On the value of routine prothrombin time screening in elective neurosurgical procedures

The role of extended coagulation screening in adult cranial neurosurgery

Introduction

Postoperative hemorrhage after adult cranial neurosurgery is a serious complication with substantial morbidity and mortality.

Research question

We investigated if an extended preoperative screening and an early treatment of previously undetected coagulopathies may decrease the risk of postoperative hemorrhage.

Methods

A prospective study cohort of patients undergoing elective cranial surgery and receiving the extended coagulatory work-up were compared to a propensity matched historical control cohort. The extended work-up included a standardized questionnaire on the patient's bleeding history as well as coagulatory tests of Factor XIII, von-Willebrand-Factor and PFA-100®. Deficiencies were substituted perioperatively. The primary outcome was determined as the surgical revision rate due to postoperative hemorrhage.

Results

The study cohort and the control cohort included 197 cases each, without any significant difference in the preoperative intake of anticoagulant medication (p ​= ​.546). Most common interventions were resections of malignant tumors (41%), benign tumors (27%) and neurovascular surgeries (9%) in both cohorts. Imaging revealed postoperative hemorrhage in 7 cases (3.6%) in the study cohort and 18 cases (9.1%) in the control cohort (p ​= ​.023). Of these, revision surgeries were significantly more common in the control cohort with 14 cases (9.1%) compared to 5 cases (2.5%) in the study cohort (p ​= ​.034). Differences in mean intraoperative blood loss were not significant with 528 ​ml in the study cohort and 486 ​ml in the control cohort (p ​= ​.376).

Conclusion

Preoperative extended coagulatory screening may allow for revealing previously undiagnosed coagulopathies with subsequent preoperative substitution and thereby reduction of risk for postoperative hemorrhage in adult cranial neurosurgery.

Application of multimodal MRI and radiologic features for stereotactic brain biopsy: insights from a series of 208 patients

OBJECTIVES

We reviewed our institutional experience during a 10-year period for improvement of safety and efficacy of stereotactic biopsy procedures.

METHODS

We performed a retrospective review of inpatient summaries, stereotactic worksheets and radiologic investigations of 208 consecutive patients, who underwent MRI-guided stereotactic biopsies between March 2010 and March 2020.

RESULTS

The overall diagnostic yield was 96.2%. CT-confirmed intracranial hemorrhage occurred in 17 patients (8.2%), and the overall mortality rate was 0.5%. Combined MRS and PWI helped target selection in 27 cases (13.0%), the diagnostic yield was 100%. The results of the regression analysis revealed that non-diagnostic biopsy specimen significantly correlated with the cystic trait (p<.01) and edema of lesions (p<.05). Enhancement (p<.01) is shown to be an important factor for obtaining a diagnostic biopsy. Furthermore, the edema trait of lesions (p<.01) showed the important factors of hemorrhage.

CONCLUSIONS

The radiological features of lesions and use of the most suitable MRI sequences during biopsy planning are recommended ways to improve the diagnostic yield and safety of this technique.

Preoperative laboratory testing before pediatric neurosurgery: an NSQIP-Pediatrics analysis

OBJECTIVES

The goal of this study was to evaluate clinical predictors of abnormal preoperative laboratory values in pediatric neurosurgical patients.

METHODS

Data obtained in children who underwent a neurosurgical operation were extracted from the prospective National Surgical Quality Improvement Program-Pediatrics (NSQIP-P, 2012-2013) registry. Multivariable logistic regression evaluated predictors of preoperative laboratory values that might require further evaluation (white blood cell count < 2000/μl, hematocrit < 24%, platelet count < 100,000/μl, international normalized ratio > 1.4, or partial thromboplastin time > 45 seconds) or a preoperative transfusion (within 48 hours prior to surgery). Variables screened included patient demographics; American Society of Anesthesiologists (ASA) physical designation classification; comorbidities; recent steroid use, chemotherapy, or radiation therapy; and admission type. Predictive score validation was performed using the NSQIP-P 2014 data.

