Undergoing Aneurysm Surgery Research Articles

Shunt-dependent hydrocephalus and shunt failure rate in patients with aneurysmal subarachnoid hemorrhage in Korea.

Shunt-dependent hydrocephalus is a major complication of aneurysmal subarachnoid hemorrhage (SAH). Despite this, the factors influencing shunt dependency and shunt failure remain unclear. Therefore, the aim of this study was to estimate shunt dependency and failure rates and determine the contributing factors in patients with aneurysmal SAH using the Korean National Health Insurance database over a 13-year period. Patients with aneurysmal SAH aged > 18 years who underwent surgical procedures were included. Using the shunt surgery prescription data, the shunt-dependent hydrocephalus rate was evaluated according to sex, age, aneurysm location, and year of admission. Among patients who underwent shunt surgery, the shunt failure rate was estimated using surgical prescription data. A total of 57,030 patients with SAH who underwent aneurysm surgery were included. The overall raw rate of shunt-dependent hydrocephalus was 15.0% (8530/57,030). Age (HR 1.04, 95% CI 1.04-1.04; p < 0.001) and endovascular coiling (vs surgical clipping, HR 0.71, 95% CI 0.67-0.74; p < 0.001) were related to shunt-dependent hydrocephalus in the multivariate logistic regression analysis. Posterior circulation and anterior communicating aneurysms showed a high risk of shunt dependency. Among 8530 patients who underwent shunt surgery, the shunt failure rate was 11.3% (961/8530). Female sex (HR 1.18, 95% CI 1.01-1.39; p = 0.0324), age (HR 0.99, 95% CI 0.98-0.99; p < 0.001), early shunt placement (HR 1.25, 95% CI 1.08-1.47; p = 0.004) and lumboperitoneal shunt placement (HR 2.19, 95% CI 1.65-2.91; p < 0.001) were the risk factors for shunt failure in the multivariate logistic regression analysis. The rate of shunt-dependent hydrocephalus after aneurysmal SAH was 15.0% in this study using a medical claims database in Korea. The shunt surgery rate was highest in patients in their 60s and 70s. Shunt failure occurred in 11.3% of the patients, and a lumboperitoneal shunt was most related to the need for revision surgery.

Predictors of Atherosclerotic Change in Unruptured Intracranial Aneurysms and Parent Arteries During Clipping

To identify predictors of atherosclerotic change in aneurysms and parent arteries, and to retrospectively analyze outcomes from clipped aneurysms that showed atherosclerotic changes. Between May 2017 and April 2018, we collected a total of 151 clipping cases and reviewed records of operation videos to classify atherosclerosis by location (dome, neck of aneurysm, or parent artery). To identify predictors of atherosclerotic change in aneurysms, we analyzed baseline demographic characteristics, preoperative images, and Framingham Risk Scores (FRS). We also analyzed incomplete clipping cases according to atherosclerosis presence and location. This study cohort included 110 women (mean age, 59.3 ± 7.1 years) and 41 men (mean age, 55.9 ± 9.6 years). Atherosclerotic change was seen in 77 cases. FRS, diabetes mellitus, and aneurysm size were identified as independent risk factors for atherosclerotic change in multivariate logistic regression analysis. There were 11 incomplete clipping cases (7.2%). Among the 30 cases with atherosclerotic change in the neck were 10 cases of incomplete clipping (P < 0.001). FRS, diabetes mellitus, and aneurysm size as predictors of atherosclerosis in patients undergoing aneurysm surgery can help guide surgical decisions and performance.

Factors that Affect Postoperative Hydrocephalus Development in Aneurysmal Subarachnoid Hemorrhage: A Clinical Study.

Factors affecting the development of postoperative hydrocephalus patients who underwent surgery after aneurysmal subarachnoid hemorrhage were retrospectively assessed. 201 cases, who underwent aneurysm surgery in our clinic after subarachnoid hemorrhage between 2008 and 2013, were retrospectively assessed. Twenty-one cases with hydrocephalus development were retrospectively examined according to their age, gender, history (hypertension, alcohol, and smoking), blood type, the number and size of aneurysms, aneurysm localization, the presence of ventricular hemorrhage, baseline-final neurological diagnosis, Fisher grading system, history of vasospasm and meningitis. The initial neurological course and Hunt-Hess, and also final neurological course of the patients were evaluated according to World Federation of Neurosurgical Societies (WFNS) Grading Scale. Age, history of hypertension, aneurysm localization, Hunt-Hess grading, vasospasm, meningitis and Glasgow Outcome Scale (GOS) are determinative factors in hydrocephalus development due to subarachnoid hemorrhage. It was detected that gender, alcohol and tobacco use, blood group, the size and the number of aneurysm, the presence of intraventricular hemorrhage and Fisher grading were not the determinative factors in the patients. In patients who underwent surgery for subarachnoid hemorrhage, risk factors for postoperative hydrocephalus should be determined and the patients with these risk factors should be closely monitored.

