A comparative study of treatments for chronic subdural hematoma: burr hole drainage versus burr hole drainage with irrigation

Irrigation versus no irrigation in the treatment of chronic subdural hematoma: An updated systematic review and meta-analysis of 1581 patients

Burr hole craniotomy is a common technique employed in the treatment of chronic subdural hematoma. However, its effectiveness and the occurrence of additional complications with various irrigation techniques utilized during the surgery remain unclear. The paper aims to compare the effectiveness and safety of burr hole craniotomy with and without irrigation in the treatment of chronic subdural hematoma. We conducted a systematic review by searching PubMed, Cochrane Library, Scopus, Ovid, and Web of Science for comparative studies that fit the eligibility criteria. All studies up to January 2023 were included, and the two groups were compared based on five primary outcomes using Review Manager Software. Data reported as odds ratio (OR) or risk ratio (RR) and 95% confidence interval (CI). A p-value of less than 0.05 was considered statistically significant. Our analysis included 12 studies with a total of 1581 patients. There was no significant difference between the two techniques in terms of recurrence rate (OR = 0.94; 95% CI [0.55, 1.06], p-value = 0.81) and mortality rate (RR = 1.05, 95% CI [0.46, 2.40], p-value = 0.91). Similarly, there was no significant difference in postoperative infection (RR = 1.15, 95% CI [0.16, 8.05], p-value = 0.89) or postoperative pneumocephalus (RR = 2.56, 95% CI [0.95, 6.89], p-value = 0.06). The burr hole drainage with irrigation technique was insignificantly associated with a higher risk of postoperative hemorrhagic complication (RR = 2.23, 95% CI [0.94, 5.29], p-value = 0.07); however, sensitivity analysis showed significant association based on the results of two studies (RR = 4.6, 95% CI [1.23, 17.25], p-value = 0.024). The two techniques showed comparable recurrence, mortality rate, postoperative infection, and postoperative pneumocephalus results. However, irrigation in burr hole craniotomy could possibly have a higher risk of postoperative hemorrhage compared with no irrigation, as observed during sensitivity analysis, which requires to be confirmed by other studies. Further research and randomized controlled trials are required to understand these observations better and their applicability in clinical practice.

Intraoperative Irrigation and Risk of Chronic Subdural Hematoma Recurrence

BACKGROUND AND OBJECTIVES

In most neurosurgical centers, irrigation is an essential part of the surgical procedure for chronic subdural hematoma (CSDH). However, it is unknown whether the volume of irrigation fluid affects the risk of CSDH recurrence. This study aimed to investigate a potential association between the volume of irrigation fluid used during burr hole evacuation of CSDH and the risk of CSDH recurrence.

METHODS

This study is a subanalysis of 2 randomized trials (Drain Time & Drain Time 2) designed to investigate the effect of drainage duration on the recurrence of CSDH. Intraoperative irrigation volume was measured, and patients were followed for 90 days for recurrent CSDH.

RESULTS

A total of 525 patients with CSDH were included. There was no significant difference in the volume of irrigation fluid used between patients with recurrence (mean = 938 mL, SD = ±552) and without recurrence (mean = 852 mL, SD = ±454) ( P -value = .15). Patients with recurrent CSDH had larger primary CSDH volumes (mean = 134 cm 3 , SD = ±69) than patients without recurrence (mean = 119 cm 3 , SD = ±58) ( P = .04). Multiple logistic regression analysis revealed no association between irrigation volume and recurrence, also when stratified for hematoma size.

CONCLUSION

There was no significant association between irrigation volume and recurrent CSDH within 90 days in patients undergoing burr hole surgery for CSDH.

Retrospective Analysis of Risk Factors for Recurrence of Chronic Subdural Haematoma after Surgery

(1) Background: In this study, epidemiological, clinical, therapeutical, and haemostaseological variables were investigated regarding their correlation with the recurrence of chronic subdural haematomas to assess the risk of recurrence more reliably in everyday clinical practice. (2) Methods: In our retrospective study, the electronic records of 90 patients who underwent surgery for a chronic subdural haematoma at our institute between 1 January 2017 and 31 May 2021 were analysed regarding previously defined variables. (3) Results: In the patient collective, 33.33% of the 90 patients experienced a recurrence requiring treatment. The occurrence of a recurrence was not statistically significantly related to age, gender, known alcohol abuse, a specific location, extension over one or both hemispheres, the surgical method, or anticoagulant medication. However, the recurrence was statistically significantly related to haematoma width (p = 0.000007), septation (p = 0.005), and the existence of a coagulation disorder not treated with medication (p = 0.04). (4) Conclusions: In our study, the width of the haematoma, septation, and coagulation disorders not treated with medication were documented as risk factors for the occurrence of a chronic subdural haematoma. Identifying of these risk factors could help in adapting individual therapeutic concepts for chronic subdural haematomas.

Efficacy of intraoperative irrigation with artificial cerebrospinal fluid in chronic subdural hematoma surgery: study protocol for a multicenter randomized controlled trial

BACKGROUND

The surgical techniques for treatment of chronic subdural hematoma (CSDH), a common neurosurgical condition, have been discussed in a lot of clinical literature. However, the recurrence proportion after CSDH surgery remains high, ranging from 10 to 20%. The standard surgical procedure for CSDH involves a craniostomy to evacuate the hematoma, but irrigating the hematoma cavity during the procedure is debatable. The authors hypothesized that the choice of irrigation fluid might be a key factor affecting the outcomes of surgery. This multicenter randomized controlled trial aims to investigate whether intraoperative irrigation using artificial cerebrospinal fluid (ACF) followed by the placement of a subdural drain would yield superior results compared to the placement of a subdural drain alone for CSDH.

