Incidence of symptomatic hemorrhage after stereotactic electrode placement

OBJECT: Intracranial hemorrhage (ICH) is the most significant complication associated with the placement of stereotactic intracerebral electrodes. Previous reports have suggested that hypertension and the use of microelectrode recording (MER) are risk factors for cerebral hemorrhage. The authors evaluated the incidence of symptomatic ICH in a large cohort of patients with various diseases treated with stereotactic electrode placement. They examined the effect of comorbidities on the risk of ICH and independently assessed the risks associated with age, sex, use of MER, diagnosis, target location, hypertension, and previous use of anticoagulant medications. The authors also evaluated the effect of hemorrhage on length of hospital stay and discharge disposition. METHODS: Between 1991 and 2005, 567 electrodes were placed by two neurosurgeons during 337 procedures in 259 patients. Deep brain stimulation (DBS) was performed in 167 procedures, radiofrequency lesioning (RFL) of subcortical structures in 74, and depth electrodes were used in 96 procedures in patients with epilepsy. Electrodes were grouped according to target, patient diagnosis, use of MER, patient history of hypertension, and patient prior use of anticoagulant medication (stopped 10 days before surgery). The Charlson Comorbidity Index (CCI) was used to evaluate the effect of comorbidities. The CCI score, patient age, length of hospital stay, and discharge status were continuous variables. Symptomatic hemorrhages were grouped as transient or leading to permanent neurological deficits. RESULTS: The risk of hemorrhage leading to permanent neurological deficits in this study was 0.7%, and the risk of symptomatic hemorrhage was 1.2%. A patient history of hypertension was the most significant factor associated with hemorrhage (p = 0.007). Older age, male sex, and a diagnosis of Parkinson disease (PD) were also significantly associated with hemorrhage (p = 0.01, 0.04, 0.007, respectively). High CCI scores, specific target locations, and prior use of anticoagulant therapy were not associated with an increased risk of hemorrhage. The use of MER was not found to be correlated with an increased hemorrhage rate (p = 0.34); however, the number of hemorrhages in the patients who underwent DBS was insufficient to draw definitive conclusions. The mean length of stay for the DBS, RFL, and depth electrode patient groups was 2.9, 2.6, and 11.0 days, respectively. For patients who received DBS and RFL, the mean duration of hospitalization in cases of symptomatic hemorrhage was 8.2 days compared with 2.7 days in those without hemorrhaging (p < 0.0001). Three of the seven patients with symptomatic hemorrhages were discharged home. CONCLUSIONS: The placement of stereotactic electrodes is generally safe, with a symptomatic hemorrhage rate of 1.2%, and a 0.7% rate of permanent neurological deficit. Consistent with prior reports, this study confirms that hypertension is a significant risk factor for hemorrhage. Age, male sex, and diagnosis of PD were also significant risk factors. Patients with symptomatic hemorrhage had longer hospital stays and were less likely to be discharged home.     

Early postoperative MRI in detecting hematoma and dural compression after lumbar spinal decompression: prospective study of asymptomatic patients in comparison to patients requiring surgical revision

Early postoperative MRI after spinal surgery is difficult to interpret because of confounding postoperative mass effects and frequent occurrence of epidural hematomas. Purpose of this prospective study is to evaluate prevalence, extent and significance of hematoma in the first postoperative week in asymptomatic patients after decompression for lumbar stenosis and to determine the degree of clinically significant dura compression by comparing with the patients with postoperative symptoms. MRI was performed in 30 asymptomatic patients (47 levels) in the first week after lumbar spine decompression for degenerative stenosis. Eleven patients requiring surgical revision (16 levels) for symptomatic early postoperative hematoma were used for comparison. In both groups the cross-sectional area of the maximum dural compression (bony stenosis and dural sac expansion) was measured preoperatively and postoperatively by an experienced radiologist. Epidural hematoma was seen in 42.5% in asymptomatic patients (20/47 levels). The median area of postoperative hematoma at the operated level was 176 mm² in asymptomatic patients and 365 mm² in symptomatic patients. The median cross-sectional area of the dural sac at the operated level was 128.5 and 0 mm² in asymptomatic and symptomatic patients, respectively, at the site of maximal compression. In the symptomatic group 75% of the patients had a maximal postoperative dural sac area of 58.5 mm² or less, whereas in the asymptomatic group 75% of patients with epidural hematoma had an area of 75 mm² or more. The size of hematoma and the degree of dural sac compression were significantly larger in patients with symptoms needing surgical revision. Dural sac area of less than 75 mm² in early postoperative MRI was found to be the threshold for clinical significance.     