RESULTS

Of the 6556 patients aged greater than 2 years, 68.9% (n = 5089) underwent laboratory testing, but only 1.9% (n = 125) had a critical laboratory value. Predictors of a laboratory abnormality were ASA class III-V; diabetes mellitus; hematological, hypothrombotic, or oncological comorbidities; nutritional support; recent chemotherapy; systemic inflammatory response syndrome; and a nonelective hospital admission. These 9 variables were used to create a predictive score, with a single point assigned for each predictor. The prevalence of critical values in the validation population (NSQIP-P 2014) of patients greater than 2 years of age was 0.3% with a score of 0, 1.0% in those with a score of 1, 1.6% in those with a score of 2, and 6.2% in those with a score ≥ 3. Higher score was predictive of a critical value (OR 2.33, 95% CI 1.91-2.83, p < 0.001, C-statistic 0.76) and with the requirement of a perioperative transfusion (intraoperatively or within 72 hours postoperatively; OR 1.42, 95% CI 1.22-1.67, p < 0.001) in the validation population. Moreover, when the same score was applied to children aged 2 years or younger, a greater score was predictive of a critical value (OR 2.47, 95% CI 2.15-2.84, p < 0.001, C-statistic 0.76).

CONCLUSIONS

Critical laboratory values in pediatric neurosurgical patients are largely predicted by clinical characteristics, and abnormal preoperative laboratory results are rare in patients older than 2 years of age without comorbidities who are undergoing elective surgery. The NSQIP-P critical preoperative laboratory value scale is proposed to indicate patients with the highest odds of an abnormal value. The scale can assist with triaging preoperative testing based on the surgical risk, as determined by the treating surgeon and anesthesiologist.

Preoperative screening for coagulopathy in elective neurosurgical patients in Wellington Regional Hospital and survey of practice across Australia and New Zealand

It is common practice to perform pre-operative coagulation screening in elective neurosurgery patients, including international normalised ratio (INR) and activated partial thromboplastin time (aPTT). We present a retrospective analysis of 1143 elective neurosurgical patients at Wellington Regional Hospital (WRH) in New Zealand between 2013 and 2017 on whom coagulation screening including INR and aPTT was performed prior to surgery. 21 patients (1.8%) had clinically significant derangements on coagulation profile defined as raised INR or prolonged aPTT. 15 (1.3%) of these patients would be expected to have derangement based on previous history and 6 (0.5%) had unexpected derangements in coagulation profile. Of the 6 patients with unexpected derangements in coagulation profile, all had raised aPTT, none had preoperative correction of coagulopathy and none had bleeding complications or mortality. The cost of coagulation screening across the duration of the study was $68,009 New Zealand Dollars (NZD). A survey of major elective neurosurgery units in Australia and New Zealand found that 85% perform routine laboratory coagulation screening. In the 15% who do not perform laboratory coagulation screening, none use a standardised questionnaire to screen for coagulopathy. We developed a structured questionnaire to assist in detection of coagulopathy in elective neurosurgery patients. Our findings suggest that there is limited value in performing indiscriminate laboratory coagulation screening in patients with no risk factors on history. Despite this, routine laboratory coagulation screening is common practice in Australia and New Zealand. We propose a structured questionnaire to guide laboratory testing and discussions with haematology colleagues.

Value of Routine Preoperative Tests for Coagulation Before Elective Cranial Surgery. Results of an Institutional Audit and a Nationwide Survey of Neurosurgical Centers in Pakistan

BACKGROUND

Routine preoperative blood testing has become a dogma. The general practice is to order preoperative workup as a knee-jerk response rather than individualize it for each patient. The fact that the bleeding brain tends to swell, which coupled with limited options for proximal control, packing, and overall hemostasis, leads to an overemphasis on the preoperative coagulation profile.