METHODS

The study will be conducted across 19 neurosurgical departments in Japan. The 1186 eligible patients will be randomly allocated to two groups: irrigation using ACF or not. In either group, a subdural drain is to be placed for at least 12 h postoperatively. Similar to what was done in previous studies, we set the proportion of patients that meet the criteria for ipsilateral reoperation at 7% in the irrigation group and 12% in the non-irrigation group. The primary endpoint is the proportion of patients who meet the criteria for ipsilateral reoperation within 6 months of surgery (clinical worsening of symptoms and increased hematoma on imaging compared with the postoperative state). The secondary endpoints are the proportion of reoperations within 6 months, the proportion being stratified by preoperative hematoma architecture by computed tomography (CT) scan, neurological symptoms, patient condition, mortality at 6 months, complications associated with surgery, length of hospital stay from surgery to discharge, and time of the surgical procedure.

DISCUSSION

We present the study protocol for a multicenter randomized controlled trial to investigate our hypothesis that intraoperative irrigation with ACF reduces the recurrence proportion after the removal of chronic subdural hematomas compared with no irrigation.

TRIAL REGISTRATION

ClinicalTrials.gov jRCT1041220124. Registered on January 13, 2023.

Subdural open drains as an effective and low-cost modality for the treatment of chronic subdural hematomas

PURPOSE

We present a series that describes the presenting features and clinical outcomes in patients with CSDH treated with a standardised technique and an open-drain placement.

METHODS

We reviewed the medical records of 155 consecutive patients at a single centre who underwent CSDH evacuation by placing burr holes, accompanied by intraoperative irrigation and a subdural Penrose drain between 2014 and 2018.

RESULTS

The mean age was 65.9 years, 81.9% were males. The most common clinical characteristics were an altered mental state (21.9%) and headache (12.9%). It was necessary to perform a second surgical intervention due to the evidence in the postoperative tomography of a residual hematoma in 10.3% of the cases; there were 2 cases of recurrence in 6 months (1.3%). Pneumonia (6.5%) and seizures (5.8%) were the most frequent medical complications. Intracranial infections accounted for 1.9%, and the mortality rate was 6.4% of cases.

CONCLUSIONS

We provided our experience with a low-cost and less-commonly used technique in the management of CSDH. This technique showed similar recurrence, mortality and intracranial infection rates to those reported in the literature for closed drainage systems. Additional studies will be required to assess this technique.

A prospective randomized controlled trial of the effect of the number of burr hole on chronic subdural hematoma recurrence: An institutional experience

OBJECTIVE

The purpose of this study was to compare the effect of single burr hole (SBH) versus double burr hole (DBH) drainage on the recurrence rate of chronic subdural hematoma (CSDH).

METHOD

Forty-four patients undergoing burr hole craniostomy (BHC) between July 2022 and December 2022 were enrolled in a randomized clinical trial (RCT) comparing SBH to DBH surgeries. The primary endpoint of this study was the recurrence rate of CSDH. Radiological characteristics such as midline shift, thickness, volume, density, type of hematoma, brain atrophy and so on were secondary endpoints.

RESULTS

Forty-four patients participated in this study. Twenty-two hematomas underwent SBH craniostomy, and the other 22 had DBH craniostomy. The mean age in the SBH and DBH groups were 68.59 ± 7.94 and 69.54 ± 10.58, respectively. In each group, the proportion of males (SBH=16; DBH=15) was higher than that of females (SBH=6; DBH=7). The mean surgery time in the SBH group was significantly less than in the DBH group (p = 0.001). However, the two groups had no statistically significant difference in the CSDH recurrence rate (p = 0.312).

CONCLUSION

Our findings showed that SBH craniostomy is equally effective as DBH craniostomy at draining hematomas and does not increase the recurrence rate. Contrarily, the SBH craniostomy had a shorter surgical duration than the DBH craniostomy. As a result, we recommend SBH surgeries for all patients, with emphasis on the elderly and those with severe comorbidities, as well as in situations with few surgical facilities and a high patient admission rate.

Half-Saline Versus Normal-Saline as Irrigation Solutions in Burr Hole Craniostomy to Treat Chronic Subdural Hematomata: A Randomized Clinical Trial

OBJECTIVE

This study aimed to evaluate the efficacy and safety of half-saline (HS) serum as an irrigation solution in chronic subdural hematoma (CSDH) surgery using the burr hole craniostomy (BHC) technique.

METHODS

This randomized clinical trial was conducted in university hospital referral centers from 2020 to 2021. Sixty-three patients with CSDH eligible for BHC were primarily enrolled. Two patients were excluded because of concurrent stroke. Sixty-one patients were randomly allocated into case (HS=30) and control (normal-saline [NS]=31) groups. HS was used to irrigate the hematoma in the case group and NS was used in the control group. The patients were followed-up. Clinical variables including demographic and medical findings, postoperative computed tomography findings, postoperative complications, hospitalization period, recurrence rate, and functional status measured by the Barthel type B index were recorded.

RESULTS

Forty-six of 61 patients were male (75.4%), and the patients' mean age was 65.4±16.9 years, with equal distribution between the 2 groups. Postoperative effusion and postoperative hospital stay duration were significantly lower in the HS group than in the NS group (p=0.002 and 0.033, respectively). The postoperative recurrence within 3 months in both groups was approximately equal (6.6%). In terms of functional outcomes and postoperative complications, HS showed similar results to those of NS.

CONCLUSION

HS as an irrigation fluid in BHC effectively reduced postoperative effusion and hospital stay duration without considerable complications.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials Identifier: IRCT20200608047688N1.

Controversies in the Surgical Treatment of Chronic Subdural Hematoma: A Systematic Scoping Review

Chronic subdural hematoma (cSDH) is one of the most common neurosurgical entities, especially in the elderly population. Diagnosis is usually established via a head computed tomography, while an increasing number of studies are investigating biomarkers to predict the natural history of cSDH, including progression and recurrence. Surgical evacuation remains the mainstay of treatment in the overwhelming majority of cases. Nevertheless, many controversies are associated with the nuances of surgical treatment. We performed a systematic review of the literature between 2010 and 2022, aiming to identify and address the issues in cSDH surgical management where consensus is lacking. The results show ambiguous data in regard to indication, the timing and type of surgery, the duration of drainage, concomitant membranectomy and the need for embolization of the middle meningeal artery. Other aspects of surgical treatment-such as the use of drainage and its location and number of burr holes-seem to have been adequately clarified: the drainage of hematoma is strongly recommended and the outcome is considered as independent of drainage location or the number of burr holes.

