Asian race/ethnicity as a risk factor for bile duct injury during cholecystectomy.

Iatrogenic bile duct injury (BDI) is an uncommon but serious complication of cholecystectomy, with identified risk factors of acute cholecystitis, male sex, older age, and aberrant biliary anatomy. The Nationwide Inpatient Sample (1998-2006) was queried for cholecystectomy performed on hospital day 0 or 1. Bile duct injury repair procedure codes were used as a surrogate for BDI. We identified 377,424 patients who underwent cholecystectomy, with 1124 BDIs (0.3%). On multivariate logistic regression analysis, Asian race/ethnicity was a significant risk factor for BDI (odds ratio [OR], 2.26; 95% confidence interval [CI], 1.59-3.23; P < .001). This persisted for laparoscopic (OR, 2.62; 95% CI, 1.28-5.39; P = .009) and open (2.21; 1.59-3.07; P < .001) cholecystectomies. No other race/ethnicity was identified as a risk factor for BDI. We report a new finding that Asian race/ethnicity is a significant risk factor for BDI in laparoscopic and open cholecystectomies.

Persistent outpatient hyperglycemia is independently associated with survival, recurrence and malignant degeneration following surgery for hemispheric low grade gliomas.

OBJECTIVE: Hyperglycemia has been shown to augment tumor growth in vitro. However, the effects of persistent hyperglycemia on survival, recurrence and malignant degeneration in patients undergoing surgery for low grade gliomas remain unknown. METHODS: All patients who underwent a craniotomy for hemispheric low grade glioma (WHO grade II) from 1996 to 2006 at a single institution were retrospectively reviewed. Persistent hyperglycemia was defined as serum glucose >180 microg/dl occurring three or more times between 1 and 3 months post-operatively. The independent association of outpatient glucose levels and recorded clinical and treatment variables with overall survival, tumor recurrence and malignant degeneration was assessed via separate multivariate proportional-hazards regression analyses. RESULTS: In this study, 182 patients (89 fibrillary astrocytomas, 82 oligodendrogliomas and 11 mixed gliomas) were available for analysis. Eighteen (10%) patients experienced persistent hyperglycemia. Patients experiencing persistent hyperglycemia were older (44 +/- 16 versus 34 +/- 15) and more frequently diabetic [3 (17%) versus 4 (2%)]. All other clinical and treatment variables were not significantly different between the two cohorts. After adjusting for inter-group differences including age and diabetes and variables associated with survival and recurrence, persistent hyperglycemia was independently associated with decreased survival (p=0.001), increased recurrence (p=0.0001) and increased malignant degeneration (p<0.0001). This remained true after excluding all patients with diabetes and those on continued steroid administration. Five-year overall survival, progression-free survival and malignancy-free survival for persistent hyperglycemia versus relatively euglycemic cohorts were 43% versus 84%, 16% versus 46% and 46% versus 77%, respectively. DISCUSSION: These findings may provide useful insight for increasing survival, decreasing tumor recurrence and decreasing malignant degeneration in patients undergoing surgery for low grade gliomas.

Recurrent disc herniation and long-term back pain after primary lumbar discectomy: review of outcomes reported for limited versus aggressive disc removal.

OBJECTIVE: It remains unknown whether aggressive disc removal with curettage or limited removal of disc fragment alone with little disc invasion provides a better outcome for the treatment of lumbar disc herniation with radiculopathy. We reviewed the literature to determine whether outcomes reported after limited discectomy (LD) differed from those reported after aggressive discectomy (AD) with regard to long-term back pain or recurrent disc herniation. METHODS: A systematic MEDLINE search was performed to identify all studies published between 1980 and 2007 reporting outcomes after AD or LD for a herniated lumbar disc with radiculopathy. The incidence of short- and long-term recurrent back or leg pain and recurrent disc herniation was assessed from each reported LD or AD cohort and the cumulative incidence compared. RESULTS: Fifty-four studies (60 discectomy cohorts) met the inclusion criteria, reporting the outcomes of 13 359 patients after lumbar discectomy (LD, 6135 patients; AD, 7224 patients). The reported incidence of short-term recurrent back or leg pain was similar after LD (mean, 14.5%; range, 7-16%) and AD (mean, 14.1%; range, 6-43%) (P < 0.01). However, more than 2 years after surgery, the reported incidence of recurrent back or leg pain was 2.5-fold less after LD (mean, 11.6%; range, 7-16%) compared with AD (mean, 27.8%; range, 19-37%) (P < 0.0001). The reported incidence of recurrent disc herniation after LD (mean, 7%; range, 2-18%) was greater than that reported after AD (mean, 3.5%; range, 0-9.5%) (P < 0.0001). CONCLUSION: Review of the literature demonstrates a greater reported incidence of long-term recurrent back and leg pain after AD but a greater reported incidence of recurrent disc herniation after LD. Prospective, randomized trials are needed to firmly assess this possible difference.