MATERIAL AND METHODS

This is a retrospective review of the medical records of patients admitted at Aga Khan University Hospital from January 2010 to December 2015 for an elective craniotomy. The hospital registry was used to identify files for review. Data were collected on a predefined proforma. A nationwide survey was performed, and 30 neurosurgery centers were contacted across Pakistan to confirm the practice of preoperative workup.

RESULTS

The survey revealed that all centers had a similar practice of preoperative workup. This included complete blood count, serum electrolytes, and coagulation profile, including prothrombin time, activated partial thromboplastin time (aPTT), and international normalized ratio (INR). A total of 1800 files were reviewed. Nine (0.5%) patients were found to have deranged clotting profile without any predictive history of clotting derangement; 56% were male and 44% were female. Median age was 32 years with an interquartile range of 27 years. Median aPTT was (40.8 with 20.8 IQR). Median INR was (1.59 with 0.48 IQR). Median blood loss was (400 with 50 IQR). No significant association between coagulation profile (aPTT, INR) and blood loss was found (P = 0.85, r = -0.07).

CONCLUSIONS

We conclude that patients without a history of coagulopathy and normal physical examination do not require routine coagulation screening before elective craniotomy.

Preoperative laboratory data are associated with complications and surgical site infection in composite head and neck surgical resections

OBJECTIVES

1) Describe normal/abnormal preoperative laboratory testing incidence in head and neck (H&N) composite resections and 2) determine complication, surgical site infection (SSI), and transfusion predictors by laboratory test.

METHODS

The 2006 to 2013 NSQIP databases were queried for H&N composite resections. Laboratory data was categorized within, under, or above the normal reference range according to NSQIP definitions. Overall complications and SSI were analyzed with multivariable logistic regression analysis.

RESULTS

From 2006 to 2013, there were 1193H&N composite resections, of which 1135 (95.1%) underwent ≥1 preoperative laboratory test. Complete blood counts were obtained in 92.3%, basic metabolic panels in 90.7%, coagulation studies in 56.2%, and liver function tests (LFTs) in 52.6%. Low sodium was found in 11.5%, increasing complication odds by 2.30 (p = 0.005). High AST comprised 10.0% and increased complication odds (OR = 2.93, p = 0.012). Additionally, 9.2% had a high white blood cell (WBC) count and 3.5% had high platelets, increasing complications by 1.92 (p = 0.030) and 3.13 (p = 0.015), respectively. BUN, creatinine, total bilirubin, albumin, alkaline phosphatase, INR, PT, and aPTT abnormal values did not affect postoperative complications. Increased SSI odds were appreciated with low sodium (OR: 2.83, p = 0.002), high AST (OR: 6.85, p < 0.001), and high alkaline phosphatase (OR: 5.46, p = 0.007). Importantly, INR had no effect on transfusion rates. High PT, aPTT, or low platelets did not change transfusion odds.

CONCLUSION

Inflammatory markers are associated with complications but not SSI. High LFTs and low sodium are associated with complications and SSI. Coagulopathies did not increase transfusion rates. These findings identify laboratory studies to focus on during H&N resection preoperative assessments.

Preoperative assessment of haemostasis in patients undergoing stereotactic brain biopsy

Parenchymal hemorrhage is considered a major risk factor for perioperative morbidity in patients undergoing stereotactic brain biopsy. Studies on patients undergoing surgical procedures have suggested that evaluation of prothrombin time (PT) and activated partial thromboplastin time (aPTT) is of limited value with regard to prevention of haemorrhagic complications. However, this issue has not yet been addressed in patients undergoing stereotactic biopsy of intracranial lesions. We retrospectively analysed the medical records of 159 consecutive patients undergoing stereotactic biopsy of supratentorial intracranial lesions during a three-year period. Laboratory values (PT, aPTT, platelet count) were reviewed as well as clinical characteristics, modalities of surgical treatment, histopathological results and the postoperative course of patients. The overall diagnostic yield was 93.7%. Histopathological examination revealed glioma (WHO°I: 5, WHO°II: 25, WHO°III: 23, WHO°IV: 65), lymphoma (n = 14), inflammation (n = 8) and other entities (n = 6). Surgery-associated neurological deficits occurred in 7 patients (4.4%) and completely resolved in 6 of these patients. CT-confirmed intracranial hemorrhage occurred in 2 patients (1.3%) and in both cases, histopathological examination revealed glioblastoma. Results of hemostatic parameters (PT: 99 ± 13%, aPTT: 24 ± 3s, platelet count: 274 ± 87 10³/μL) were within normal range values in all patients and did not correlate with postsurgical morbidity. Standard assessment of haemostasis seems to be of limited value in patients with intracranial lesions undergoing stereotactic biopsy. Further studies regarding the intratumoural vasculature's impact on the risk of biopsy-related bleeding are necessary.