Modified Burr-Hole Craniostomy for the Treatment of Chronic Subdural Hematoma in Adults

BACKGROUND

Burr-hole craniostomy (BHC) is considered to be the most effective method for the treatment of chronic subdural hematoma (CSDH), and middle meningeal artery embolization is a new therapy used in clinical practice in recent years to treat CSDH. However, the optimal therapeutic effect of these 2 procedures is still controversial. This study prospectively designed a modified burr-hole craniostomy (mBHC) with drainage to treat CSDH.

METHODS

A total of 101 patients diagnosed with CSDH from January 2019 to April 2020 were prospectively included in this study. They were divided into BHC and mBHC groups. Among them, 40 selected CSDH patients received mBHC treatment. For comparison, 61 CSDH patients who received BHC treatment were used as the control group. Primary outcomes were hematoma recurrence and postoperative complications. Secondary outcomes included midline recovery, hematoma clearance, operation time, and hospital stay. The Chi-square test was used to compare the 6-month follow-up results between the 2 groups.

RESULTS

Among patients treated with mBHC, 39 patients had a good prognosis, and one 87-year-old patient with bilateral hematoma died of postoperative heart failure. Of the patients treated with BHC, 52 patients had good prognoses, and one 53-year-old patient with unilateral hematoma died of postoperative acute intracranial bleeding. During the 6-month follow-up period, no relapse occurred in the patients treated with mBHC, whereas 8 (13%) of the patients treated with BHC relapsed. There was a significant difference in the recurrence rate between the 2 groups (P < 0.05). In addition, midline recovery, hematoma clearance rate, operation time, and complications were found to be significantly different statistically (P < 0.05), and other characteristics of operation and outcome were not significantly different (P > 0.05) between the 2 groups.

CONCLUSIONS

Modified burr-hole craniostomy has a positive therapeutic effect on patients with CSDH and is more effective than conventional BHC therapy.

Net Drainage as a Novel Metric for Irrigating Drainage Systems in Chronic Subdural Hematoma Management: A Case Report

BACKGROUND AND IMPORTANCE

Chronic subdural hematoma (cSDH) is a common neurosurgical pathology with a projected increase in prevalence as the elderly population grows. Traditional treatment for cSDH involves burr hole drainage or craniotomy with or without a subdural drain. This case describes a novel irrigation and drainage protocol using IRRAflow dual-lumen catheter system that utilizes early irrigation and measurement of the net fluid output to improve postoperative outcomes.

CLINICAL PRESENTATION

A 75-yr-old male presented to the emergency department with 2 wk of progressive dizziness, headache, confusion, and left-sided weakness over the past week. Computed tomography (CT) of the head showed 25-mm-thick, right-sided cSDH with 7 mm of right-to-left midline shift. The patient was taken to the operating room for right-sided craniotomy for subdural hematoma evacuation with placement of IRRAflow irrigating drain in the subdural space. The IRRAflow drain irrigated at 100 cc/h for 23 h with net output consistently greater than irrigation rate. Head CT the following day showed a progressive decrease in subdural collection. The patient was discharged on postoperative day 2 and had complete resolution of his neurological symptoms by postoperative day 11.

CONCLUSION

As cSDHs become more prevalent in the aging population, development of improved management strategies is imperative. This report describes the use of an IRRAflow dual-lumen catheter with a novel protocol consisting of a high rate of irrigation but net fluid output, which led to rapid recovery and resolution of neurological deficits in a patient with a cSDH.

Minimally Invasive Approach to Subdural Hematoma Treatment Using IRRAflow Catheter and Middle Meningeal Artery Embolization

Chronic subdural hematoma (cSDH) is a common neurosurgical pathology that usually occurs in the seventh decade of life. Patients can present with mental status changes, focal neurologic deficits, seizures, headaches, or may be asymptomatic. Recurrence is common. In order to address this problem with the treatment of cSDH, many studies exist that compare the effectiveness of various treatment modalities. Two recently developed treatment options of cSDH include middle meningeal artery (MMA) embolization and use of self-irrigating catheter systems. To our knowledge there have been no reported cases of combining the use of these new treatments. What follows is a case report of a 72-year-old patient with recurrent cSDH following MMA embolization who underwent minimally invasive surgical drainage of his hematoma using an IRRAflow catheter (IRRAS, San Diego, CA, USA).

Surgical Management of Trauma-Related Intracranial Hemorrhage-a Review

PURPOSE OF REVIEW

The surgical management of trauma-related intracranial hemorrhage is characterized by marked heterogeneity. Large prospective randomized trials have generally been prohibited by the ubiquity of concordant pathology, diversity of trauma systems, and paucity of clinical equipoise among providers.

RECENT FINDINGS

To date, the results of retrospective studies and surgeon preference have driven the indications, modality, extent, and timing of surgical intervention in the global neurosurgical community. With advances in our understanding of the pathophysiology of hemorrhagic TBI and the advent of novel surgical techniques, a reevaluation of surgical indication, timing, and approach is warranted. In this way, we can work to optimize surgical outcomes, achieving maximal functional recovery while minimizing surgical morbidity.

Finnish study of intraoperative irrigation versus drain alone after evacuation of chronic subdural haematoma (FINISH): a study protocol for a multicentre randomised controlled trial

INTRODUCTION

Chronic subdural haematomas (CSDHs) are one of the most common neurosurgical conditions. The goal of surgery is to alleviate symptoms and minimise the risk of symptomatic recurrences. In the past, reoperation rates as high as 20%-30% were described for CSDH recurrences. However, following the introduction of subdural drainage, reoperation rates dropped to approximately 10%. The standard surgical technique includes burr-hole craniostomy, followed by intraoperative irrigation and placement of subdural drainage. Yet, the role of intraoperative irrigation has not been established. If there is no difference in recurrence rates between intraoperative irrigation and no irrigation, CSDH surgery could be carried out faster and more safely by omitting the step of irrigation. The aim of this multicentre randomised controlled trial is to study whether no intraoperative irrigation and subdural drainage results in non-inferior outcome compared with intraoperative irrigation and subdural drainage following burr-hole craniostomy of CSDH.