Ascending aortic aneurysm repair and surgical ablation for atrial fibrillation

BackgroundAlthough surgical ablation of atrial fibrillation is commonly performed during concomitant coronary or valve surgery, it is still only performed in a fraction these cases when indicated, and less often in patients undergoing aneurysm surgery. We describe our experience in patients undergoing ascending aneurysm repair and concomitant atrial fibrillation ablation.MethodsFrom January 2004 until November 2011, 40 patients underwent ascending aneurysm repair and atrial fibrillation ablation at our institution and were retrospectively analyzed.ResultsAverage age was 67.6 years (43–85). Root replacement was performed in 23 (57.5 %) and arch replacement with circulatory arrest in 18 (45 %). At an average of 41.8 months, 81 % of patients were in sinus rhythm. Operative survival was 100 %, with 1 and 5 year survival of 97.5 and 93.1 %, respectively. Kaplan-Meier analysis revealed improved overall survival in patients with rhythm success (log-rank test p = 0.037).ConclusionsAortic aneurysm repair with concomitant atrial fibrillation ablation is safe and efficacious despite the requirement for an already extensive procedure with rhythm success rates similar to those quoted in the setting of other procedures. Successful restoration of sinus rhythm improves long term survival and should be considered in patients presenting with aortic aneurysm and atrial fibrillation.

Comparing routine versus selective use of intraoperative cerebral angiography in aneurysm surgery: a prospective study

IntroductionWhile the use of intraoperative angiography (IA) has been shown to be a useful adjunct in aneurysm surgery, its routine use remains controversial.ObjectiveWe wished to determine if IA is required...

A39 Session 11: Cardiovascular Disease Intervention: Afib cryo-ablation as a concomitant procedure to aneurysm repair

Since the development of cryo-energy for surgical ablation of atrial fibrillation, the procedure has become safer and more effective as concomitant to coronary or valve surgery. However, it is still only performed in a fraction these cases when indicated, and less often in patients undergoing aneurysm surgery. We describe our experience in patients undergoing ascending aneurysm repair and concomitant surgical cryoablative atrial fibrillation MAZE. From January 2004 until November 2011, 40 patients underwent ascending aneurysm repair and surgical cryo-ablation at our institution and were retrospectively analyzed. Average age was 67.6 years (43–85) and nine (23%) patients were female. Preoperative, intraoperative, and postoperative variables including complications, rhythm success, and survival were analyzed. Aortic root replacement was performed in 23 (57.5%) and arch replacement with circulatory arrest in 18 (45%). An average of 5 lesions were performed. Each was performed for 60 s. All lesions achieved temperatures of −120 °C. At an average of 41.8 months, 81% of patients were in sinus rhythm, and 63% were in sinus rhythm off antiarrhythmic medications. Operative survival was 100%, with actuarial one and five year survivals of 97.5% and 93.1%, respectively. Kaplan–Meier analysis revealed improved overall survival in patients with rhythm success (log-rank test p = 0.037). Aortic aneurysm repair with concomitant Cryo-ablative MAZE is safe and efficacious despite the requirement for an already extensive procedure. Excellent short and long term survival can be achieved as can rhythm success rates similar to those quoted in the setting of other procedures. Successful restoration of sinus rhythm improves long term survival and should be considered in patients presenting with aortic aneurysm and atrial fibrillation.