Safety of omitting routine bleeding tests prior to image-guided musculoskeletal core needle biopsy

PURPOSE

To evaluate the safety of withholding preprocedure international normalized ratio (INR) and platelet testing in patients undergoing musculoskeletal (MSK) core needle biopsy (CNB).

MATERIAL AND METHODS

Initially, a retrospective review of 1,162 consecutive patients undergoing MSK CNB with preprocedural INR and platelet testing was performed. Clinical (age, gender, bleeding disorder, liver disease, anticoagulation use, INR > 2, platelet count <50,000/ul) and biopsy factors (imaging modality, lesion type, biopsy needle gauge, number biopsy samples) were tested for association with bleeding complications. During the second phase, an additional 188 biopsies performed without preprocedural coagulation testing were studied. Categorical variables were compared using Chi-squared or Fisher's exact tests, continuous variables with a student t-test. Multivariate analysis was performed using logistic regression.

RESULTS

In the first phase, there was a complication rate of 2.6%, 30/1162. Of the 11 clinical and biopsy factors, soft tissue lesions (p = 0.029) and lesions biopsied under ultrasound (p = 0.048) had a higher rate of bleeding than bone lesions or lesions biopsied under CT, respectively. Only three patients had an INR >2, 0.3% (3/1162) and only four patients had platelet count <50,000/ul, 0.3% (4/1162). No patient with a bleeding complication had an abnormal preprocedure bleeding test. In the second phase, there was a bleeding complication rate of 1.1% (2/188).

CONCLUSION

Bleeding complications from MSK biopsy are low, even when preprocedure coagulation testing is omitted.

Incidence of Postoperative Hematomas Requiring Surgical Treatment in Neurosurgery: A Retrospective Observational Study

OBJECTIVE

We aimed to characterize the occurrence of postoperative hematoma (POH) after neurosurgery overall and according to procedure type and describe the prevalence of possible confounders.

METHODS

Patient data between 2010 and 2012 at the Department of Neurosurgery in Helsinki University Hospital were retrospectively analyzed. A data search was performed according to the type of surgery including craniotomies; shunt procedures, spine surgery, and spinal cord stimulator implantation. We analyzed basic preoperative characteristics, as well as data about the initial intervention, perioperative period, revision operation and neurologic recovery (after craniotomy only).

RESULTS

The overall incidence of POH requiring reoperation was 0.6% (n = 56/8783) to 0.6% (n = 26/4726) after craniotomy, 0% (n = 0/928) after shunting procedure, 1.1% (n = 30/2870) after spine surgery, and 0% (n = 0/259) after implantation of a spinal cord stimulator. Craniotomy types with higher POH incidence were decompressive craniectomy (7.9%, n = 7/89), cranioplasty (3.6%, n = 4/112), bypass surgery (1.7%, n = 1/60), and epidural hematoma evacuation (1.6%, n = 1/64). After spinal surgery, POH was observed in 1.1% of cervical and 2.1% of thoracolumbar operations, whereas 46.7% were multilevel procedures. 64.3% of patients with POH and 84.6% of patients undergoing craniotomy had postoperative hypertension (systolic blood pressure >160 mm Hg or lower if indicated). Poor outcome (Glasgow Outcome Scale score 1-3), whereas death at 6 months after craniotomy was detected in 40.9% and 21.7%. respectively, of patients with POH who underwent craniotomy.