METHODS AND ANALYSIS

This is a prospective, randomised, controlled, parallel group, non-inferiority multicentre trial comparing single burr-hole evacuation of CSDH with intraoperative irrigation and evacuation of CSDH without irrigation. In both groups, a passive subdural drain is used for 48 hours as a standard of treatment. The primary outcome is symptomatic CSDH recurrence requiring reoperation within 6 months. The predefined non-inferiority margin for the primary outcome is 7.5%. To achieve a 2.5% level of significance and 80% power, we will randomise 270 patients per group. Secondary outcomes include modified Rankin Scale, rate of mortality, duration of operation, length of hospital stay, adverse events and change in volume of CSDH.

ETHICS AND DISSEMINATION

The study was approved by the institutional review board of the Helsinki and Uusimaa Hospital District (HUS/3035/2019 §238) and duly registered at ClinicalTrials.gov. We will disseminate the findings of this study through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT04203550.

Burr hole drainage without irrigation for chronic subdural hematoma

Background:

Chronic subdural hematoma (CSDH) is one of the most common neurosurgical conditions, with different strategies for treatment. Most recent trials favor the use of drainage to reduce the recurrence rate. However, few reports have discussed the efficacy of burr hole drainage without irrigation for treating CSDH. This study aimed to examine the efficacy of burr hole drainage without irrigation in a series of 385 symptomatic CSDH lesions.

Methods:

This retrospective study included a series of 385 symptomatic CSDH lesions in 309 patients, who underwent burr hole drainage without irrigation, between September 2009 and August 2017 at the Department of Neurosurgery, Yao Tokushukai General Hospital, Japan. The risk of recurrence was evaluated based on the patients’ age, sex, preoperative magnetic resonance imaging (MRI) findings, preoperative anticoagulants, hematoma drainage rate, and bilaterality.

Results:

Of the 385 lesions, 41 cases (16 with inadequate follow-up periods and 25 with contraindications for MRI) were excluded from the analysis. The overall recurrence rate in the index study was 4.9% (17/344 lesions). The effects of the preoperative hematoma volume and nonhyperintensity on T1-weighted imaging on the recurrence rate were significant.

Conclusion:

Our findings indicated that burr hole drainage without irrigation is a good surgical modality in patients with CSDH, and preoperative MRI findings can evaluate the risk of recurrence.

Rescue Craniectomy with Subsequent Cranioplasty for Recurrent Symptomatic Subdural Hematoma in Elderly Patients

OBJECTIVE

Recurrent subdural hematoma (SDH) is commonly encountered in clinical practice. Multiple surgical techniques have been reported for management of recurrent SDH with variable success and complication rates. We report an alternative technique to halt SDH reaccumulation in elderly patients with multiple recurrences despite multiple surgical evacuations via rescue craniectomy and subsequent cranioplasty.

METHODS

We retrospectively identified all symptomatic recurrent SDHs in elderly patients (≥60 years old) who were surgically managed with rescue craniectomy with subsequent cranioplasty from November 2004 to January 2018. Patients' demographics and radiologic and surgical variables were recorded and analyzed.

RESULTS

Of 287 patients who received surgical treatment for SDH, 19 patients (6.6%) underwent SDH evacuation with rescue craniectomy and subsequent cranioplasty were included in the study. The median age of the cohort was 73 years (interquartile range: 62-78 years), with 13 men and 6 women. Trauma was the cause of SDH in most cases. Five patients had acute SDH, 4 patients had subacute SDH, and 10 patients had chronic SDH. Fourteen patients had only 1 recurrence of SDH requiring surgical re-evacuation, and 5 had 2 recurrences. Median interval between craniectomy and cranioplasty was 64.5 days (interquartile range: 15-123.3 days). Four complications were encountered. After cranioplasty, 15 patients had no further hemorrhage or recurrence and 4 patients had stable subdural collection during an average follow-up of 38.2 ± 46.9 months.

CONCLUSIONS

Rescue craniectomy followed by cranioplasty is a safe and effective salvage technique for the management of symptomatic recurrent SDH in elderly patients.

Middle Meningeal Artery Embolization as Treatment for Chronic Subdural Hematoma: A Case Series

BACKGROUND

Traditional treatment for symptomatic subdural hematoma (SDH) has been surgical evacuation, but recurrence rates are high and patients often harbor complex medical comorbidities. Growth and recurrence is thought to be due to the highly friable nature of the vascularized membrane that forms after initial injury. There have been reported cases of middle meningeal artery (MMA) embolization for treatment of recurrent SDH after surgical evacuation with the goal of eliminating the arterial supply to this vascularized membrane.

OBJECTIVE

To present the first known case series of MMA embolization as upfront treatment for symptomatic chronic SDHs that have failed conservative management in lieu of surgical evacuation.

METHODS

Five patients with symptomatic chronic SDHs underwent MMA embolization using PVA microparticles at our institution. Size of SDH was recorded in maximum diameter and total volume.

RESULTS

Four patients underwent unilateral and 1 underwent bilateral MMA embolization successfully. All cases had significant reduction in total volume of SDH at longest follow-up scan: 81.4 to 13.8 cc (7 wk), 48.5 to 8.7 cc (3 wk), 31.7 and 88 to 0 and 17 cc (14 wk, bilateral), 79.3 to 24.2 cc (8 wk), and 53.5 to 0 cc (6 wk). All patients had symptomatic relief with no complications. Histologic analysis of the chronic SDH membrane in a separate patient that required surgery revealed rich neovascularization with many capillaries and few small arterioles.

CONCLUSION

MMA embolization could present a minimally invasive and low-risk initial treatment alternative to surgery for symptomatic chronic SDH when clinically appropriate.

