STA-MCA anastomosis in patients with skull base tumours involving the internal carotid artery—Haemodynamic assessment by ultrasonic Doppler flowmeter

Summary The role of superficial temporal artery -middle cerebral artery (STA-MCA) anastomosis was investigated with an ultrasonic Doppler flowmeter in 3 patients with sphenoid ridge meningiomas and one with a parasellar malignant teratoma, all of which involved the intracranial internal carotid artery. The intraoperative Doppler flow study revealed a remarkable increase in flow volume of the STA after trial occlusion of the middle cerebral artery in one case and permanent occlusion in two cases. These results substantiate the effectiveness of STA-MCA anastomosis. We also discuss surgical and other contrivances for obtaining sufficient blood supply from this bypass to prevent cerebral ischaemia in the acute phase after elective or accidental occlusion of a major cerebral artery. This is the first report of STA-MCA anastomosis in cases with brain tumour.     

Improvement of global cerebral blood flow after STA-MCA bypass in a patient with bilateral occlusion of the internal carotid artery: Effect of surgery or natural course?

A xenon-CT examination was performed on a patient who had received a STA-MCA bypass. Evaluation of cerebral blood flow (CBF) pre- and postoperatively shows a postoperative increase of about 60%.During manual compression of STA, a decrease of 20% was observed so that one third of the total CBF increase could be attributed to anastomosis. The remaining two thirds may originate from the natural collateral circulation.     

Superficial temporal artery — Middle cerebral artery anastomosis for acute cerebral ischemia: The effect of small augmentation of blood flow

Summary In order to evaluate the effectiveness of acute cerebral revascu-larisation, we conducted a review of 70 patients with acute arterial occlusion or severe stenosis. Of these, 35 underwent emergency superficial temporal artery — middle cerebral artery (STA-MCA) anastomosis (surgical group) and the other 35 were treated conservatively (non-surgical group) at different times. Statisticial analysis indicated that the two groups were homogeneous for the prognostic indicators. Seven days after admission, neurological symptoms and signs improved in 43% of patients in the surgical group and in 29% of the non-surgical group, however, this difference was not significant. The ratios of independent life at 3 months were 51% and 31%, respectively (not significant). Subgroup analyses indicated that final outcomes for patients with mild to moderate paresis on admission were significantly better in the surgical group than in the non-surgical group (94% vs. 53%, p < 0.01). The ratios of haemorrhagic infarction, neurological worsening, and mortality were comparable between the two groups. Time of ischaemia is a less important factor in the criteria for surgical selection. Acute revascularisation in selected patients does improve a natural course and could be a therapeutic option for acute cerebral ischaemia.     

Management of giant serpentine aneurysms of the middle cerebral artery — Review of literature and report of a case successfully treated by STA-MCA anastomosis only

Summary Thirty-eight cases of giant serpentine aneurysms (GSA), including 17 GSA of the middle cerebral artery (MCA), were reviewed in the literature. The treatment possibilities of GSA of the MCA are discussed together with our own case who was a 39-year-old male with a GSA of the right MCA and was treated only by STA-MCA anastomosis. The pathogenetic mechanism of progressive enlargement of the aneurysm is also discussed.     

Extracranial-intracranial arterial bypass in the treatment of inoperable giant aneurysms of the internal carotid artery

Summary A case of a giant aneurysm of the internal carotid artery (ICA) was treated with ICA ligation and extracranial-intracranial arterial bypass. The anastomosis was done before full occlusion of the cervical ICA, and the patient was followed with serial angiographic studies. The result obtained and the data from the literature of the last four years are discussed.     

Two cases of spontaneous occlusion of the internal carotid artery due to a giant intracranial internal carotid artery aneurysm

Although spontaneous thrombosis of a giant intracranial aneurysm is comparatively common, its parent artery occlusion is rare. Recently we experienced two cases in which spontaneous thrombosis of giant intracranial internal carotid artery aneurysm and occlusion of its parent artery were occurred. Case 1. A 49-year-old man, complaining esotropia was referred to us by an ophthalmologist. He had no particular past history. Neurological examination revealed left oculomotor, abducens palsy and disturbance of left trigeminal first branch. CT scan revealed a round high density mass in the left middle fossa. The size was 3 cm in diameter. Left CAG revealed severe stenosis of left internal carotid artery and in delayed phase, faint shadow was seen near posterior clinoid process. MRI revealed a high intensity mass of the intraaneurysmal thrombus in the left middle fossa with small low intensity area indicating residual lumen. With conservative treatment, the symptom was gradually improved and one month after admission, complete occlusion of the left internal carotid artery was seen by angiography. The patient returned to his previous occupation. Case 2. A 21-year-old man was admitted to our hospital complaining dysarthria and left hemiparesis. He had been diagnosed as left internal carotid giant aneurysm 5 years before when he had suffered from right visual disturbance. Neurological examination revealed left hemiparesis and dysarthria. CT scan revealed high density mass which extended from the base of the right middle fossa to the third ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intolerable pulse-synchronous tinnitus caused by occlusion of the contralateral common carotid artery

Summary A case with severe pulsatile tinnitus of the left side caused by occlusion of the right common carotid artery was reported. Tinnitus in this case was supposed to be due to the rich blood flow of the external carotid systems developed as collateral routes resulting from the occlusion of the right common carotid artery. It subsided with the establishment of a bypass using a vein graft between the ascending aorta and the residual patent portion of the right common carotid artery.     