Managing Hypothermia in Cardiac Arrest and Rewarming

Many institutions are currently utilizing therapeutic hypothermia to target cardiac arrest as well as different types of brain injuries. Confounding issues including accidental hypothermia as well as the need to carefully rewarm patients with some types of physiological monitoring strategies are an area of active investigation and discussion. This particular session brought together experts in the field from cardiology, surgery, and trauma to discuss current strategies for managing hypothermia and temperature maintenance in various patients with different types of disorders. Dr. Eric Zoog, medical director of the Emergency Department, Mississippi Baptist Medical Center, provided an interesting summation of how he and his colleagues developed a successful hypothermia program in a community hospital. Several important points were made in terms of the processes, including convincing various services to help with this important program. Dr. Robert Silbergleit, Department of Emergency Medicine, University of Michigan Health System, discussed his experience in various clinical trials, including the use of hypothermia in cardiac arrest as well as patients undergoing aneurysm surgery. His experience emphasized the importance of introducing careful strategies to monitor brain function during cooling and rewarming phases. Dr. Josh Levine, Department of Neurology, University of Pennsylvania, discussed the use of hypothermia in various brain injury conditions. Most importantly, he and his colleagues have been investigating the importance of developing surrogate biomarkers that could aid in the assessment of the status of the brain. Most importantly, these biomarkers could be used to individualize treatments based on active processes. This session had a very interesting question-and-answer exchange, again emphasizing the interest in using therapeutic hypothermia and temperature management strategies during various emergency situations.

Intradural Clinoidectomy and Postoperative Headache in Patients Undergoing Aneurysm Surgery

The incidence of severe, chronic postoperative headache in patients undergoing elective surgery for unruptured aneurysms is unknown. In addition, no clear risk factors have been identified for the development of postoperative headache. To evaluate intradural drilling of the anterior clinoid process as a mechanism for the development of postoperative headache after open aneurysm repair. A retrospective review of 128 patients undergoing open surgical treatment for unruptured, proximal carotid aneurysms treated at the University of Texas Southwestern Medical Center between January 2004 and December 2007. Patients who required intradural drilling of the anterior clinoid process were compared with patients in whom additional drilling was not necessary. The presence of postoperative headache and the duration and severity were noted. In 28% of patients who underwent surgery with intradural clinoidectomy severe headache developed vs 7% of patients without clinoidectomy. This result was statistically significant (P < .05, Fisher exact test). Intradural drilling of the anterior clinoid process was associated with an increased incidence of postoperative headache compared with no resection. This implicates either the dural manipulation necessary to expose the clinoid and optic strut or the introduction of bone dust into the subarachnoid space as potential risk factors for postoperative headache.

Efficacy of aneurysmectomy in patients with severe left ventricular dysfunction: favorable short- and long-term results in ischemic cardiomyopathy

INTRODUCTION:The purpose of this study was to (1) identify the functional results after aneurysm surgery in patients with ischemic cardiomyopathy and (2) identify predictors of favorable outcomes.METHODS AND MATERIAL:Patients (n = 169) with angiographic left ventricular ejection fraction of 22±5% underwent aneurysm surgery and were prospectively followed for three years. Prior to surgery, 40% and 60% of the patients were in congestive heart failure NYHA class I/II and III/IV, respectively. Concomitant revascularization was performed on 95% of the patients.RESULTS:Cumulative in‐hospital and 36‐month mortalities were 7% and 15%, respectively. These respective rates varied according to preoperative parameters: CHF class I‐II, 4% and 13%; CHF class III‐IV, 8% and 16%; LVEF<20%, 12% and 26%; LVEF 21‐30%, 2% and 6%; gated LVEF exercise/rest >5%, <1% and 4%; and gated LVEF exercise/rest ≤5%, 17% and 38%. Higher LVEF ex/rest ratio (p = 0.01), male sex (p = 0.05), and a higher number of grafts (p = 0.01) were predictive of improvement in CHF class at follow‐up based on the results of a multivariate analysis. After three years of follow‐up, 84% of the patients were in class I/II, LVEF was 45±7%, and gated LVEF ex/rest ratio was 13% higher (p<0.01) compared to the beginning of the study.CONCLUSIONS:These data suggest that aneurysmectomy among patients with severe LV dysfunction result in short‐ and long‐term favorable functional outcome and survival. Selection of appropriate surgical candidates may substantially improve survival rates among these patients.