Outcome of Chiari-associated syringomyelia after hindbrain decompression in children: analysis of 49 consecutive cases.

OBJECTIVE: Chiari I malformation is complicated by syringomyelia in many cases. Hindbrain decompression remains first-line surgical treatment; however, the incidence, time course, and predictors of syrinx resolution remain unclear. We set out to determine predictors of syrinx improvement after hindbrain decompression for Chiari I- associated syringomyelia. METHODS: Forty-nine consecutive pediatric patients undergoing posterior fossa decompression for Chiari I-associated syringomyelia were followed with serial magnetic resonance imaging evaluations postoperatively. Clinical, radiological, and operative variables were assessed as predictors of syrinx improvement as a function of time using Kaplan-Meier plots and log-rank analysis. RESULTS: Mean patient age was 11 +/- 5 years. Syringomyelia was symptomatic in 39 (80%) and asymptomatic in 10 (20%) cases. Twenty-one (54%) patients experienced symptom resolution (median, 4 mo postoperatively). Twenty-seven (55%) patients experienced radiographic improvement in syringomyelia (median, 14 mo postoperatively). After hindbrain decompression, motor symptoms were associated with a 2.35 increased hazard ratio for symptom improvement (P = 0.031) versus all other symptoms. Among patients with sensory deficits, dysesthesia was associated with a 3.12 increased hazard ratio for symptom improvement (P = 0.032) versus symptoms of paresthesia or anesthesia. CONCLUSION: In our experience, just more than one-half of patients with Chiari- associated syringomyelia demonstrated clinical and radiographic improvement after hindbrain decompression. Median time to radiographic improvement lagged behind clinical improvement by 10 months. Motor symptoms were more likely to improve with hindbrain decompression. Paresthesia or anesthesia symptoms were less likely to improve with hindbrain decompression. These findings may help guide surgical decision making and aid in patient education.

Intraoperative ultrasonography as a guide to patient selection for duraplasty after suboccipital decompression in children with Chiari malformation Type I.

OBJECT: Indications for duraplasty in treatment of Chiari malformation Type I (CM-I) remain unclear. In the present study, the authors evaluate their surgical experience to determine whether intraoperative ultrasonography is effective in the selection of patients with CM-I who can be adequately treated with craniectomy alone without duraplasty. METHODS: The authors reviewed the records of 256 children who underwent first-time hindbrain decompression for CM-I. Craniectomy alone (without duraplasty) was performed when intraoperative ultrasonography suggested adequate decompression of the subarachnoid spaces ventral and dorsal to the tonsils after suboccipital craniectomy alone. Duraplasty was performed if intraoperative ultrasonography demonstrated persistent dural compression of the tonsils following craniectomy. Symptom recurrence as a function of time was compared between cases of duraplasty versus suboccipital decompression alone stratified by extent of tonsillar herniation. RESULTS: Duraplasty was performed in 140 patients (55%), and suboccipital decompression alone was performed in 116 patients (45%). Patients underwent follow-up for 29 +/- 15 months. Symptoms included headache in 192 patients (75%) and lower cranial nerve and brainstem dysfunction in 68 (27%). In 38 patients (15%) there was tonsillar herniation rostral to the C-1 lamina, in 195 (76%) it extended between the C-1 and C-2 lamina, and in 23 patients (9%) there was herniation caudal to the lower border of the C-2 lamina. In children with tonsillar herniation caudal to C-1, ultrasonography-guided suboccipital decompression alone was associated with a 2-fold increase in the risk of symptom recurrence compared with those who also underwent duraplasty (p = 0.01). In children with tonsillar herniation rostral to C-1, outcome was equivalent between suboccipital decompression alone and duraplasty (p = 0.41). CONCLUSIONS: In the setting of moderate-to-severe tonsillar CM-I, intraoperative ultrasonography demonstrating decompression of the subarachnoid spaces ventral and dorsal to the tonsils may not effectively select patients in whom bone decompression alone is sufficient. Duraplasty may be warranted in cases of tonsillar herniation that extends below the C-1 lamina regardless of intraoperative ultrasonography findings. More objective cerebrospinal fluid flow or volumetric measures may be needed intraoperatively to guide duraplasty in patients with more pronounced tonsillar herniation.