Long-term hardware-related complications of deep brain stimulation

OBJECTIVE: To determine the incidence of long-term hardware-related complications of deep brain stimulation (DBS). METHODS: The study design is a retrospective chart review of a single-surgeon, single-institution experience with DBS in 84 consecutive cases from 1993 to 1999. Only patients with a minimum follow-up of 1 year were considered. Five patients were excluded because trial stimulation failed to achieve pain relief (n = 4) or because the procedure was aborted owing to hemorrhage (n = 1). Seventy-nine patients received 124 permanent DBS electrode implants. RESULTS: The mean follow-up period was 33 months, and the cumulative follow-up time was 217 patient-years or 310 electrode-years. Overall, 20 patients (25.3%) had 26 hardware-related complications involving 23 (18.5%) of the electrodes. There were 4 lead fractures, 4 lead migrations, 3 short or open circuits, 12 erosions and/or infections, 2 foreign body reactions, and one cerebrospinal fluid leak. The hardware-related complication rate per electrode-year was 8.4%. The most common complications were related to the electrode connectors. A significant finding was a high number of complications involving erosions or infections, which occurred in 7 of 12 instances as a late complication (beyond 12 mo). CONCLUSION: Long-term follow-up reveals that hardware-related complications occur in a significant number of patients. Factors that lead to such complications must be identified and addressed to maximize the important benefits of DBS therapy.     

Hemorrhagic complication of stereotactic surgery in patients with movement disorders

OBJECT: Small, asymptomatic hemorrhages are easier to detect during stereotactic surgery when magnetic resonance (MR) imaging is used for targeting rather than when traditional approaches, such as ventriculography, are performed with contrast material. In the present study the authors examined the actual incidence of intraoperative hemorrhages in patients with movement disorders who had undergone MR imaging-targeted surgery, microelectrode recording (MER)-guided implantation of deep brain stimulation (DBS) electrodes, or radiofrequency-induced coagulation surgery performed. METHODS: Ninety-six consecutive patients underwent a total of 116 stereotactic operations for movement disorders (57 operations for radiofrequency-induced coagulation and 59 for DBS electrode implantation) between January 1998 and November 2002. The authors investigated the correlation between hemorrhages and other factors including the location of the hemorrhage and the type of surgery performed. Postoperative computerized tomography scans demonstrated the occurrence of intraoperative hemorrhages at 12 locations during 11 procedures (9.5% of all procedures). Nine hemorrhages occurred during 57 coagulation operations (15.8%). Within this group, the frequency of hemorrhages was highest during thalamotomy (five [21.7%] of 23 procedures) and lower during pallidotomy (four [11.8%] of 34 procedures). In contrast, only two intraventricular hemorrhages developed during 59 operations in which DBS electrodes were implanted (3.4%). In no case was hemorrhage detected in the main DBS target, that is, the subthalamic nucleus. CONCLUSIONS: When small, asymptomatic hemorrhages were included in the estimation, the actual rate of hemorrhage was higher than that previously reported. Judging from the incidence of hemorrhage during coagulation and DBS surgeries, the authors suggest that the heat induced by coagulation may play a larger role than microelectrode penetration in the development of hemorrhage.     