CONCLUSIONS

POH after neurosurgery was rare in this series but was associated with poor outcome. Identification of risk factors of bleeding, and avoiding them, if possible, might decrease the incidence of POH.

Is postoperative imaging mandatory after meningioma removal? Results of a prospective study

Background

Routine postoperative imaging (PI) following surgery for intracranial meningiomas is common practice in most neurosurgical departments. The purpose of this study was to determine the role of routine PI and its impact on clinical decision making after resection of meningioma.

Methods

Patient and tumor characteristics, details of radiographic scans, symptoms and alteration of treatment courses were prospectively collected for patients undergoing removal of a supratentorial meningioma of the convexity, falx, tentorium, or lateral sphenoid wing at the authors’ institution between January 1st, 2010 and March 31st, 2012. Patients with infratentorial manifestations or meningiomas of the skull base known to be surgically difficult (e.g. olfactory groove, petroclival, medial sphenoid wing) were not included. Maximum tumor diameter was divided into groups of < 3cm (small), 3 to 6 cm (medium), and > 6 cm (large).

Results

206 patients with meningiomas were operated between January 2010 and March 2012. Of these, 113 patients met the inclusion criteria and were analyzed in this study. 83 patients (73.5%) did not present new neurological deficits, whereas 30 patients (26.5%) became clinically symptomatic. Symptomatic patients had a change in treatment after PI in 21 cases (70%), while PI was without consequence in 9 patients (30%). PI did not result in a change of treatment in all asymptomatic patients (p<0.001) irrespective of tumor size (p<0.001) or localization (p<0.001).

Conclusions

PI is mandatory for clinically symptomatic patients but it is safe to waive it in clinically asymptomatic patients, even if the meningioma was large in size.

Impact of preoperative laboratory investigation and blood cross-match on clinical management of pediatric neurosurgical patients

PURPOSE

Studies in the adult literature suggest that preoperative laboratory investigations and cross-match are performed unnecessarily and rarely lead to changes in clinical management. The purposes of this study were the following: (1) to explore whether preoperative laboratory investigations in neurosurgical children alter clinical management and (2) to determine the utilization of cross-matched blood perioperatively in elective pediatric neurosurgical cases.

METHODS

We reviewed pediatric patient charts for elective neurosurgery procedures (June 2010-June 2014) at out institution. Variables collected include preoperative complete blood count (CBC), electrolytes, coagulation, group and screen, and cross-match. A goal of the review was to identify instances of altered clinical management, as a consequence of preoperative blood work. The number of cross-matched blood units transfused perioperatively was also determined.

RESULTS

Four hundred seventy-seven electively scheduled pediatric neurosurgical patients were reviewed. Preoperative CBC was done on 294, and 39.8 % had at least one laboratory abnormality. Electrolytes (84 patients) and coagulation panels (241 patients) were abnormal in 23.8 and 24.5 %, respectively. The preoperative investigations led to a change in clinical management in three patients, two of which were associated with significant past medical history. Group and screen test was performed in 62.5 % of patients and 57.9 % had their blood cross-matched. Perioperative blood transfusions (71 % of these patients were under 3 years of age) were received by 3.6 % of patients (17/477). The cross-match to transfusion ratio was 16.

CONCLUSION

This study suggests that the results of preoperative laboratory exams have limited value, apart from cases with oncology and complex preexisting conditions. Additionally, cross-matching might be excessively conducted in elective pediatric neurosurgical cases.