Burr-Hole Evacuation of Chronic Subdural Hematoma: Biophysically and Evidence-Based Technique Improvement

Chronic subdural hematoma (CSDH) is one of the most common neurosurgical conditions. Despite ongoing efforts, recurrence and reoperation rates after surgical treatment remain high. We synthesize scientific evidence on the treatment of CSDH with biophysical principles and then propose a simple and effective surgical technique aiming to reduce the recurrence rate. Under local anesthesia, one burr hole is placed in the area above the maximum hematoma thickness. One drain is inserted into the dorsal direction to the deepest point of the hematoma cavity, and a second drain is inserted frontally into the highest point. Next, saline is gently instilled to the dorsal drain to eliminate air from the hematoma cavity through the frontal drain. Once saline has filled the frontal drain, the frontal drain is removed. The dorsal drain is left in situ for 48 h, and the pressure within the cavity may be adapted hydrostatically. We implemented evidence-based conclusions of previous studies and modified the classical burr-hole technique to reduce the recurrence rate. As a result, we developed a straightforward surgical procedure that is possible to perform under local anesthesia, suitable for everyday practice in rural and remote areas while working with limited resources. The novelty of this technique is in the purposeful reduction of postoperative pneumocephalus, a known independent factor of recurrence. Subdural air is eliminated during surgery using a two-drain system. Safety and efficacy of the technique need to be evaluated in future clinical trials.

Risk Factors for Recurrence of Chronic Subdural Hematoma: A Single Center Experience

OBJECTIVE

Chronic subdural hematoma (CSDH) is a common form of intracranial hemorrhage with a substantial recurrence rate. We aimed to investigate the predictive factors for the postsurgical recurrence of CSDH.

METHODS

We retrospectively reviewed the medical records of patients with CSDH who underwent surgery in West China Hospital between January 2012 and June 2018. Univariate and multivariate analyses were performed to identify the relationships between recurrence of CSDH and factors such as age, sex, history of injury, Markwalder grading, computed tomography findings, surgical methods, and outcomes.

RESULTS

A total of 328 patients (281 men and 47 women) aged 22-93 years (mean age, 65.14 ± 13.76 years) were included. Computed tomography findings at admission showed mixed density hematoma in 136 patients, isodensity hematoma in 140, high-density hematoma in 34, and low-density hematoma in 18. The mortality and recurrence rate were 0.30% (1 of 328) and 2.44% (8 of 328), respectively. Six months postoperatively, 327 patients had Markwalder grade 0. Hematoma recurred in 8 patients of which 7 were mixed density hematoma and 1 was isodensity hematoma. Six patients who underwent craniotomy had thickened inner neomembrane that was resected. Univariate and multivariate analyses found mixed density hematoma to be an independent risk factor for the recurrence of CSDH.

CONCLUSIONS

Burr hole craniostomy with irrigation and closed-system drainage is effective for the surgical treatment of CSDH. Mixed density hematoma is an independent predictor for the recurrence of CSDH. Presence of thick inner neomembrane might be the primary cause of CSDH recurrence.

Single versus double burr-hole drainage for chronic subdural hematoma: A study of relevant prognostic factors conducted in Pakistan

Objective:

To compare the efficacy of single versus double burr-hole for drainage of chronic subdural hematoma, keeping in consideration pertinent demographic, pre and postoperative associations.

Methods:

A prospective cohort study carried out in Combined Military Hospital, Multan, (December 2016-August 2018), on adults with diagnosed chronic subdural hematoma (CSDH); being segregated by randomized control trial, non-probability purposive sampling into Group-A and Group-B (who underwent single and double burr-holes for CSDH-drainage respectively). Utilizing SPSS-21, data expressed as frequencies/percentages and mean± standard deviation (SD) and cross-tabulated; p-value <0.05 was taken as significant.

Results:

Age and GCS scores were 62±13.694 (range 38-94) and 11.00±3.350 (range 3-15) respectively, males being 40(66.7). Post-operative fatality was Nil, while 8(13.3%) and 14(23.3%) had post-operative seizures and recurrence of hematoma respectively. There was no significant association between type of burr-hole and hospital stay (p 0-884), seizures (p 0.448) or recurrence (p 0.542). Hospital stay (p<0.000) and seizures (p-0.005) were inversely proportional to GCS scores on presentation. Recurrence rates were not affected by age (p-0 .175) or gender (p-0 .281).

Conclusion:

There was no significant difference between outcomes of single and double burr-hole surgeries; the former must be preferred because of lesser iatrogenic trauma. GCS-score on presentation was validated as a negative association to anticipate post-operative outcomes.

Recurrence Rate of Chronic Subdural Hematoma after Evacuating It by Two Large Burr Holes, Irrigation, and Subgaleal Low-Pressure Suction Drainage

Background:

There are no current standard operative steps for chronic subdural hematoma (CSDH). The aim of this study was to detect the recurrence rate after drainage of a unilateral diffuse CSDH by combining certain operative steps.

Materials and Methods:

This is a descriptive, retrospective cohort study that included 47 consecutive adult patients who underwent evacuation of a unilateral diffuse CSDH by two large burr holes (≥2 cm in diameter) and irrigation of the subdural space by warm saline, followed by placement of a subgaleal Redivac drain under low-pressure suction in our university hospital from August 2012 to August 2016. There were 29 men and 18 women with a mean age of 69.1 years.

Results:

All the operations were uneventful. All the patients had adequate drainage of their subdural hematomas, and all patients were discharged alert and oriented. No incidence of recurrence within 12 months after surgery.

Conclusion:

This study demonstrated that surgical management of a unilateral diffuse CSDH in adult patients by two large burr holes, irrigation, and a subgaleal Redivac low-pressure suction drainage was effective and associated with no recurrence.