Multiple target aspiration technique for subacute stereotactic aspiration of hematomas within the basal ganglia

BACKGROUND: Stereotactic surgery for deep-seated intracerebral hematomas as a minimally invasive procedure has gained wide acceptance, but debate continues to be controversial concerning the issue of how to aspirate a sufficient proportion of the hematoma with minimized risk for the patient. The objective of this paper is to present a modified stereotactic aspiration technique which complies saliently with both demands. METHODS: The multiple target aspiration technique was used in a series of 64 consecutive patients with spontaneous hematomas within the basal ganglia. The results obtained with this technique were evaluated with particular regard to degree of aspiration and rate of recurrent hemorrhage and were compared with results achieved with stereotactic techniques utilizing physical fragmentation or chemical lysis of the clots. RESULTS: Using this technique, it was feasible in one single surgical procedure to aspirate more than 80% of the hematoma volume in 73.4% of the patients. Mean degree of aspiration was 88.8%, and rebleeding occurred only once (1.6%). These results compare favorably with those achieved with application of intricate stereotactic techniques. CONCLUSION: The multiple target aspiration technique performed in the subacute stage is a rapid and simple method for stereotactic removal of deep-seated hematomas and combines a high success rate with very low risk of recurrent hemorrhage.     

Late Intracapsular Seroma in Subfascial Buttock Augmentation: A Case Report

Late intracapsular seroma and hematoma have been described frequently as a complication of breast augmentation surgery. However, there are few reports of late intracapsular seroma in buttock augmentation. Textured and polyurethane implants have been used for subfascial enlargement of the buttocks. In this article, the authors report a large late intracapsular bilateral seroma caused by a retrofascial polyurethane-covered implant used for buttock augmentation: 1,200 ml on one side and 300 ml on the other. This patient’s intracapsular seroma was of sudden onset 2 years and 6 months after surgery, and apparently had no relation to any trauma, use of medication, or physical exercise. Local tissues, including the gluteal fascia, were distended such that the implant was replaced inside the muscle and there was no relapse of the seroma. Late intracapsular hematomas or seromas from implants for buttock and breast augmentation may have the same etiology, and textured implants seem to be involved. All the reports on the matter are associated with textured implants. Any late seroma or hematoma caused by a smooth implant is related to an additional factor that may be considered as the etiologic agent. Further studies aimed at a large-scale assessment of the cause and actual incidence of late seromas and hematomas from textured implants are required.     

Sulcal and ventricular trajectories in stereotactic surgery

OBJECT: The authors analyzed deep brain stimulation electrode trajectories on MR images to identify risks of cerebrovascular complications associated with the number of electrode insertions, traversal of a sulcus, and penetration of the ventricle. METHODS: Pre- and postoperative MR volumes were fused to determine the proximity of electrodes to a sulcus or ventricle and whether there were cortical, subcortical, or intraventricular complications. Complications were further classified as hemorrhagic or nonhemorrhagic and symptomatic or asymptomatic. The authors examined 258 electrode implantation for deep brain stimulation. There were 4 symptomatic events (1.6% incidence): 3 hemorrhagic and 1 nonhemorrhagic, all within the cortex. Asymptomatic events included cortical hemorrhage in 1 patient, nonhemorrhagic cortical changes in 6, pallidal hemorrhage in 1, thalamic infarction in 1, and intraventricular hemorrhage (IVH) in 5 patients. RESULTS: Proximity to a sulcus was a significant risk factor for hemorrhagic and nonhemorrhagic cortical complications (p = 0.001). There was a complication rate of 10.1% within the trajectories penetrating or adjacent to a sulcus, and a 0.7% rate with trajectories clearly positioned within the gyrus. Asymptomatic IVH was observed in 5% of ventricular penetrations. A history of hypertension was a risk factor for cortical hemorrhage (p = 0.019), but not for cortical ischemic/edematous events (p = 0.605). The number of electrode penetrations did not differ between patients with and without complications (p = 0.868), and the sequence of electrode insertions was not a risk factor in bilateral surgeries. CONCLUSIONS: Symptomatic cortical complications occur when electrodes traverse close to a sulcus. Asymptomatic IVH occurs infrequently with ventricular penetration. Despite intraoperative efforts to avoid cortical sulci, a higher than expected incidence of electrode proximity to the sulci was identified on careful postoperative trajectory analysis. This finding emphasizes the importance of assiduously planning trajectories and reviewing cases with thorough MR analysis.     