Independent Associations Between Electrocardiographic Abnormalities and Outcomes in Patients With Aneurysmal Subarachnoid Hemorrhage

Electrocardiographic abnormalities are common after subarachnoid hemorrhage, but their significance remains uncertain. The aim of this study was to determine whether any specific electrocardiographic abnormalities are independently associated with adverse neurological outcomes. This was a substudy of the Intraoperative Hypothermia Aneurysm Surgery Trial, which was designed to determine whether intraoperative hypothermia would improve neurological outcome in patients with subarachnoid hemorrhage undergoing aneurysm surgery. The outcome was the 3-month Glasgow Outcome Score treated as both a categorical measure (Glasgow Outcome Score 1 [good outcome] to 5 [death]) and dichotomously (mortality/Glasgow Outcome Score 5 versus Glasgow Outcome Score 1 to 4). The predictor variables were preoperative electrocardiographic characteristics, including heart rate, corrected QT interval, and ST- and T-wave abnormalities. Univariate logistic regression was performed to screen for significant electrocardiographic variables, which were then tested for associations with the outcome by multivariate logistic regression adjusting for clinical covariates. The study included 588 patients, of whom 31 (5%) died. There was a significant, nonlinear association between heart rate and mortality such that lowest quartile (<or=60 beats/min; OR, 6.5; P=0.027) and highest quartile (>80 beats/min; OR, 8.8; P=0.006) were associated with higher risk. There was also a significant association between nonspecific ST- and T-wave abnormalities and mortality (OR, 3.1; P=0.031). Bradycardia, relative tachycardia, and nonspecific ST- and T-wave abnormalities are strongly and independently associated with 3-month mortality after subarachnoid hemorrhage. Further research should be performed to determine whether there is a causal relationship between cardiac dysfunction and neurological outcome after subarachnoid hemorrhage.

Abnormal Responses of the Human Cerebral Microcirculation to Papaverin During Aneurysm Surgery

The role of the cerebral microcirculation in delayed ischemia after subarachnoid hemorrhage remains obscure. To test the hypothesis that cerebral arterioles have a reduced capacity to dilate after subarachnoid hemorrhage, we studied the microvascular responses to papaverine (PPV) in patients undergoing aneurysm surgery. Method- In 14 patients undergoing aneurysm surgery, the diameter changes of cortical microvessels after topical application of PPV were observed using orthogonal polarizing spectral imaging. In control subjects, neither arterioles nor venules showed diameter changes in response to topical PPV. In patients operated <48 hours after subarachnoid hemorrhage, PPV resulted in vasodilatation of arterioles with 45+/-41% increase in arteriolar diameter (P=0.012). In 2 of these patients, arteriolar diameter returned below baseline value. In patients undergoing late aneurysm clipping, the diameter increase of the arterioles after PPV was 25+/-24% (not significant). In 2 patients of this group, no vasodilatation but focal arteriolar narrowing occurred. In patients with subarachnoid hemorrhage, unpredictable response patterns to PPV were observed with "rebound" vasoconstriction suggesting increased contractility of the microcirculation. Yet, diminished vasodilatory capacity of the cerebral microcirculation after subarachnoid hemorrhage was not confirmed by this study.

Confirmation of blood flow in perforating arteries using fluorescein cerebral angiography during aneurysm surgery

The authors performed fluorescein cerebral angiography in patients after aneurysm clip placement to confirm the patency of the parent artery, perforating artery, and other arteries around the aneurysm. Twenty-three patients who underwent aneurysm surgery were studied. Aneurysms were located in the internal carotid artery in 12 patients, middle cerebral artery in six, anterior cerebral artery in three, basilar artery bifurcation in one, and junction of the vertebral artery (VA) and posterior inferior cerebellar artery in one. After aneurysm clip placement, the target arteries were illuminated using a beam from a blue light-emitting diode atop a 7-mm diameter pencil-type probe. In all patients, after intravenous administration of 5 ml of 10% fluorescein sodium, fluorescence in the vessels was clearly observed through a microscope and recorded on videotape. The excellent image quality and spatial resolution of the fluorescein angiography procedure facilitated intraoperative real-time assessment of the patency of the perforating arteries and branches near the aneurysm, including: 12 posterior communicating arteries; 12 anterior choroidal arteries; four lenticulostriate arteries; three recurrent arteries of Heubner; three hypothalamic arteries; one ophthalmic artery; one perforating artery arising from the VA; and one posterior thalamoperforating artery. All 23 patients experienced an uneventful postoperative course without clinical symptoms of perforating artery occlusion. Because the fluorescein angiography procedure described here allows intraoperative confirmation of the patency of perforating arteries located deep inside the surgical field, it can be practically used for preventing unexpected cerebral infarction during aneurysm surgery.

Direct observation of the human cerebral microcirculation during aneurysm surgery reveals increased arteriolar contractility.

