Kiyoshige Inui

Optimal blood flow for cooled brain at 20°C

Abstract Background . Optimal conditions for deep hypothermic perfusion and protective brain blood flow remain unclear. Methods . Dogs (n = 52) underwent 120 minutes of cardiopulmonary bypass at 20°C with perfusion flow rates of 2.5, 5, 10, 20, 40, and 100 mL · kg −1 · min −1 . We examined the effect of the various flow rates and different perfusion pressures on brain blood flow, metabolism, and intracellular pH. Results . The brain was ischemic and acidotic when the perfusion flow rate was less than 5 mL · kg −1 · min −1 and pressure was less than 10 mm Hg. When perfusion pressure was higher than 10 mm Hg, cerebral cortex blood flow was more than 9 mL · 100 g −1 · min −1 and intracellular pH, higher than 6.95. The cerebral metabolic rate for oxygen decreased at a flow rate of 2.5 mL · kg −1 · min −1 . The cerebral metabolic ratio of glucose to oxygen and the cerebral vascular resistance were lowest when perfusion pressure was 10 to 30 mm Hg. Full-flow (100 mL · kg −1 · min −1 ) perfusion caused paradoxical brain acidosis; a flow of 40 mL · kg −1 · min −1 provided the best results. Conclusions . Both extremely low-flow perfusion and excessive perfusion cause brain acidosis. Low-flow perfusion at a pressure of 20 mm Hg provides cerebral vasorelaxation and aerobic metabolism during operations at 20°C.

A clinical study of postoperative infections following open-heart surgery: occurrence and microbiological findings in 782 cases.

A total 782 consecutive patients underwent open-heart surgery with CPB between January, 1979 and December, 1988, at the Yamagata University Hospital. We assessed the incidence of postoperative infections in relation to age, the duration of surgery and antibiotic prophylaxis, and examined the causative organisms, after which the types of infecting flora were compared between the 1st period, from 1979 to 1983 and the 2nd period, from 1984 to 1988.Postoperative infection occurred in 104 of the 782 patients (13.3 per cent); in the form of a wound infection in 41 (5.2 per cent), pneumonia in 33 (4.2 per cent), urinary tract infection in 9 (1.2 per cent), prosthetic valve endocarditis in 6 (0.8 per cent), and other infections in 15 (1.9 per cent). Patients aged under 12 months or over 60 years showed a higher incidence of infection, being 17.4 per cent and 19.2 per cent, respectively. Patients who underwent an operation of over 8 hours duration also had a significantly higher incidence compared to those whose operation time was less than 4 hours, being 32.9 per cent and 6.3 per cent, respectively (p<0.0001). There was no significant difference in the incidence of postoperative infection between patients given or not given preoperative prophylaxis. A total 123 species of organisms were isolated from the 104 patients, 52.8 per cent being gram-negative bacteria (GNB), and 43.9 per cent grampositive bacteria (GPB), and a remarkable increase in the incidence of GPB was seen in the 2nd period compared to the 1st period from 31.7 per cent to 50.0 per cent.There has been a recent increase in the number of high risk patients compromised by the severity of an underlying disease. Thus, to control infection, the surgical environment and aseptic technique seem more important than antibiotic prophylaxis.

Minimized mortality and neurological complications in surgery for chronic arch aneurysm: axillary artery cannulation, selective cerebral perfusion, and replacement of the ascending and total arch aorta.

Abstract  Objective: Cerebral complication is still a major concern in surgery for arteriosclerotic aortic arch disease. For preventing this complication, axillary artery cannulation, selective cerebral perfusion, and replacement of the ascending and arch aorta were applied to thoracic aortic aneurysm involving aortic arch. Method: From May 1999 to July 2002, consecutive 39 patients with true aneurysm (29 patients) or chronic aortic dissection (10 patients) involving aortic arch underwent replacement of the ascending and arch aorta with an elephant trunk under hypothermic cardiopulmonary bypass through the axillary artery cannulation and selective cerebral perfusion. The brain was continuously perfused without any intermission through the axillary artery. Concomitant operation included coronary artery bypass grafting (CABG) in two patients, aortic valve replacement (AVR) in one, Bentall operation in two, mitral valve replacement (MVR) in one, and aortic valve sparing operation in one. Patient age at operation was 40–84 (72 + 9) years and 24 of them were older than 70 years of age. Results: There was one operative death (2.5%) due to bleeding from the left lung, and one hospital death due to respiratory failure. Postoperative permanent neurological dysfunction was found in one patient (2.5%). Two patients presented temporary neurological dysfunction (5%). Thirty‐six of the 39 patients were discharged from hospital on foot. Conclusion: Continuous perfusion through the axillary artery with selective cerebral perfusion and replacement of the ascending and arch aorta may minimize cerebral complication leading to satisfactory results in patients with chronic aortic aneurysm involving aortic arch.

Retrograde cerebral perfusion: experimental approach to brain oedema.

Retrograde cerebral perfusion is used during aortic surgery as an adjunct to profoundly hypothermic circulatory arrest.1–3 Although it may protect the brain and extend the safe period of circulatory arrest, brain oedema is a possible side-effect. However, whether retrograde cerebral perfusion causes brain oedema or not has not been shown. Also, it is not known what causes brain oedema after retrograde cerebral perfusion, if it does: brain ischaemia, intracranial hypertension, or both during retrograde cerebral perfusion? To investigate these questions, we designed the present study, using a developed experimental model with simultaneous sagittal sinus and superior vena caval perfusion.4

Concomitant David’s operation and total arch replacement for acute type A aortic dissection

A 61-year-old man complained of chest pain and developed congestive heart failure due to massive acute aortic regurgitation. Computed tomographic scan demonstrated Stanford type A aortic dissection from the aortic root to common iliac arteries. Davids aortic valve sparing operation and total aortic arch replacement were applied to the patient, because the aortic dissection was extended into two aortic commissures and all arch vessels, though the tear was present at the proximal ascending aorta. The surgery was well tolerated without any significant complication.

Bentall operation for a child with Marfan syndrome: a case report.

Abstract Children with Marfan syndrome rarely undergo surgery for annuloaortic ectasia and aortic regurgitation in the first decade. A 7‐year‐old girl presented with congestive heart failure due to severe aortic regurgitation associated with annuloaortic ectasia (6 cm). She also had funnel chest. She underwent a Bentall operation and sternal turn‐over with a satisfactory result. Since the aortic valve cusps had rolled edges, the aortic valve was not spared. Histology of the aortic valve cusps showed myxoid degeneration and fragmentation of elastic fibers.

Experience of 10 Cases of Left Ventricular Free Wall Rupture after Acute Myocardial Infarction.

1987年1月より1991年1月までに当院CCUに収容された急性心筋梗塞症例372例のうち10例 (2.7%) に左室自由壁破裂の発症を認めた. 10症例中亜急性型3例と慢性型2例の計5例を救命した. 高齢者, 女性, 初回梗塞が危険因子と考えられた. PTCA後の再疎通が破裂発症の誘因である可能性があるが, PTCA施行非施行群間で発症率に差はみられなかった. しかし, PTCA非施行群の平均年齢が有意に高く, PTCA非施行破裂発症例のなかに自然再疎通例があることを考慮した場合, PTCA等による再疎通は破裂発症の一誘因と考えられた. 急性型の救命は困難であり, 危険因子からみた high risk group に対する重点的予防が重要と考えられた. 出血部周囲が脆弱で, 梗塞範囲が把握しにくいことより, 亜急性型の一部および慢性型に対する修復法として, 破裂部位直接縫合よりも fibringlue-oxycellulose fixation 法が有用と考えられた.