Acute symptomatic hematoma with defined etiology seven years after breast reconstruction: A case report and literature review

Augmentation mammaplasty with implants can be complicated by hematoma formation. The majority of hematomas occur in the immediate postoperative period. There are, however, some reports of hematomas with a delayed presentation. These hematomas in the late postoperative period are rare, and many of these cases do not have a definitive mechanism of injury or develop symptoms immediately after the triggering event. A case of late capsular hematoma seven years after breast reconstruction with a saline implant following mastectomy is presented. In contrast to the majority of published cases, the patient presented with both a known and traceable cause of her bleed and with symptoms that developed immediately after the initial event. Furthermore, the mechanism of her injury was consistent with a bleeding capsular tear that was observed intraoperatively. The present case emphasizes the importance of thorough evaluation and management of patients with a history of breast reconstruction.     

The significance of thrombocytopenia in the development of postoperative intracranial hematoma

A group of 35 patients undergoing intracranial surgery who exhibited perioperative thrombocytopenia (platelet count less than 150,000/microliters) was studied retrospectively. Of the 35 patients, 14 (40%) developed postoperative intracranial hematomas requiring reoperation and seven (20%) died within 2 weeks after the operation. Analysis revealed that a perioperative platelet count below 100,000/microliters in a patient who failed to respond to platelet transfusions was associated with a higher risk of postoperative hematoma formation. All six patients with this profile developed postoperative hematomas. If the platelet count rose promptly from below 100,000/microliters to a normal level after platelet transfusions, the incidence of hematoma formation decreased dramatically. None of the three patients with this response developed postoperative hematoma. In patients in whom an acute drop in platelet count from the normal range to between 100,000 and 124,000/microliters occurred in the immediate perioperative period, there was a significantly higher change of hematoma formation; this finding has not hitherto been described. Of the 14 patients with this clinical course, eight developed postoperative hematoma after craniotomy for tumors and vascular lesions. This latter observation was substantiated by the fact that thrombocytopenic patients with postoperative hematomas had a greater reduction in platelet count than thrombocytopenic patients with no postoperative hematomas (p = 0.0004).     

Incidence of silicone breast implant rupture

HYPOTHESIS: The incidence of silicone breast implant rupture varies with implantation time and type of implant. OBJECTIVE: To measure the incidence of implant rupture by repeated magnetic resonance imaging (MRI) among women with silicone breast implants. DESIGN, SETTING, AND PARTICIPANTS: In 1999, 271 women who had received breast implants at least 3 years before, and who were randomly chosen from a larger cohort of women with cosmetic breast implants, underwent a baseline MRI. A second MRI was performed in 2001; 317 silicone implants (in 186 women) that were intact at the baseline MRI (n = 280) or were intact at baseline but removed before the second MRI (n = 37) were included in the rupture incidence analyses. MAIN OUTCOME MEASURES: Implants were diagnosed with definite or possible rupture. Crude and implant age-adjusted incidence rates were calculated, and implant survival was estimated based on the observed rupture rates. RESULTS: We found 33 definite ruptures (10%) and 23 possible ruptures (7%) during the 2-year period. The overall rupture incidence rate for definite ruptures was 5.3 ruptures/100 implants per year (95% confidence interval, 4.0-7.0). The rupture rate increased significantly with increasing implant age. Double-lumen implants were associated with substantially lower rupture risk than single-lumen implants. For modern implants intact 3 years after implantation, we estimated rupture-free survival of 98% at 5 years and 83% to 85% at 10 years. CONCLUSIONS: The risk of implant rupture increases with implant age. A minimum of 15% of modern implants can be expected to rupture between the third and tenth year after implantation.     