Clinical outcome of standard extracranial-intracranial bypass surgery in patients with symptomatic atherosclerotic occlusion of the internal carotid artery

Summary Objective. In this retrospective study we wanted to determine the role of cerebral revascularization in patients with symptomatic occlusive cerebrovascular disease. Special emphasis was put on subsequent cerebrovascular events, benefit in neurological functioning and bypass patency, as evaluated during the follow-up period.Methods. A total of 73 superficial temporal artery to the middle cerebral artery bypasses were performed on 67 patients from 1986–2000. All patients exhibited a symptomatic occlusion of the internal carotid artery verified by angiography. All patients in our group were refractory to medical treatment. 65 patients (69 bypasses) with a mean age of 61 years (range: 38–79 years) were followed up over an average time of 44 months (range: 1.5–150 months).Results. The peri-operative morbidity rate was 3% with no mortality. 55 patients (85%) had no further cerebrovascular events after surgery, and only 7 (11%) patients experienced another cerebrovascular event. 57 (88%) patients showed an improvement of symptoms after surgery and only 1 patient fared worse during the follow-up peroid due to a stroke he suffered two years after bypass surgery. 90% of all bypasses remained patent during the follow-up.Conclusions. Although bypass surgery for occlusive cerebrovascular disease is still controversial, our retrospective study suggests both an improvement of symptoms and signs and a risk-reduction for future cerebrovascular events after surgery.     

Current strategies for the treatment of intracranial atherosclerotic internal carotid artery stenosis

We evaluate the current literature regarding treatment of intracranial atherosclerotic disease, with particular emphasis on emerging medical, surgical, and endovascular trials. A MEDLINE and PubMed search of the literature related to intracranial atherosclerotic disease was performed. Articles which discussed medical, surgical, and endovascular therapies were reviewed. Currently, best medical management of intracranial atherosclerotic stenosis consists of aspirin therapy. Despite this, a significant percentage of patients with high-grade stenoses experience recurrent stroke soon after their initial event. Although previous randomized trials demonstrated no benefit to performing intracranial-extracranial bypass surgery in patients with intracranial atherosclerotic stenosis, current studies seem to suggest a benefit in a particular subset of these patients, specifically those with hemodynamic compromise. Endovascular therapy for intracranial atherosclerotic stenosis is in its infancy but is beginning to show technical promise. Nonetheless, real concerns exist regarding rates of in-stent restenosis, and large-scale follow-up studies must be completed before the true efficacy of endovascular therapies can be evaluated. Symptomatic intracranial atherosclerotic stenosis is associated with considerable morbidity and mortality. However, in a subgroup of patients, specifically those with high-grade stenoses and hemodynamic compromise, the risk of morbidity and mortality is significantly higher. It is this group of patients that would most benefit from more aggressive interventions, as best medical therapy still results in a significant rate of recurrent strokes. The emergence of improved surgical and endovascular techniques will be of particular importance in treating these high-risk patients.     

Endovascular management of carotid-cavernous fistula combined with ipsilateral internal carotid artery occlusion due to gunshot: contra-lateral arterial approach

Summary We hereby report the endovascular management of a posttraumatic caroticocavernous fistula combined with an occlusive ipisilateral carotid dissection; this was successfully managed by a contra-lateral arterial approach via the anterior communicating artery.     

Cuff occlusion on the left upper arm increases flow of the left internal mammary artery and bypass flow to the left anterior descending artery

Purpose  Changes in vascular resistance in the left forearm may affect the flow of left internal mammary artery (LIMA)- to left anterior descending artery (LADA) bypass, because the LIMA is a major branch of the subclavian artery. We studied the effects of occlusion of the left upper arm on blood flow of LIMA-to-LADA bypass in patients undergoing coronary artery bypass grafting (CABG). Methods  In ten patients, the blood volume shed from LIMA with the distal end open (LIMA free flow) was stored for 1 min before and during cuff inflation in CABG surgery. LIMA-LADA bypass flow was measured with ultrasonic flow-metry before and after cuff inflation on the left upper arm in an other ten patients. Mean arterial blood pressure (MAP), heart rate (HR), and electrocardiograms (ECGs) were monitored throughout the studies. Results  LIMA free flow (ml·min⁻¹) increased from 50.3 ± 7.1 to 60.9 ± 8.4 (P < 0.01) at the end of 1-min cuff inflation. LIMA-LADA bypass flow (ml·min⁻¹) increased from 31.4 ± 3.7 to 39.7 ± 4.0 (P § 0.05) at 1 min after cuff inflation. MAP, HR, and ST segments on ECGs did not show any significant changes related to measurement times. Conclusion  LIMA-LADA bypass flow increased after cuff inflation on the left upper arm and returned to the baseline values after cuff deflation. Anesthesiologists should be aware of this relationship between local vascular resistance and bypass flow for the evaluation of LIMA-LADA anastomosis.     

