Radiation exposure to anaesthetists during endovascular procedures

Medical radiation exposure increases the likelihood of cataract formation. A personal dosimeter was attached to the left temple of 77 anaesthetists during 45 endovascular aortic aneurysm repairs and 32 interventional neuroradiology procedures. Compared with interventional neuroradiology, the median (IQR [range]) total radiation dose emitted by fluoroscopic equipment was significantly lower during endovascular aortic aneurysm repair (4175 (3127–5091 [644–9761]) mGy than interventional neuroradiology (1420 (613–2424 [165–10 840]) mGy, p < 0.001). However, radiation exposure to the anaesthetist's temple was significantly greater during endovascular aortic aneurysm repair (15 (6–41 [1–109]) μSv) than interventional neuroradiology (4 (2–8 [0–67]) μSv, p < 0.001). These data suggest that anaesthetists at our institution would have to deliver anaesthesia for ~1300 endovascular aortic aneurysm repairs and ~5000 interventional neuroradiology cases annually to exceed the general occupational limits, and ~10 000 endovascular aortic aneurysm repairs and ~37 500 interventional neuroradiology cases to exceed the ocular exposure limits recommended by the International Commission on Radiological Protection. Nevertheless, anaesthetists should be aware of the risk of ocular radiation exposure, and reduce this by limiting the time of exposure, increasing the distance from the source of radiation, and shielding.     

Assessment of regional wall motion using strain Doppler imaging during right ventricular bifocal pacing in a patient with severe congestive heart failure: a case report

A 79-year-old man presented with dilated cardiomyopathy and chronic atrial fibrillation. A DDD pacemaker was implanted due to sick sinus syndrome. His left ventricular ejection fraction was 23%. He was repeatedly admitted with congestive heart failure. Although cardiac resynchronization therapy was attempted, insertion of a pacing lead into the coronary sinus failed. Right ventricular bifocal pacing was done. The QRS width was shortened to 155 msec during bifocal pacing and 157 msec during right ventricular outflow pacing from 221 msec during right ventricular apical pacing. Heart failure was improved from New York Heart Association class III to II. Regional wall motion was assessed by strain of the myocardium. Bifocal pacing increased stroke volume due to improvement of longitudinal dyssynchrony of the septal and lateral walls. Bifocal pacing is effective for patients with severe congestive heart failure in whom biventricular pacing therapy has failed. Strain Doppler imaging is useful for the assessment of regional wall motion during cardiac pacing.     

Analysis of hepatofugal flow in portal venous system using ultrasonic Doppler duplex system

Blood flow directions of the portal trunk, splenic vein, and superior mesenteric vein were studied using an ultrasonic Doppler duplex system in 146 healthy adults, 132 patients with liver cirrhosis, 76 with hepatocellular carcinoma, 32 with idiopathic portal hypertension, 134 with chronic hepatitis, 18 with acute hepatitis, and 142 with other diseases. Spontaneous hepatofugal flow in one or more of the three vessels examined was detected in 14 patients. Spontaneous hepatofugal flow in the portal trunk was detected in three patients with liver cirrhosis. In two of these three patients, the hepatofugal flow in the portal trunk disappeared after medication. This is interesting, since hepatofugal flow may, in fact, be more common than we suspected in patients who, because of the severity of their disease, are not able to undergo invasive examination. Postoperative hepatofugal flow in the portal system was detected in 20 of 71 cases: 15/17 patients after interposition mesocaval shunting, 2/17 after distal splenorenal shunting, 2/31 after splenectomy, and 1/6 after splenic artery occlusion with steel coils. In more than half the cases of interposition mesocaval shunting (9/17 patients), blood flow in the portal trunk was hepatofugal. However, hepatopetal blood flow in the portal trunk was maintained in most cases of distal splenorenal shunting (13/17), showing the merits of this technique as a selective portosystemic shunt operation.     

Hemodynamics of splenic artery aneurysm

Blood flow volume of the portal venous system of 3 patients with splenic artery aneurysm, an uncommon disease, was measured using an ultrasonic duplex system. A huge increase in splenic blood flow volume was found in each case. A large portasystemic shunt through which the portal blood flowed hepatofugally was present in 2 cases. We suspect the shunt is partially responsible for an increase in splenic blood flow volume, which would lead to the formation of splenic artery aneurysm together with portal hypertension.     

Semiquantitative analysis of indocyanine green videoangiography for cortical perfusion assessment in superficial temporal artery to middle cerebral artery anastomosis

Background

Postoperative hyperperfusion may lead to severe neurological complications after superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis. However, there are no reliable modalities to predict the occurrence of postoperative hyperperfusion during surgery. The purpose of this study is to evaluate whether a semiquantitative analysis of indocyanine green (ICG) videoangiography could be useful in predicting postoperative hyperperfusion after STA-MCA anastomosis.

Methods

This study included seven patients who underwent STA-MCA anastomosis due to occlusive carotid artery diseases. During surgery, ICG videoangiography was performed before and after bypass procedures, and ICG intensity–time curves were semiquantitatively analyzed to evaluate hemodynamic changes by calculating maximum intensity, time to peak (TTP), and blood flow index (BFI).

Results

Maximum intensity significantly increased from 252.6?±?132.5 to 351.7?±?151.9 after bypass (p?<?0.001). TTP was significantly shortened from 12.9?±?4.4 s to 9.8?±?3.7 s (p?<?0.001). Furthermore, BFI significantly increased from 33.9?±?28.1 to 74.6?±?88.4 (p?<?0.05). Postoperative hyperperfusion was observed in five of seven patients 1 day after surgery. The ratio of BFI before and after bypass procedures was significantly higher in patients with postoperative hyperperfusion than those without, 2.5?±?1.1 and 1.5?±?0.4, respectively (p?=?0.013).

Conclusions

These findings suggest that semiquantitative analysis of ICG videoangiography is helpful in predicting occurrence of hyperperfusion after STA-MCA anastomosis in patients with occlusive carotid artery diseases.     

Effects of aliskiren-based therapy on ambulatory blood pressure profile, central hemodynamics, and arterial stiffness in nondiabetic mild to moderate hypertensive patients

J Clin Hypertens (Greenwich). 2012;00:000–000. ©2012 Wiley Periodicals, Inc. Aliskiren is a direct renin inhibitor that exerts its effect at the rate‐limiting step of the renin‐angiotensin system. This study was performed to examine the beneficial effects of aliskiren‐based antihypertensive therapy on the ambulatory blood pressure (BP) profile, central hemodybamics, and arterial stiffness in untreated Japanese patients with mild to moderate hypertension. Twenty‐one Japanese nondiabetic patients with untreated mild to moderate essential hypertension were initially given aliskiren once daily at 150 mg, and the dose was titrated up to 300 mg as needed. After 12 weeks of aliskiren‐based therapy, the clinic, ambulatory, and central BP values as well as brachial‐ankle pulse wave velocity (baPWV) were all significantly decreased compared with baseline (clinic systolic BP, 151±11 mm Hg vs 132±11 mm Hg; clinic diastolic BP, 91±13 mm Hg vs 82±9 mm Hg; 24‐hour systolic BP, 144±12 mm Hg vs 133±11 mm Hg; 24‐hour diastolic BP, 88±8 mm Hg vs 81±9 mm Hg; central BP, 162±16 mm Hg vs 148±14 mm Hg; baPWV, 1625±245 cm/s vs 1495±199 cm/s; P<.05). These results show that aliskiren, as a first‐line regimen, improves the ambulatory BP profile and may have protective vascular effects in Japanese nondiabetic patients with untreated mild to moderate essential hypertension.