Multi-institutional outcome study on the efficacy of closed-suction drainage of the scrotum in three-piece inflatable penile prosthesis surgery

Infection is a devastating complication of penile prosthesis surgery that occurs in approximately 2-5% of all primary inflatable penile primary implants in most series. Prevention of hematoma and swelling with closed-suction drains has been shown not to increase infection rate and yield an earlier recovery time. Despite the intuitive advantages of short-term closed-suction drainage in reducing the incidence of postoperative scrotal swelling and associated adverse effects, many urologists are reluctant to drain the scrotum because of a theoretical risk of introducing an infection. In conclusion, this study was undertaken to evaluate the incidence of infection in three-piece penile prosthesis surgery with scrotal closed-suction drainage. A retrospective review of 425 consecutive primary three-piece penile prosthesis implantations was performed at three institutions in New Jersey, Ohio, and Arkansas from 1998 to 2002. Following the prosthesis insertion, 10 French Round Blake (Johnson & Johnson) or, in a few cases, 10 French Jackson Pratt, closed-suction drains were placed in each patient for less than 24 h. All subjects received standard perioperative antibiotic coverage. Average age at implant was 62 y (range 24-92 y). Operative time (incision to skin closure) was less than 60 min in the vast majority of cases. There were a total of 14 (3.3%) infections and three hematomas (0.7%) during an average 18-month follow-up period. In conclusion, this investigation revealed that closed-suction drainage of the scrotum for approximately 12-24 h following three-piece inflatable penile prosthesis surgery does not result in increased infection rate and is associated with a very low incidence of postoperative hematoma formation, swelling, and ecchymosis.     

Bleeding cerebral neoplasms with symptomatic hematoma

AIM: This article discusses the role of intracranial tumors in the etiology of spontaneous intracerebral hematomas, compared to other causes such as hypertension, aneurysm, arteriovenous malformation (AVM) or cavernoma. An analysis of cerebral tumors, with a particular oncological emphasis on intrinsic bleeding during growth and resulting in symptomatic hematoma, is presented. METHODS: We analyzed 110 cases of intracranial tumor with symptomatic bleeding, accounting for 1.5% of 7373 intracranial neoplasms and 4.4% of 2514 intracerebral hematomas, surgically treated at the Department of Neurosurgery in Verona, from 1968 to 2000. The bleeding tumors comprised 36 (33%) glioblastomas, 23 (21%) metastases, 14 (13%) anaplastic gliomas, 13 (12%) low-grade gliomas, 13 (12%) meningiomas, 5 (5%) adenomas, 2 (2%) hemangioblastomas, 2 (2%) melanomas, 1 (1%) neuroblastoma and 1 (1%) pinealoblastoma. RESULTS: Analysis of the data of the 110 cases of tumors with symptomatic hematoma showed that there was a statistically significant correlation between the incidence of bleeding and histological groups according to the World Health Organization classification. A clinical study of these cases indicates that hematoma onset is more frequent in anaplastic gliomas (93%) and meningiomas (62%) than in other pathologies (p=0.008); meningiomas are prevalent on the left side (92%) (p=0.000); favorable bleeding factors correlate with meningioma (62%), (p=0.009). The postoperative short-term results following hematoma evacuation and tumor removal were significantly influenced only by patient age (p=0.000) and preoperative clinical condition (p=0.000). CONCLUSION: The analysis of our study population shows that the tumoral etiology of intracerebral hematomas is by no means negligible, accounting for 4.4% of 2514 hematomas operated on, and emphasizes the fact that not all bleeding neoplasms are malignant. Out of a total of 110 hemorrhagic tumors 23 (21%) were benign and 6 (5%) low-grade. The tumoral origin of cerebral hematoma is not always correctly diagnosed by non-contrast-enhanced CT and angiography, and therefore, in the presence of a hematoma with an "atypical" appearance, it is advisable to complete the diagnostic investigations with contrast-enhanced CT or MRI for the purposes of better planning surgical evacuation of hematoma and tumor removal, bearing in mind the high incidence of bleeding in benign and low-grade tumors as well as the optimal short and long-term results obtained with surgery.     