Use of Gliadel (BCNU) wafer in the surgical treatment of malignant glioma: a 10-year institutional experience.

BACKGROUND: Gliadel (polifeprosan 20 with carmustine [BCNU] implant) is commonly used for local delivery of BCNU to high-grade gliomas after resection and is associated with increased survival. Various complications of Gliadel wafers have been reported but not consistently reproduced. We set out to characterize Gliadel-associated morbidity in our 10-year experience with Gliadel wafers for treatment of malignant glioma. METHODS: We retrospectively reviewed records of 1013 patients undergoing craniotomy for resection of malignant brain astrocytoma (World Health Organization grade III/IV disease). Perioperative morbidity occurring within 3 months of surgery was assessed for patients and compared between patients receiving versus not receiving Gliadel wafer. Overall survival was assessed for all patients. RESULTS: A total of 1013 craniotomies were performed for malignant brain astrocytoma. A total of 288 (28%) received Gliadel wafer (250 glioblastoma multiforme (GBM), 38 anaplastic astrocytoma/anaplastic oligodendroglioma (AA/AO), 166 primary resection, 122 revision resection). Compared with the non-Gliadel cohort, patients receiving Gliadel were older (55 +/- 14 vs. 50 +/- 17, P = .001) and more frequently underwent gross total resection (75% vs 36%, P < .01) but otherwise similar. Patients in Gliadel versus non-Gliadel cohorts had similar incidences of perioperative surgical site infection (2.8% vs. 1.8%, P = .33), cerebrospinal fluid leak (2.8% vs. 1.8%, P = .33), meninigitis (.3% vs. .3%, P = 1.00), incisional wound healing difficulty (.7% vs. .4%, P = .63), symptomatic malignant edema (2.1% vs. 2.3%, P = 1.00), 3-month seizure incidence (14.6% vs. 15.7%, P = .65), deep-vein thrombosis (6.3% vs. 5.2%, P = .53), and pulmonary embolism (PE) (4.9% vs. 3.7%, P = .41). For patients receiving Gliadel for GBM, median survival was 13.5 months after primary resection (20% alive at 2 years) and 11.3 months after revision resection (13% alive at 2 years). For patients receiving Gliadel for AA/AO, median survival was 57 months after primary resection (66% alive at 2 years) and 23.6 months after revision resection (47% alive at 2 years). CONCLUSION: In our experience, use of Gliadel wafer was not associated with an increase in perioperative morbidity after surgical treatment of malignant astrocytoma.

Symptom recurrence after suboccipital decompression for pediatric Chiari I malformation: analysis of 256 consecutive cases.

OBJECTIVE: Symptom recurrence remains a problem for some patients after surgical decompression for Chiari I malformation. We set out to identify variables at presentation that could identify subgroups most likely to experience incomplete symptom relief after hindbrain decompression for Chiari I malformation. MATERIALS AND METHODS: We retrospectively reviewed the records of all pediatric patients undergoing first-time suboccipital decompression for Chiari I malformation over a 10-year period. Measured outcomes included (1) persistence or recurrence of symptoms regardless of severity and (2) need for revision decompression. RESULTS: Two hundred fifty-six children (10 5 years old) underwent surgery for Chiari I malformation and were followed up for a mean of 27 months. Presenting symptoms included headache in 192 (75%) patients and brainstem or cranial nerve symptoms in 68 (27%) patients. Fifty-seven (22%) patients experienced mild to moderate symptom recurrence. Nineteen (7%) patients required revision decompression for significant symptom recurrence. Headache was 70% more likely to persist or recur versus cranial nerve or brainstem symptoms (relative risk 1.70, p < 0.05). Vertigo and frontal headache independently increased the odds of symptom recurrence 2.9- and 1.5-fold, respectively. Each increasing year of preoperative headache duration was independently associated with 15% increase in likelihood of symptom persistence (p < 0.05). Severe tonsilar ectopia (caudal to C2 lamina) was twice as likely to require revision decompression (14% versus 6%). CONCLUSION: In our experience, recurrence of mild symptomatology not severe enough to justify revision surgery may occur in nearly a fifth of patients after surgery. Headache was more likely to recur than objective cranial nerve or brainstem symptoms. Increasing duration of headaches, frontal headaches, and vertigo may be more refractory symptoms of Chiari I malformation.

