necessity for reassessing the hemodynamic performance of each type of prosthesis when attempting to define PPM, to avoid residual significant transvalvular pressure gradient.

Ischemic postconditioning promotes left ventricular functional recovery after cardioplegic arrest in an in vivo piglet model of global ischemia reperfusion injury on cardiopulmonary bypass

OBJECTIVE An in vivo study of piglets on cardiopulmonary bypass was performed to determine whether postconditioning has a cardioprotective effect after cardioplegic arrest in large animals. METHODS Eighteen piglets were subjected to 90 minutes of cardioplegic arrest followed by 30 minutes of reperfusion. In 6 animals (control), there was no intervention at reperfusion. In 6 other animals, 6 cycles of unclamping and reclamping for 10 seconds each were done before reperfusion (postconditioning 10), whereas 3 cycles of unclamping and reclamping for 30 seconds each were performed in another 6 piglets (postconditioning 30). RESULTS Recovery of left ventricular contractility and diastolic function (percent of preischemic value) was significantly better in both postconditioning groups (contractility: 89.2% and 118.2; diastolic function: 142.3% and 120.4; in the postconditioning 10 and 30 groups, respectively) compared with the control (contractility: 46.1%; diastolic function: 218.5%). Recovery of global cardiac function (ventricular function curve analysis) was improved only in the postconditioning 30 group. Troponin-T release during reperfusion was significantly reduced in the postconditioning 10 group compared with all groups (plasma troponin-T was 0.58 ng/mL in postconditioning 10, 1.85 in postconditioning 30, and 2.54 in control). The myocardial lipid peroxide was significantly higher in the control group than in both postconditioning groups after reperfusion (199% vs 112% and 131%). CONCLUSIONS Both postconditioning algorisms promoted functional recovery after cardioplegic arrest in a large animal model along with the limitation of lipid peroxidation with or without the reduction of troponin-T release.

Long-Term Results of Triple-Valve Procedure

Triple-valve procedures are associated with high early and late mortality. We reviewed our experience in 25 patients who underwent combined mitral and aortic valve replacement with tricuspid valve repair or replacement between 1979 and 2004. The mean follow-up was 7.8 years (range, 10 days to 24.5 years). The mean age at operation was 52 years (range, 31 to 72 years). Four patients underwent triple-valve replacement and 21 had double-valve replacement and tricuspid annuloplasty. Perioperative mortality was 20% and late mortality was 24%. Cumulative survival, calculated taking perioperative mortality into account, was 71% ± 10% at 10 years and 36% ± 15% at 15 years after surgery. Only 1 of 20 perioperative survivors required re-operation for prosthetic valve dysfunction. Double-valve replacement with tricuspid annuloplasty offers satisfactory long-term survival with freedom from thromboembolism and re-operation.

Double switch operation for congenitally corrected transposition of the great arteries after two-staged pulmonary artery banding

We describe a case of congenitally corrected transposition of the great arteries (cc-TGA) successfully performed by the double switch operation after two-staged pulmonary artery banding (PAB). An eleven-year old boy diagnosed with cc-TGA underwent the first PAB at that age, followed by the second PAB one year later. Because of severe ventricular dysfunction and arrhythmia of the anatomic left ventricle, the intension of one-stage PAB was abandoned. Cardiac catheterization data from after the adequate second PAB provided the surgical indication for the anatomical correction and double switch operation (Senning+Jatene procedure) and this was successfully performed at age 14. Although cardioversion was required to treat supraventricular tachycardia in the early period after surgery, the patient was discharged from hospital and remains in good clinical condition at the last follow-up at 5 years with normal sinus rhythm and good biventricular function.

Inflammatory Response to Hyperoxemic and Normoxemic Cardiopulmonary Bypass in Acyanotic Pediatric Patients

Background: Hyperoxemic management during cardiopulmonary bypass (CPB) is still common, and there is no consensus about physiologic oxygen tension strategy (normoxemic management) during pediatric CPB. In this study, we compared the postoperative conditions and measures of inflammatory response among patients with acyanotic congenital heart disease subjected to either hyperoxemic or normoxemic management strategy during CPB. Methods: We studied 22 patients with a ventricular septal defect and pulmonary artery hypertension. The patients were divided into two groups. Group I (n = 9) received normoxemic management (PaO2 = 100-150 mm Hg) and group II (n = 13) received hyperoxemic management (PaO2 = 200-300 mm Hg) during CPB. There was no difference between groups with regard to age, body weight, duration of CPB, and aorta clamping time or preoperative pulmonary hypertension (pulmonary pressure/systemic pressure [Pp/Ps]). In each group, the blood samples to measure the cytokine levels were collected before and after the CPB. Results: Although we observed no statistically significant differences in postoperative intubation time, alveolar–arterial oxygen difference, creatine kinase MB level, and pulmonary hypertension (Pp/Ps) between group I (10.7 ± 13.4 hours, 197 ± 132 mm Hg, 148 ± 58.6 IU/L, 42.8% ± 22.1%, respectively) and group II (27.8 ± 36.5 hours, 227 ± 150 mm Hg, 151 ± 72.6 IU/L, 50.4% ± 16.0%, respectively), levels of median interleukin 6 and tumor necrosis factor α were lower in group I (129.8 and 17.0 pg/mL, respectively) than that in group II (487.8 and 22.5 pg/mL, respectively). Conclusion: During the CPB in acyanotic pediatric patients, normoxemic management can minimize the systemic inflammatory response syndrome associated with CPB. We can apply this physiologic oxygen tension strategy to surgical advantage during heart surgeries in acyanotic pediatric patients.