On-the-field management of athletic head injuries

Head injuries are prevalent in collision sports. Concussions represent the relatively benign end of the spectrum of injuries. Severe closed head injuries include epidural hematomas, acute subdural hematomas, intracerebral hematomas, intraventricular hematomas, subarachnoid hemorrhages, and diffuse axonal injuries. Second impact syndrome represents a severe cerebral autoregulatory dysfunction that can lead to death in an athlete who sustains a second (often minor) closed head trauma while still symptomatic from a previous head injury. Generally, athletes who have suffered a severe closed head injury should not return to play. Exceptions include athletes asymptomatic for 1 year who return to a noncontact sport and those who recover completely from an epidural hematoma without underlying brain injury. Several guidelines for returning athletes to play have been proposed and are commonly used. The team physician has the responsibility of on-the-field evaluation and management of athletes with head injuries, as well as of advising them when it is safe to return to play.     

High intraoperative blood loss may be a risk factor for postoperative hematoma

The authors studied the incidence of postoperative intracranial hematoma to improve care after intracranial surgery. Five years (1995-1999) of surgical records were analyzed retrospectively. Patients were included if evacuation of an intracranial postoperative hematoma was reported. A control group was randomly selected. Forty-nine patients (0.8%) had postoperative hematomas requiring evacuation. The amount of intraoperative blood loss was significantly larger in the hematoma group (762 +/-735 mL [median 500 mL]) than in the control group (415 +/-403 mL; median 300 mL) (P = 0.004). Clinical deterioration occurred within the first 24 hours in 80%, within 6 hours in 51%, and within 1 hour in 12% of the patients. Those who deteriorated within 24 hours had a faster and more life-threatening deterioration than those who had a hematoma after 24 hours. A decreased level of consciousness was found in 61% and increased focal neurologic signs were found in 33% of the patients. An elevated intracranial pressure was seen significantly more often in the hematoma group (9/10 patients, 90%) than in the control group (1/8 patients, 12.5%) (P = 0.001). In this study, a large amount of intraoperative blood loss and elevated intracranial pressure were warning signs of postoperative hematoma and should alert the clinician to the increased risk. Most hematomas occurred within 24 hours after surgery, and in this time period the deterioration was more severe compared with the hematomas that occurred later.     

Short-term and long-term safety of deep brain stimulation in the treatment of movement disorders

OBJECT: The object of this study was to assess the long-term safety of deep brain stimulation (DBS) in a large population of patients with a variety of movement disorders. METHODS: All patients treated with DBS at the authors' center between 1995 and 2005 were assessed for intraoperative, perioperative, and long-term adverse events (AEs). A total of 319 patients underwent DBS device implantation. Of these 319, 182 suffered from medically refractory Parkinson disease; the other patients had essential tremor (112 patients), dystonia (19 patients), and other hyperkinetic movement disorders (six patients). Intraoperative AEs were rare and included vasovagal response in eight patients (2.5%), syncope in four (1.2%), severe cough in three (0.9%), transient ischemic attack in one (0.3%), arrhythmia in one (0.3%), and confusion in one (0.3%). Perioperative AEs included headache in 48 patients (15.0%), confusion in 16 (5.0%), and hallucinations in nine (2.8%). Serious intraoperative/perioperative AEs included isolated seizure in four patients (1.2%), intracerebral hemorrhage in two patients (0.6%), intraventricular hemorrhage in two patients (0.6%), and a large subdural hematoma in one patient (0.3%). Persistent long-term complications of DBS surgery included dysarthria (4.0%), worsening gait (3.8%), cognitive dysfunction (4.0%), and infection (4.4%). Revisions were completed in 25 patients (7.8%) for the following reasons: loss of effect, lack of efficacy, infection, lead fracture, and lead migration. Hardware-related complications included 12 lead fractures and 10 lead migrations. CONCLUSIONS: The authors conclude that in their 10-year experience, DBS has proven to be safe for the treatment of medically refractory movement disorders.     