Fibrinogen but not factor XIII deficiency is associated with bleeding after craniotomy

BACKGROUND

Postoperative haemorrhage in neurosurgery is associated with significant morbidity and mortality. There is controversy whether or not factor XIII (FXIII) deficiency leads to bleeding complications after craniotomy. Decreased fibrinogen levels have been associated with an increased incidence of bleeding complications in cardiac and orthopaedic surgery. The aim of this study was to assess perioperative fibrinogen and FXIII levels in patients undergoing elective intracranial surgery with and without severe bleeding events.

METHODS

Perioperative FXIII and fibrinogen levels were prospectively assessed in 290 patients undergoing elective craniotomy. Patients were divided into two groups according to the presence or absence of severe bleeding requiring surgical revision. Coagulation test results of these groups were compared using Student's t-test.

RESULTS

The incidence of postoperative severe bleeding was 2.4%. No differences in FXIII levels were observed, but postoperative fibrinogen levels were significantly lower in patients suffering from postoperative haematoma compared with those without postoperative intracranial bleeding complications [237 mg dl(-1) (standard deviation, SD 86) vs 170 mg dl(-1) (SD 35), P=0.03]. The odds ratio for postoperative haematoma in patients with a postoperative fibrinogen level below 200 mg dl(-1) was 10.02 (confidence interval: 1.19-84.40, P=0.03).

CONCLUSIONS

This study emphasizes the role of fibrinogen as potentially modifiable risk factor for perioperative bleeding in intracranial surgery. Future randomized controlled trials will be essential to identify patients who might benefit from fibrinogen substitution during neurosurgical procedures.

Routine preoperative blood testing in pediatric neurosurgery

OBJECT

The frequency with which routine preoperative blood test results predict perioperative or postoperative complications is insignificant. The unnecessary ordering of routine tests increases the financial costs and patients' distress. The authors evaluated the effects of routine preoperative testing on patient management and the overall financial costs.

METHODS

The authors retrospectively reviewed the medical records and laboratory data for 355 children admitted to the neurosurgical department for elective procedures over a 5-year period (January 2008-December 2012). They excluded all patients admitted for imaging or surgical procedures requiring local anesthesia, and they recorded the results of preoperative and previous (up to 6 months before surgery) blood tests and any abnormalities noted.

RESULTS

As a result of the 3489 blood tests ordered preoperatively for 328 (94.6%) of the 355 patients, 29 abnormalities (9%) were detected. Most of these abnormal values were near the reference range, and none significantly affected the progression of scheduled procedures. For only 1 patient (0.28%) was the procedure cancelled because of an abnormality (preoperative partial thromboplastin time), which further testing showed to be a false-positive result. The cost of these tests over 5 years was 5205-10,410 euros ($6766-$13,533 US).

CONCLUSIONS

Preoperative tests should be selectively requested on the basis of clinical indication.

Evaluating compliance with institutional preoperative testing guidelines for minimal-risk patients undergoing elective surgery

Background. Few investigations preoperatively are important for low-risk patients. This study was designed to determine the level of compliance with preoperative investigation guidelines for ASA I patients undergoing elective surgery. Secondary objectives included the following: to identify common inappropriate investigations, to evaluate the impact of abnormal testing on patient management, to determine factors affecting noncompliant tests, and to estimate unnecessary expenditure. Methods. This retrospective study was conducted on adult patients over a one-year period. The institute's guidelines recommend tests according to the patients' age groups: a complete blood count (CBC) for those patients aged 18–45; CBC, chest radiograph (CXR) and electrocardiography (ECG) for those aged 46–60; and CBC, CXR, ECG, electrolytes, blood glucose, blood urea nitrogen (BUN), and creatinine (Cr) for patients aged 61–65. Results. The medical records of 1,496 patients were reviewed. Compliant testing was found in only 12.1% (95% CI, 10.5–13.9). BUN and Cr testings were the most frequently overprescribed tests. Overinvestigations tended to be performed on major surgery and younger patients. Overall, overinvestigation incurred an estimated cost of US 200,000 dollars during the study period. Conclusions. The need to utilize the institution's preoperative guidelines should be emphasized in order to decrease unnecessary testing and the consequential financial burden.