The effects of aneurysmal subarachnoid hemorrhage on morphology and function of the cerebral microcirculation are poorly defined, partly due to the lack of suitable techniques to visualize the microvessels in vivo. We used orthogonal polarization spectral (OPS) imaging on the brain cortex during aneurysm surgery to directly observe the small cortical blood vessels and quantify their responses to hypocapnia. In 16 patients undergoing aneurysm surgery, the diameter changes of small cortical vessels (15 to 180 microm) were observed using OPS imaging. Ten patients were operated on early (within 48 hours after bleeding) and 6 underwent late surgery. Immediately after dura opening, the response to hyperventilation of arterioles and venules was observed with OPS imaging under sevoflurane anesthesia. In patients operated on early, layers of subarachnoid blood were clearly visible. In this group, hyperventilation resulted in a 39+/-15% decrease in arteriolar diameter with a "bead-string" constriction pattern occurring in 60% of patients. In late surgery and in controls, no subarachnoid blood was seen. The arteriolar diameter decrease with hyperventilation was 17+/-20% in patients undergoing late surgery and 7+/-7% in controls. Venules were not affected by hyperventilation in any of the groups studied. OPS imaging allows direct in vivo observation of the cerebral microcirculation enabling us, for the first time, to visually observe and quantify microvascular reactivity in the human brain. The present study demonstrates increased contractile responses of the cerebral arterioles in the presence of subarachnoid blood, suggesting increased microvascular tonus with possibly greater susceptibility to ischemia.

Blood transfusion during aneurysm surgery.

Increasing costs and concerns about blood supply safety have led to a reevaluation of blood transfusion practices. This study was undertaken to examine blood use during aneurysm surgery. We performed a retrospective analysis of hospital records including operative, anesthetic, and nursing notes, computed tomographic scans, and four-vessel angiographic films of 547 patients undergoing surgery for ruptured and unruptured cerebral aneurysms at Harborview Medical Center in Seattle. During the review period, the transfusion threshold was not altered. A total of 134 patients (24.5%) received an intraoperative blood transfusion (median number of units, 2; range, 1-17). Preoperative factors associated with intraoperative blood use included older patient age (P < 0.001), lower hematocrit level on admission (P = 0.007), ruptured rather than unruptured aneurysm (P = 0.004), severe intraventricular hemorrhage (P = 0.03), and larger aneurysm size (P = 0.004). Factors not associated with intraoperative blood transfusion included past medical history (including cardiac or pulmonary disease), admission clinical grade after aneurysm rupture, findings such as hydrocephalus on computed tomographic scanning, and aneurysm location and aneurysm neck-to-fundus ratio. Also associated with blood transfusion during surgery were intraoperative aneurysm rupture (P < 0.0001), intracerebral hematoma evacuation (P = 0.02), and obliteration of multiple aneurysms (P = 0.002). Among patients who received an intraoperative transfusion, those who experienced an aneurysm rupture required an average of 3.6 +/- 0.35 units, whereas patients who did not have a rupture required 1.9 +/- 0.12 units (P = 0.001). Postoperatively, a total of 244 patients (44.6%), including 77 who received blood intraoperatively, required a blood transfusion (median number of units, 2; range, 1-31). Postoperative blood transfusion was associated with the treatment of patients with subarachnoid hemorrhage (P < 0.0001), particularly among poor-grade patients who developed medical complications. Blood transfusion can be expected in one in five patients undergoing aneurysm surgery. Reducing intraoperative rupture may reduce the need for blood products.

Results of surgical treatment of intrasylvian hematomas due to ruptured intracranial aneurysms

In this retrospective study, the surgical outcome of patients with intrasylvian hematomas due to rupture of intracranial aneurysms was analyzed. The authors studied ten patients who underwent aneurysm surgery and evacuation of the hematoma within 12 h of the onset of bleeding. All patients had an intrasylvian hematoma classified with computerized tomography and all patients underwent pre-operative angiography. In all patients, the origin of bleeding was a middle cerebral artery aneurysm, with the exception of one patient whose bleeding originated from a posterior communicating artery aneurysm. Three patients achieved good recovery without any significant neurological deficit and four achieved good recovery with moderate disabilities. One patient died due to pneumonia and two were in a vegetative state. Notably, three patients who were comatose (Hunt and Hess Grade V) at the time of presentation achieved good recovery following surgery. In this study, neurological status at presentation did not predict the outcome. The only significant prognostic factor in those patients who had intrasylvian hematoma was early surgery within 12 h of the bleeding. We suggest that early surgical treatment be performed in patients with intrasylvian hematoma, regardless of the neurological findings and grade on admission. Pre-operative angiography seems to be essential in identifying the source of bleeding.