Factors predicting reoperation of chronic subdural hematoma following primary surgical evacuation

OBJECTIVEChronic subdural hematoma (CSDH) is commonly encountered in neurosurgical practice. However, surgical evacuation remains complicated by a high rate of reoperation. The optimal surgical approach to reduce the reoperation rate has not been determined. In the current study, the authors evaluated the prognostic value of clinical and radiographic factors to predict reoperation in the context of CSDH.METHODSA retrospective review of 325 CSDH patients admitted to an academic medical center in the United States, between 2006 and 2016, was performed. Clinical and radiographic factors predictive of the need for CSDH reoperation were identified on univariable and multivariable analyses.RESULTSUnivariable analysis showed that warfarin use, clopidogrel use, mixed hypo- and isointensity on T1-weighted MRI, greater preoperative midline shift, larger hematoma/fluid residual on first postoperative day CT, lesser decrease in hematoma size after surgery, use of monitored anesthesia care (MAC), and lack of intraoperative irrigation correlated with a significantly higher rate of reoperation. Multivariable analysis, however, showed that only the presence of loculation, clopidogrel or warfarin use, and percent of hematoma change after surgery significantly predicted the need for reoperation. Our results showed that 0% (no reduction), 50%, and 100% hematoma maximum thickness change (complete resolution of hematoma after surgery) were associated with a 41%, 6%, and < 1% rate of reoperation, respectively. The use of drains, either large diameter or small caliber, did not have any effect on the likelihood of reoperation.CONCLUSIONSAmong many factors, clopidogrel or warfarin use, hematoma loculation on preoperative CT, and the amount of hematoma evacuation on the first postoperative CT were the strongest predictors of reoperation.

Burr-Hole Craniostomy for Chronic Subdural Hematomas by General Surgeons in Rural Kenya

INTRODUCTION

Chronic subdural hematoma (cSDH) is a common condition that causes significant morbidity and mortality. In rural sub-Saharan Africa, there are very few neurosurgeons. Yet, cSDH is treatable by relatively simple surgical intervention with potential for rapid clinical improvement.

METHODS

We conducted a retrospective chart review of all patients with cSDH who underwent burr-hole trephination at Tenwek Hospital, Kenya, between July 2014 and July 2016. We extracted and compared the clinical presentation, risk factors, operative details, and outcomes.

RESULTS

A total of 119 patients were identified with a mean age of 61.3 years. The majority were men (80%). The main predisposing factors were trauma (54.6%) and alcohol intake (34.4%). Patients were generally managed with two burr-holes, irrigation, and a subdural drain, remaining for a median of 2 days. Operations were assisted by general surgery residents under direct supervision of senior residents (46), general surgeons (65), and neurosurgeons (8). Complications included recurrence (5.2%), subdural empyema (2.5%), postoperative seizures (3.4%), and mortality (6.7%). Improvement of symptoms was noted in 91% of all patients.

CONCLUSION

Operative management of cSDH can be safely performed in rural facilities by general surgeons familiar with the procedure and with the institutional resources. The majority of patients had satisfactory outcomes.

Determining if Cerebrospinal Fluid Prevents Recurrence of Chronic Subdural Hematoma: A Multi-Center Prospective Randomized Clinical Trial

Over the decades, the problem of postoperative recurrence of chronic subdural hematoma (CSDH) has not been resolved. The objective of our study was to investigate whether the recurrence rate of CSDH is decreased when artificial cerebrospinal fluid (ACF) is used as irrigation solution for CSDH surgery. The present study was a multi-center, prospective, randomized, open parallel group comparison test of patients enrolled from 10 hospitals in Japan. Eligible patients with CSDH were randomly assigned to undergo burr hole drainage with either normal saline (NS) or ACF irrigation. The primary end-point was postoperative recurrence of ipsilateral CSDH. A total of 402 patients with newly diagnosed CSDH were enrolled during the study period. After applying inclusion and exclusion criteria, and taking into consideration cases lost to follow-up, our final study cohorts consisted of 177 ACF patients and 165 NS patients, representing 85.7% of the initial cohort. The overall recurrence rate was 11.4%, occurring in 39 of the 342 analyzed patients during 90 days of follow-up. Recurrence rates in the ACF and NS groups were 11.9% (21 of 177) and 10.9% (18 of 165), respectively. No significant difference was evident between groups (p = 0.87). In addition, no significant difference in time to recurrence was seen between groups (p = 0.74). No serious adverse effects related to irrigation fluid were seen in either group. Regarding the irrigation fluid for CSDH surgery, no differences in recurrence rate or time to recurrence were seen between the ACF and NS groups. However, ACF offers sufficient safety as irrigation fluid for CSDH.

Burr hole drainage and burr hole drainage with irrigation to treat chronic subdural hematoma: A systematic review and meta-analysis

OBJECTIVE

Numerous studies have investigated different operative procedures for treating chronic subdural hematoma (CSDH); however, the results are controversial. This meta-analysis was performed to evaluate the efficacy of burr hole drainage without irrigation (BHD) and burr hole drainage with irrigation (BHDI) for CSDH.

METHODS

We searched the following electronic databases to identify all studies from their inception to September 2017: Cochrane Library, Science Direct, MEDLINE, EMBASE, Scopus, Google Scholar, the China Biomedical Database (CBM), and the Chinese National Knowledge Infrastructure (CNKI). Randomized clinical trials (RCTs), prospective cohort studies, retrospective observational cohort studies, and case-control studies investigating BHD and BHDI for the treatment of CSDH were included. The Cochrane Collaboration's RevMan 5.3 software was used for meta-analysis.

RESULTS

In total, 7 retrospective cohort studies and 2 RCTs involving 993 participants were included. Comprehensive analysis results of 9 studies indicated that the recurrence of the BHDI was similar to that in BHD (odds ratio [OR] = 1.27, 95% confidence interval [CI] = .61-2.63, P = .53). Moreover, analysis for comparing recurrence in the 2 RCTs was not significantly different (OR = 1.14, 95% CI = .16-8.24, P = .95).In addition, meta-analysis of pneumocephalus (OR = 5.91, 95% CI = .61-56.86, P = .12) and mortality (OR = 0.94, 95% CI 0.14-6.16, P = .95) was not significantly different.

CONCLUSIONS

The results of this meta-analysis demonstrated that procedures with or without irrigation in the treatment of CSDH might have similar effect regarding recurrence and complications; therefore, irrigation might not be necessary. However, well-conducted RCTs and high-quality observational studies are still required to corroborate this issue.