Risk of postoperative hemorrhage after intracranial surgery after early nadroparin administration: results of a prospective study

OBJECTIVE: Early postoperative pharmacological prophylaxis of deep vein thrombosis after intracranial surgery is still a matter of debate because of concerns regarding the formation of postoperative hematoma. The objective of this study was to prospectively analyze the rate of postoperative hemorrhage during a 3-year period of early postoperative administration of the low molecular weight heparin nadroparin (Fraxiparin) plus compression stockings in a large cohort of patients undergoing intracranial surgery. METHODS: A total of 2823 intracranial neurosurgical procedures, performed between June 1999 and 2002, were studied. Of these operations, 1319 (46.7%) were major intracranial surgical procedures (Group 1). Group 2 comprised 1504 operations (53.3%) considered to be minor surgical procedures (e.g., shunt procedures, biopsies). All patients except those with transnasal transsphenoidal removal of pituitary tumors underwent early postoperative imaging (computed tomography or magnetic resonance imaging) to determine postoperative hemorrhage. All significant postoperative hematomas (defined as those requiring surgical evacuation because of relevant space occupation and/or neurological deterioration) were treated surgically. Prophylaxis of venous thromboembolic events included early (<24 h) postoperative administration of 0.3 ml nadroparin subcutaneously plus intra- and postoperative compression stockings until discharge. RESULTS: Forty-three major postoperative hemorrhages (1.5%) were observed after 2823 intracranial procedures (95% confidence interval, 1.1-2.05). Forty-two (3.2%) of 1319 postoperative hematomas occurred in patients undergoing major intracranial procedures (Group 1). There was only 1 (0.07%) significant hemorrhage after 1504 minor intracranial procedures (Group 2). A subgroup analysis of patients who needed preoperative anticoagulation because of medical comorbidity did not reveal an increased frequency of postoperative hematoma when anticoagulation was stopped 24 hours before surgery P = 0.1, chi(2) test; 95% confidence interval, 0.89-3.0). CONCLUSION: This report describes the largest prospective study conducted to date to determine the hemorrhage rate after early postoperative anticoagulation. The results support the concept of postoperative pharmacological thromboembolic prophylaxis in patients undergoing intracranial surgery.     

Postoperative extradural hematomas: computed tomographic survey of 1105 intracranial operations

We reviewed the computed tomographic findings after 1055 intracranial operations to determine the incidence of postoperative extradural hematomas. There were 11 medium and 5 large hematomas after 1055 operations (1.0%). Ten of the 16 hematomas were operated upon (10/1055, 0.9%). Four of the 10 hematomas were seen after 278 brain tumor removals (1.4%), another four after 190 aneurysmal operations (2.1%), one after 14 intracerebral hematoma removals (7.1%), and the last one after 251 ventricular shunting or drainage procedures (0.4%). In 4 of the 10 operated hematomas, sites were regional, in five sites were adjacent, and in one the site was distant. All of the five adjacent hematomas extended downward from a lower rim of the operative locus. Causes were analyzed in the three types of the hematomas. In case of the regional hematomas, the causes were incomplete hemostasis of the dura mater or the bone in all four patients, nonperformance of central stay sutures in three, systemic hypertension in one, and hypofibrinogenemia in one. In the adjacent hematomas, we could find dural separation at an edge of craniotomy in all five patients, abrupt collapse of the brain in all, ventricular dilatation in two, and systemic hypertension during immediate postoperative period in two. In one distant hematoma, ventricular dilatation and ventricular shunting procedure were themselves thought to be the causal factors.     

Functional neurosurgery in the MRI environment.