Request of psychiatric aid in ischemic heart disease and major depressive disorder

We analyzed consecutive subarachnoid hemorrhage (SAH) cases in patients older than 70 years of age who underwent aneurysm surgery. We report the influence of early ambulation on outcome in advanced-age SAH.From 2005 through 2010, 71 aneurysmal SAH cases whose Hunt-Hess grades ranged from 1 to 3 were included. All cases underwent clip ligation or coil embolization. Male to female ratio was 8/63; median age was 76 years (range, 70–87). We routinely have patients become ambulatory the day after surgery. The ambulation date was used to determine four groupings: 0–5 days, 6–10 days, 11–15 days, and 16 days and longer. We analyzed the relationship between ambulation date and the Glasgow Outcome Scale (GOS) or dementia at 30 days after the SAH. Favorable outcome was defined as good recovery and moderate disability according to the GOS. Dementia was screened by use of the revised-Hasegawa dementia scale. The chi-square test was used and a P < 0.05 was considered statistically significant.Mean days to ambulation was 10.7 ± 9.3 SD days. Forty-eight cases (66%) achieved favorable outcome, and 27 cases (38%) reached a nondemential state. Early ambulation positively correlated with favorable GOS and postoperative nondemential state.Elderly SAH patients with good Hunt-Hess grades should have a clip ligation or endovascular coiling. Early ambulation produces favorable outcome and a nondemential state in elderly SAH patients.

Influence of smoking, hypertension, and sex on the phenotypic expression of familial intracranial aneurysms in siblings.

To investigate the effects of smoking, hypertension, and sex on the phenotypic expression of familial intracranial aneurysms (FIAs). We retrospectively reviewed the case records of 806 consecutive patients undergoing aneurysm surgery at our institution (1986-1995) and discovered 24 families with at least two affected siblings. Prevalence rates for the smoking, hypertension, and sex risk factors in these nuclear families were compared with those of patients with sporadic intracranial aneurysms (SIAs) and population-based control patients. Affected family members with FIAs exhibited prevalence rates of smoking and hypertension (74% and 43%, respectively) that tended to be higher than those of population-based control patients (52% [P < 0.005] and 36% [P = not significant (NS)], respectively) and comparable to those of patients with SIAs (64% [P = NS] and 40% [P = NS], respectively). A positive association existed between FIA formation and female sex but was somewhat less strong than that observed in the SIAs (59% FIAs, 71% SIAs, 50% control patients). In addition, the prevalence rates of smoking, hypertension, and female sex were higher in affected family members with FIAs than in their unaffected siblings (58% [P < 0.05], 28% [P = 0.06], and 39% [P < 0.05], respectively). Individuals in families with expressed FIAs who had high aneurysmal penetrance had a greater tendency to be smokers, hypertensive, and female (74%, 59%, and 55%, respectively) than did their low-penetrance counterparts (61% [P = 0.1], 27% [P < 0.05], and 45% [P = NS], respectively). Together these data suggest that hypertension, smoking, and female sex increase the likelihood that a member of a family with an expressed FIA will have an aneurysm. These observations may prove helpful in guiding the use of screening studies and encouraging education about the potential risks of continued tobacco use and untreated hypertension in this patient cohort.

The monitoring of somatosensory evoked potentials and neurologic complications in aneurysm surgery

Somatosensory evoked potential (SSEP) changes during cerebral aneurysm surgery and their relationship to postoperative neurologic complications have been studied on many occasions. However, it is still a matter of debate whether SSEP monitoring is really helpful in detecting or preventing neurologic complications. We studied 87 patients undergoing aneurysm surgery of the anterior cerebral circulation and SSEPs were monitored in 60 of these patients. All patients were grade 2 by the subarachnoid hemorrhage (SAH) grading system. Median nerve SSEP was monitored for middle cerebral or internal carotid artery aneurysms and posterior tibial nerve SSEP for anterior cerebral artery aneurysms. A decrease in the cortical amplitude of more than 50%, compared with control, was considered significant and interventions were then taken to reverse the SSEP. The pre- and postoperative neurologic deficits of each patient were evaluated immediately before and after surgery. No significant difference was found in the incidence of postoperative neurologic complications in the SSEP monitored (15% [9/60]) and unmonitored patients (22% [6/27]). In the SSEP monitored patients, the amplitudes of SSEPs decreased significantly in 14 patients and 4 of these showed neurologic complications. However, SSEP amplitudes were not significantly changed in 46 patients, and 5 of these showed neurologic complications. Significant changes in the amplitude of SSEP might represent neuronal injury, but the absence of change in the SSEP cannot guarantee patient safety. Our results suggest that SSEP monitoring may be useful for detecting the danger of neuronal injury, but that it does not reduce the incidence of neurologic complications in aneurysm surgery.