Suboccipital decompression for Chiari malformation-associated scoliosis: risk factors and time course of deformity progression.

OBJECT: Chiari malformation Type I (CM-I) is often associated with scoliosis. It remains unclear which subgroups of patients are most likely to experience progression of spinal deformity after cervicomedullary decompression. The authors' goal was to determine the time frame of curvature progression and assess which patient subgroups are at greatest risk for progression of spinal deformity after surgery. METHODS: The authors retrospectively reviewed the records of all pediatric patients with significant scoliosis in whom suboccipital decompression was performed to treat for CM-I during a 10-year period at a single academic institution. Clinical, radiological, and operative variables were assessed as independent factors for failure (worsening of scoliosis) by using a univariate regression analysis. RESULTS: Twenty-one children (mean age 9 +/- 3 years; 4 male) underwent hindbrain decompression for CM-I-associated scoliosis and were followed for a mean of 39 months. All patients harbored a syrinx. Eight patients (38%) experienced improvement in scoliosis curvature, whereas 10 (48%) suffered a progression. Thoracolumbar junction scoliosis (p = 0.04) and failure of the syrinx to improve (p = 0.05) were associated with 5- and 4-fold respective increases in the likelihood of deformity progression. Each increasing degree of preoperative Cobb angle was associated with an 11% increase in the likelihood of scoliotic curve progression (p < 0.05). CONCLUSIONS: Over one third of patients with CM-I-associated scoliosis will improve after cervicomedullary decompression alone. Cervicomedullary decompression is a good first-line option, particularly in children with concordant posterior fossa symptoms. Patients presenting with more severe scoliosis (increasing Cobb angle) or scoliosis that crosses the thoracolumbar junction may benefit from earlier orthopedic involvement and should be monitored regularly for curvature progression after cervicomedullary decompression. In cases in which there is a failure of the syrinx to show improvement after suboccipital decompression, the patients are also more likely to develop curvature progression.

Correlation of hindbrain CSF flow and outcome after surgical decompression for Chiari I malformation.

OBJECTIVE: Many patients with symptomatic Chiari I malformation experience symptom recurrence after surgical decompression. Improved radiographic predictors of outcome are needed to better select patients most likely to benefit from surgical intervention. We examined whether ventral or dorsal cerebrospinal fluid (CSF) flow dynamics assessed by cine phase-contrast MRI scans could predict response to posterior fossa decompression for Chiari I malformation. METHODS: Forty-four consecutive pediatric patients undergoing pre-operative cine phase-contrast MRI followed by posterior fossa decompression for Chiari I malformation were retrospectively reviewed. The association of pre-operative ventral or dorsal CSF flow abnormalities at the foramen magnum with symptom-free survival after surgical decompression was assessed via Kaplan-Meier plots and log-rank analysis. RESULTS: Mean +/- SD age at time of surgery was 8 +/- 6 years. Sixteen (36%) patients demonstrated decreased CSF flow dorsal to the cervico-medullary brainstem alone. Fourteen (32%) patients demonstrated abnormal CSF flow both ventral and dorsal to the cervico-medullary brainstem. Fourteen (32%) had normal hindbrain CSF flow. Overall, 13 (30%) patients experienced some degree of symptom recurrence by last follow-up (mean of 27 +/- 16 months post-operatively). Symptom recurrence did not differ as a function of degree of tonsilar ectopia (p = 0.55). Abnormal CSF flow dorsal to the cervico-medullary brainstem was not associated with symptom recurrence after surgical decompression (p = 0.10). However, combined pre-operative ventral and dorsal CSF flow abnormality was associated with a significant reduction (2.6-fold) in the risk of post-operative symptom recurrence (p < 0.05). Only one patient (7%) with pre-operative ventral and dorsal CSF flow pathology experienced symptom recurrence 3.5 years after surgery versus 12 (40%) patients without ventral CSF flow pathology. There were otherwise no differences in baseline clinical, radiological, or operative variables between patients with abnormal versus normal ventral CSF flow. CONCLUSION: The presence of decreased CSF flow both ventral and dorsal to the cervico-medullary brainstem was associated with improved response to hindbrain decompression for Chiari I malformation in children. Cine phase-contrast MRI may be a useful tool for surgical risk stratification and identifying patients that may be optimal surgical candidates. Combined ventral and dorsal hindbrain CSF flow pathology may better predict response to posterior fossa decompression compared to dorsal CSF flow pathology alone.