【投稿論文：Original Article】 難治性高血圧症に対する脳神経減圧術の手術適応について

Introduction: Causal relationship between refractory essential hypertension（e-HTN） and neurovascular compression （NVC） at the rostral ventrolateral medulla（RVLM） has been well documented．However, an appropriate indication of surgical treatment for refractory e-HTN remains unclear．The purpose of this paper is to clarify the indication of microvascular decompression（MVD） for e-HTN．Clinical cases: The authors present four cases who underwent MVD for NVC at the RVLM．Preoperative magnetic resonance imaging revealed compression of the left vertebral artery（VA） at the ipsilateral RVLM in all four patients． All cases underwent MVD via the left lateral suboccipital approach and the left VA made indentation on the ipsilateral RVLM, and the distal part of VA was successfully transpositioned．In 2 patients who preoperatively showed high levels of plasma aldosterone and renin and/or urine norepinephrine, decompression surgery was effective to normalize blood pressure．In one of these 2 patients（49-year-old, female），long time suffering high blood pressure became completely normalized without taking any antihypertensive drugs at all and the other one（40-year-old, male） needed to take only a small amount of such drugs to control blood pressure for many years postoperatively．On the other hand, in 2 patients who even revealed NVC on neuroimaging study without showing elevated hormonal levels, complete normalization of blood pressure was not obtained postoperatively．Conclusion: To obtain successful surgical result of MVD for e-HTN, not only preoperative neuroimaging studies, but also hormonal examinations, i.e. renin-angiotensin-aldosterone system and catecholamine group in plasma and urine are mandatory．