Stump pressure as a guide to the safety of permanent occlusion of the internal carotid artery

Summary Does the absolute value of the stump pressure (post-occlusion back pressure) become a useful index of a good collateral circulation?The authors continuously monitored the mean arterial pressure before, during and after 20-minute balloon test occlusion in 24 patients. The stump pressure was then compared with the results of^{99 m}Tc-hexa-methyl propyleneamine (^{99 m}Tc-HMPAO) single photon emission computed tomography (SPECT) performed after 20 minutes of test occlusion.Patients who failed to tolerate even brief periods of carotid occlusion and showed asymmetric decreases in cerebral blood flow (CBF) on SPECT were divided into high and moderate risk groups. Those with no significant change in CBF on the occluded side formed the minimum risk group.Mean stump pressure was over 50 mmHg in three of a total of 13 patients in the high and moderate risk groups, and below 50 mmHg in two of the 11 patients in the minimum risk group. The ratios of the initial mean stump pressure to the pre-occlusion mean arterial pressure (%) and of the final mean stump pressure at the end of occlusion to the post-opening mean arterial pressure (%) did not exceed 58% in any patient in the high and moderate risk groups, and were at least 60% in all patients of the minimum risk group.Maintenance of a mean stump pressure of 60% or more of the mean systemic pressure during test occlusion may be a more useful index of a good collateral circulation than the absolute value of mean stump pressure.     

静动脉二氧化碳分压差在冠状动脉旁路移植术围术期心输出量评估中的应用观察

目的 探讨经过术后上腔静脉血氧饱和度(central venous oxygen saturation,ScvO2)＞70％的冠状动脉旁路移植术(coronary artery bypass grafting,CABG)患者是否能够应用静动脉二氧化碳分压差(central venous atrial carbon dioxide partial pressure,Pcv-aCO2)作为围术期心输出量评估指标. 方法 142例术后早期ScvO2＞70％的CABG患者,根据术后即刻Pcv-aCO2是否≥6 mm Hg(1 mm Hg=0.133 kPa),分为高Pcv-aCO2组和低Pcv-aCO2组.观察2组患者在术后即刻(T0)、8(T8)、12(T12)、24(T24)、48 h(T48)时的血流动力学指标,灌注指标,心功能状态,恢复情况. 结果 64例患者为高Pcv-aCO2组,余78例患者为低Pcv-aCO2组.两组患者入组时低Pcv-aCO2组动脉血乳酸(lactate,Lac)、心指数(cardiac index,CI)、血管活性药物评分分别为(3.7±1.3) mmol/L、(3.54±0.88) L/m2、(9±5),高Pcv-aCO2组Lac、CI、血管活性药物评分分别为(6.5±2.5) mmol/L、(2.79±0.68) L/m2、(13±6),两组比较差异有统计学意义(P＜0.05).两组患者入组后均在术后8h出现CI下降,Lac及血管活性药物评分上升,低Pcv-aCO2组在T12、T24、T48时CI逐渐上升,Lac及血管活性药物评分下降;高Pcv-aCO2组在T24时才出现CI逐渐上升,Lac及血管活性药物评分下降,低Pcv-aCO2组CI明显高于高Pcv-aCO2组(P＜0.05);低Pcv-aCO2组Lac、血管活性药物评分下降时间早于高Pcv-aCO2组(P＜0.05).低Pcv-aCO2组主动脉内球囊反搏(intra-aortic balloon pump,IABP)应用率为3.8％、呼吸机辅助时间为(34±22)h、住重症监护室(ICU)时间为(106±26)h、呼吸衰竭发生率5.1％、肾功能衰竭发生率1.3％,高Pcv-aCO2组IABP应用率为12.5％、呼吸机辅助时间为(48±27)h、住ICU时间为(136-45)h、呼吸衰竭发生率17.2％、肾功能衰竭发生率1.3％,两组比较差异有统计学意义(P＜0.05). 结论 CABG患者术后早期Pcv-aCO2≥6mmHg提示心输出量不足,术后并发症的发生与早期高Pcv-aCO2水平有明显关系.