Management of Subdural Hematomas: Part II. Surgical Management of Subdural Hematomas

PURPOSE OF REVIEW

Management of patients with subdural hematomas starts with Emergency Neurological Life Support guidelines. Patients with acute or chronic subdural hematomas (SDHs) associated with rapidly deteriorating neurologic exam, unilaterally or bilaterally dilated nonreactive pupils, and extensor posturing are considered imminently surgical; likewise, SDHs more than 10 mm in size or those associated with more than 5-mm midline shift are deemed operative.

RECENT FINDINGS

While twist drill craniostomy and placement of subdural evacuating vport system (SEPS) are quick, bedside procedures completed under local anesthesia and appropriate for patients with chronic SDH or patients that cannot tolerate anesthesia, these techniques are not optimal for patients with acute SDH or chronic SDH with septations. Burr hole SDH evacuation under conscious sedation or general anesthesia is an analogous technique; however, it requires basic surgical equipment and operating room staff, with a focus on a closed system with burr hole followed by rapid drain placement to avoid introduction of air into the subdural space, or multiple burr holes with extensive irrigation to reduce pneumocephalus and continue SDH evacuation via drain for several days. Acute SDH associated with significant mass effect and cerebral edema requires aggressive decompression via craniotomy with clot evacuation and frequently a craniectomy. Chronic SDHs that fail conservative management and progress clinically or radiographically are addressed with craniotomy with or without membranectomy. Surgical SDH management is variable depending on its characteristics and etiology, patient's functional status, comorbidities, goals of care, institutional preferences, and availability of specialized surgical equipment and adjunct therapies. Rapid access to surgical suites and trained staff to address surgical hemorrhages in a timely manner, with appropriate post-operative care by a specialized team including neurosurgeons and neurointensivists, is of paramount importance for successful patient outcomes. Here, we review various aspects of surgical SDH management.

Burr-Hole Craniostomy with T-Tube Drainage as Surgical Treatment for Chronic Subdural Hematoma

OBJECTIVE

We sought to investigate the effect of burr-hole craniostomy with T-tube drainage to treat chronic subdural hematoma (CSDH).

METHODS

Eighty-seven patients with CSDH who were recruited from January 2012 to June 2017 at the Department of Neurosurgery, The First Affiliated Hospital of Xi'an Medical University, were divided into 2 groups according to the method of drainage: T-tube drainage system (n = 45) and conventional subdural drainage system (n = 42). Retrospective analysis of clinical data and efficacy was performed between the 2 groups.

RESULTS

There were no significant differences in age, preoperative Markwalder grade scale, preoperative hematoma volume, hospitalization days, and discharge Markwalder grade scale between the 2 groups (P > 0.05). The incidence of postoperative complications and hematoma recurrence in the group of patients with T-tube drainage was significantly reduced when compared with conventional subdural drainage systems (P < 0.05).

CONCLUSIONS

Both methods were effective in the treatment of CSDH; however, we found a lower overall surgical complication rate following treatment with burr-hole craniostomy and T-tube drainage. This indicates that it may be a better therapeutic option for management of CSDH.

Chronic Subdural Hematoma in Elderly Patients: Is This Disease Benign?

As the world population becomes progressively older, the overall incidence of chronic subdural hematoma (CSDH) is increasing. Peak age of onset for CSDH has also increased, and recently the 80-year-old level has a peak. Many patients with CSDH have had prior treatment with anticoagulants and antiplatelet drugs, which have an accompanying risk of CSDH. In elderly patients with CSDH, symptoms of cognitive change (memory disturbance, urinary incontinence, and decreased activity) and disturbance of consciousness at admission were more frequent compared to younger patients with CSDH. The literature actually offers conflicting advice regarding CSDH treatment; however, burr hole surgery with drainage under local anesthesia is the most common surgical procedure, even in elderly patients. The recurrence rate of CSDH has not decreased over recent decades, and it has ranged from 0.36-33.3%. Outcomes in patients over 75 years old was significantly worse than for those younger than 75. Moreover, long-term outcomes for elderly patients with CSDH are poor. CSDH in the elderly is no longer a benign disease. In the future, it will be important for us to understand the mechanisms of onset and recurrence of CSDH and to develop more effective medical treatments and noninvasive surgical techniques for elderly patients.

Correlation between Head Trauma and Outcome of Chronic Subdural Hematoma

Objective

Our study examined the prognostic factors involved in the outcome of patients with chronic subdural hematoma (CSDH) who had undergone burr hole drainage procedures, and investigated the association between outcome and traumatic head injury. In addition, we explored factors related to recurrence.

Methods

This study enrolled 238 patients with CSDH who had undergone burr hole drainage. Patients with history of head injury were categorized into the head trauma group and were compared with the no head trauma group. Outcome was considered good when modified Rankin Scale scores improved from admission to discharge and the final follow-up.

Results

Among 238 patients, 127 (53.4%) were included in the head trauma group. One hundred thirty-three (55.9%) patients demonstrated good outcome at discharge, and 171 (71.8%) patients demonstrated good outcome at the final follow-up. None of the factors examined was significantly correlated with good outcome at discharge. However, only history of head injury (p=0.033, odds ratio 0.511, 95% confidence interval 0.277-0.946) was significantly correlated with poor outcome at long-term follow-up. Recurrence occurred in 20 (8.4%) cases in the total cohort and 11 (55%) patients in the head trauma group.

Conclusion

History of head trauma is correlated with poor outcome at long-term follow-up in CSDH patients having undergone burr hole drainage. Therefore, CSDH patients with history of head injury are susceptible to poor outcome, warranting more careful evaluation and treatment after burr hole drainage.