OBJECTIVE: The purpose of this study was to evaluate the feasibility of microelectrode recording, electrical stimulation, and electrode position checking during functional neurosurgical procedures (DBS, lesion) in the interventional magnetic resonance imaging (iMRI) environment. METHODS: Seventy-six surgical procedures for DBS implant or radiofrequency lesion were performed in an open 0.2 T MRI operating room. DBS implants were performed in 54 patients (72 surgical procedures) and unilateral radiofrequency lesions in three for a total of 76 surgeries in 57 patients. Electrophysiological studies including macrostimulation and microelectrode recordings for localization were obtained in the 0.5 to 10 mT fringes of the magnetic field in 51 surgeries. MRI confirmation of the electrode position during the procedure was performed after electrophysiological localization. RESULTS: The magnetic field associated with the MRI scanner did not contribute significant noise to microelectrode recordings. Anatomical confirmation of electrode position was possible within the MRI artifact from the DBS hardware. Symptomatic hemorrhage was detected in two (2.6 %) patients during the operation. Image quality of the 0.2 T MRI scan was sub-optimal for anatomical localization. However, image fusion with pre-operative scans permitted excellent visualization of the DBS electrode tip in relation to the higher quality 1.5 T MRI anatomical scans. CONCLUSION: This study shows that conventional stereotactic localization, microelectrode recordings, electrical stimulation, implant of DBS hardware, and radiofrequency lesion placement are possible in the open 0.2 T iMRI environment. The convenience of having an imaging modality that can visualize the brain during the operation is ideal for stereotactic procedures.     

Removal of intramedullary rods after femoral shaft fracture.

We are reporting a retrospective review of the removal of 60 intramedullary rods in 58 patients. All fractures had healed at the time of rod extraction. The implant was removed from 34 asymptomatic patients (36 femurs). Twenty-four patients (24 femurs) had preoperative symptoms attributed to the femoral rod. Fourteen patients had symptoms about the greater trochanter preoperatively, five patients had symptoms referable to the knee, and five had infections about the femoral implant. Problems encountered included broken rods in five femurs, one of which was not apparent on preoperative radiographs. There were six patients (six femurs) who required further hospital care for postoperative hematomas. The development of a significant hematoma was not related to the location of the fracture, the presence of interlocking devices requiring removal, the length of time since injury, the performance of this procedure as an inpatient or outpatient, or the presence or absence of a functional drain. Of the 10 patients (10 femurs) who had proximal heterotopic ossification Brooker stage 2 or greater, wound hematomas developed in four patients (40%). There were no refractures. Although there may be an indication for rod removal, we do not recommend the procedure in asymptomatic patients.     

Delayed postoperative spinal epidural hematomas.

BACKGROUND CONTEXT: Symptomatic epidural hematomas after spinal surgery are uncommon and are usually diagnosed within 24 hours after surgery. PURPOSE: We report a series of delayed epidural hematomas in a subset of patients who awoke from surgery neurologically unchanged and then deteriorated more than 3 days after their index procedure. The goals of this report are to outline the clinical presentation, radiological characteristics and outcome of this uncommon entity. STUDY DESIGN/SETTING: We retrospectively reviewed the database of six spine surgeons over a 4-year period, looking for presence of epidural hematomas as a cause of clinical deterioration after an asymptomatic postoperative period of at least 3 days. PATIENT SAMPLE: We identified a subset of patients who awoke from surgery neurologically unchanged and then deteriorated more than 3 days after spinal surgery. A total of 4,018 patients were identified over the 4-year period of review. OUTCOME MEASURES: Presence of spinal epidural hematoma as a cause of clinical deterioration after an asymptomatic period of at least 3 days. The medical records, including the history, physical, preoperative and postoperative neurological examinations, as well as plain radiographs and magnetic resonance images, were reviewed. METHODS: We retrospectively reviewed the database of six spine surgeons over a 4-year period. We looked for delayed spinal epidural hematomas as a cause of clinical deterioration after an asymptomatic postoperative period of at least 3 days. We examined potential risk factors for spinal extradural hematomas. RESULTS: Of 4,018 patients, we identified seven with spinal epidural hematoma who presented more than 3 days after their index procedure. The initial presenting symptom, which heralded the subsequent onset of neurological deterioration, consisted of severe sharp pain with radiation to the extremities. The average time to neurological deterioration was 5.3 days. Fifty-seven percent of the patients had multiple previous spinal surgeries at the site of the epidural hematoma. Surgical evacuation of the epidural hematomas resulted in neurological improvement in five patients. Persistent neurological deficits were observed in two patients. CONCLUSION: Delayed spinal epidural hematomas are an uncommon cause of delayed deterioration after spinal surgery. Previous surgery with attendant scarring that results in impairment of clot resorption may be a contributing factor in the development of the condition.