Reversal of oxidant-mediated biochemical injury and prompt functional recovery after prolonged single-dose crystalloid cardioplegic arrest in the infantile piglet heart by terminal warm-blood cardioplegia supplemented with phosphodiesterase III inhibitor

PurposeThe benefit of terminal blood cardioplegia (TWBCP) is insufficient after prolonged ischemia associated with inevitable oxidant-mediated injury by this modality alone. We tested the effects of TWBCP supplemented with high-dose olprinone, which is a phosphodiesterase III inhibitor, a clinically available compound with the potential to reduce oxidant stress and calcium overload. We evaluated the effects with respect to avoiding oxidant-mediated myocardial reperfusion injury and prompt functional recovery after prolonged single-dose crystalloid cardioplegic arrest in a infantile piglet cardiopulmonary bypass (CPB) model.MethodsFifteen piglets were subjected to 90 min of cardioplegic arrest on CPB, followed by 30 min of reperfusion. In group I, uncontrolled reperfusion was applied without receiving TWBCP; in group II, TWBCP was given; in group III, TWBCP was supplemented with olprinone (3 μg/ml). Myocardial performance was evaluated before and after CPB by a left ventricular (LV) function curve and pressure-volume loop analyses. Biochemical injury was determined by measurements of troponin-T and lipid peroxide (LPO) in coronary sinus blood.ResultsGroup III showed significant LV performance recovery (group I, 26.5% ± 5.1%; group II, 42.9% ± 10.8%; group III, 81.9% ± 24.5%, P < 0.01 vs. groups I and II), associated with significant reduction of troponin-T and LPO at the reperfusion phase. No piglets in group III needed electrical cardioversion.ConclusionWe concluded that TWBCP with olprinone reduces myocardial reperfusion injury by reducing oxidant-mediated lipid peroxidation, and it accelerates prompt and persistent LV functional recovery with suppression of reperfusion arrhythmia.

Congenital thoracoabdominal aortic aneurysm

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Modified Konno Operation for Aortic Valve Regurgitation after Arterial Switch Operation

動脈スイッチ手術(ASO)後の狭小大動脈弁輪を有する大動脈弁閉鎖不全症(AR)に対しては冠動脈パターン,大動脈-肺動脈関係など各症例の特徴に応じた弁輪拡大法の選択が不可欠である.ASO術後遠隔期のARに対するKonno法による弁輪拡大を用いた大動脈弁置換術(AVR)の1例を報告する.症例は4歳の女児,完全大血管転位症(TGA)II型の診断により生後10日目にASOを施行した.術後4年後に発症したIII度のARに対し主肺動脈切離後,肺動脈後壁から心室中隔へKonno切開を行い,大動脈弁輪を拡大し21mm SJM弁によりAVRを施行した.術後5年の現在良好に経過している.

Mid-Term Pulmonary Homograft Function for Right Ventricular Outflow Tract Reconstruction in the Ross Procedure.

海外では1980年代からhomograftが臨床応用されているが本邦での使用経験は希少である.今回Ross手術右室流出路再建にpulmonary homograftを用いた14例について検討した.Graft機能を心エコーによるpeak flow(PK),圧較差(PG),弁逆流について調べ,PGと患者の年齢,donor年齢,graft保存期間との相関関係も検討した.年齢は平均17.2歳,手術内訳はRoss手術10例,Ross-Konno手術4例,観察期間は23.1ヵ月であった.PK,PGはそれぞれ1.6±0.4m/s,11.9±5.2mmHgであった.弁逆流は1例にごくわずかに認めるのみであった.またPG-年齢,PG-donor年齢,PG-graft保存期間との間にはいずれも相関関係を認めなかった.23ヵ月の期間では,QOLに影響するような狭窄や弁逆流を認めず,右室流出路再建に用いる材質として優れていると考えられた.