Serum total antioxidant status during vascular surgery.

Reactive oxygen free radical species (ROS) are highly reactive and potentially damaging transient chemical species formed as an unwanted by-product of normal aerobic metabolism in all tissues. Cells are protected from ROS induced damage by a variety of endogenous ROS scavenging enzymes and chemical compounds. Tissue damage resulting from an imbalance between ROS generating and scavenging systems has been implicated in the pathogenesis of a variety of disorders; in particular,it has been suggested that ischaemic reperfusion of the lower torso in patients undergoing surgery for abdominal aortic aneurysm (AAA) repair results in generation of ROS, with subsequent damage to various tissues. Because of their high reactivity and short half lives, direct monitoring of ROS is technically very difficult. Previous research has suggested that measurement of circulatory ( s e d p l a s m a ) total antioxidant status is a useful measure of ROS activity in vivo, since significant decreases in this parameter have been demonstrated in patients undergoing aortic aneurysm repair [l]. The objective of the present investigation was to confirm this finding, with the aim of developing antioxidant supplementation therapy in patients undergoing aneurysm surgery. Blood samples from four patients undergoing open AAA repair were taken via a femoral vein line before, during and after clamping of the aorta and iliac arteries (mean clamp time lhr). Serum samples were stored at -8OOC prior to analysis of total antioxidant levels, which was determined via the method of RiceEvans and Miller [2], based on the attenuation of the generation of the ABTS (2,2 '-azino-bis 3-ethylbenzthiazoline-6-sulphonic acid) radical by a metmyoglobin catalyst / hydrogen peroxide system (quantitated colourimetrically). Changes in the total antioxidant level (mM Trolox equivalent) in sequential serum samples from four cases undergoing surgery, as above, are shown in Table 1 (mean f SD). The significance of differences for values obtained during or after clamping, relative to p5-clamping values, was assessed via students' t-test. It is apparent from the data presented that there is no significant change in serum antioxidant levels during or after aortic clamping (compared to pre clamping levels), in contrast to previously reported findings [l]. In an attempt to resolve these conflicting data, a further experiment was carried out to determine changes in total antioxidant levels in normal sera following exposure to ROS, generated under controlled experimental conditions in vitro via

Development and prevention of frozen shoulder after acute aneurysm surgery

We conducted a study on periarthritis humeroscapularis or "frozen shoulder," a postoperative complication of aneurysm surgery. The purpose of this study was to seek the cause of this complication and the methods of preventing it in patients who undergo aneurysm surgery. The diagnosis of frozen shoulder was based on the clinical presence of shoulder pain and difficulty in raising arms that developed within 3 months of surgery. Sixty-four patients who underwent aneurysm surgery with no motor deficit were examined and classified into three groups: (1) early surgery (29 patients in the acute stage after subarachnoid hemorrhage); (2) delayed surgery (19 patients in the chronic stage); and (3) elective surgery (16 patients with unruptured aneurysms). The incidence of frozen shoulder was 41% in the early surgery group, 16% in the delayed surgery group, and 13% in the elective surgery group. The highest incidence of frozen shoulder was found to occur in the early surgery group and was attributed to the immobility of their upper extremities during postoperative treatment. Since patients who undergo surgery in the acute stage are often delirious and confused for several days after surgery, their arms are tied down by their sides in order to prevent them from inadvertently removing catheters such as the one for ventricular drainage. It seems that this manner of immobilizing the patient's arms is the cause of the development of frozen shoulder: Our study showed that if each arm was passively raised by turns above the patient's shoulder, the patient was able to maintain the range of motion of the upper arms and was less likely to develop frozen shoulder. Inactivity of the shoulder joints due to immobilizing the upper extremities of patients after acute aneurysm surgery seemed to cause the development of frozen shoulder. The incidence of this complication was greatly reduced by keeping the patient's upper arms raised alternately to maintain their range of motion after acute aneurysm surgery.