Chronic subdural hematoma

Chronic subdural hematoma (CSDH) is one of the most common neurosurgical conditions. There is lack of uniformity in the treatment of CSDH amongst surgeons in terms of various treatment strategies. Clinical presentation may vary from no symptoms to unconsciousness. CSDH is usually diagnosed by contrast-enhanced computed tomography scan. Magnetic resonance imaging (MRI) scan is more sensitive in the diagnosis of bilateral isodense CSDH, multiple loculations, intrahematoma membranes, fresh bleeding, hemolysis, and the size of capsule. Contrast-enhanced CT or MRI could detect associated primary or metastatic dural diseases. Although definite history of trauma could be obtained in a majority of cases, some cases may be secondary to coagulation defect, intracranial hypotension, use of anticoagulants and antiplatelet drugs, etc., Recurrent bleeding, increased exudates from outer membrane, and cerebrospinal fluid entrapment have been implicated in the enlargement of CSDH. Burr-hole evacuation is the treatment of choice for an uncomplicated CSDH. Most of the recent trials favor the use of drain to reduce recurrence rate. Craniotomy and twist drill craniostomy also play a role in the management. Dural biopsy should be taken, especially in recurrence and thick outer membrane. Nonsurgical management is reserved for asymptomatic or high operative risk patients. The steroids and angiotensin converting enzyme inhibitors may also play a role in the management. Single management strategy is not appropriate for all the cases of CSDH. Better understanding of the nature of the pathology, rational selection of an ideal treatment strategy for an individual patient, and identification of the merits and limitations of different surgical techniques could help in improving the prognosis.

Comparison of the Outcomes and Recurrence with Three Surgical Techniques for Chronic Subdural Hematoma: Single, Double Burr Hole, and Double Burr Hole Drainage with Irrigation

Objective

Chronic subdural hematoma (CSDH), a disease commonly encountered by neurosurgeons, is treated by burr hole drainage (BHD). However, the optimal surgical technique among the three types of BHD has not been determined.

Methods

We conducted a retrospective study on BHD performed on 93 patients who were diagnosed with CSDH. The subjects were divided into three groups based on the surgical technique performed: single BHD without irrigation (Group A, n=31), double BHD without irrigation (Group B, n=32), and double BHD with irrigation (Group C, n=30). The clinical factors, radiological factors and recurrences were compared between the three groups. Moreover, independent factors affecting the recurrence were analyzed.

Results

The change in hematoma thickness was 29.77±7.94%, 49.73±12.87%, and 75.29±4.32% for Group A, B, and C, respectively, while the change in midline shift was 40.81±15.47%, 51.78±10.94%, and 56.16±16.16%, respectively. Thus, Group C showed the most effective for resolution of hematoma and midline shift (p<0.05). Group A, B, and C had 12 cases (38.7%), 8 cases (25.0%), and 3 cases (10.0%) of recurrences, respectively. Group C had a statistically significantly fewer recurrence rate than Group A (p<0.05). Double burr hole, irrigation, and coagulopathy were each identified as independent factors that reduce recurrence (p<0.05).

Conclusion

Among the three techniques, the double BHD with saline irrigation resulted in the fewest recurrences. It is probably the most effective technique for preventing the recurrence of CSDH.

Surgical Treatments for Chronic Subdural Hematomas: A Comprehensive Systematic Review

BACKGROUND

Chronic subdural hematomas (CSDHs) are common neurosurgical conditions among elderly patients.

OBJECTIVE

To perform a detailed critical appraisal of all randomized controlled trials (RCTs) of surgical treatments for chronic subdural hematomas and to quantify their intervention effects.

METHODS

We performed a broad search for all RCTs with no language or date restrictions, asked the authors for missing data, and applied the Cochrane methods.

RESULTS

A total of 24 RCTs involved 1900 patients and 15 comparisons. All outcomes of practical interest were analyzed. Postoperative drainage after burr-hole evacuation reduced the rate of recurrence (risk ratio 0.48, 95% confidence interval 0.34-0.66, P < 0.00001) with no other clear benefits or complications.

CONCLUSIONS

This comprehensive, best evidence-based, quantitative, systematic review indicates that the use of a closed system drainage after burr-hole evacuation reduces the rate of recurrences but has no other significant differences. The findings also suggest that: (1) treatment with twist drills is equivalent to that with burr holes; (2) the postoperative bed header in the elevated position might reduce the length of hospital stay; (3) irrigation of the subdural space with thrombin solution in patients with high risk of recurrence might reduce this risk; and (4) treatment with twist drill followed by a closed system drainage during 48 hours, instead of 96 hours, might reduce general complication rates. Most of the trials suffered from unclear or high risks of bias and many involved small samples, precluding strong and definitive conclusions.

Burr-hole Irrigation with Closed-system Drainage for the Treatment of Chronic Subdural Hematoma: A Meta-analysis

There is controversy among neurosurgeons regarding whether irrigation or drainage is necessary for achieving a lower revision rate for the treatment of chronic subdural hematoma (CSDH) using burr-hole craniostomy (BHC). Therefore, we performed a meta-analysis of all available published reports. Multiple electronic health databases were searched to identify all studies published between 1989 and June 2012 that compared irrigation and drainage. Data were processed by using Review Manager 5.1.6. Effect sizes are expressed as pooled odds ratio (OR) estimates. Due to heterogeneity between studies, we used the random effect of the inverse variance weighted method to perform the meta-analysis. Thirteen published reports were selected for this meta-analysis. The comprehensive results indicated that there were no statistically significant differences in mortality or complication rates between drainage and no drainage (P > 0.05). Additionally, there were no differences in recurrence between irrigation and no irrigation (P > 0.05). However, the difference between drainage and no drainage in recurrence rate reached statistical significance (P < 0.01). The results from this meta-analysis suggest that burr-hole surgery with closed-system drainage can reduce the recurrence of CSDH; however, irrigation is not necessary for every patient.

Recurrence of the Chronic Subdural Hematoma after Burr-Hole Drainage with or without Intraoperative Saline Irrigation

Objective

Although standard method has not been established for the chronic subdural hematoma (CSDH), burr-hole trephination and closed system drainage with or without irrigation has been widely accepted as the treatment of choice. The aim of this study is to analysis the post-operative recurrence rates after burr-hole trephination of the CSDH according to the conduction of irrigation.

Methods

We retrospectively reviewed 184 patients with CSDH who underwent surgical treatment between January 2009 and December 2013. And 152 patients fulfilled the inclusion criteria as follows: 1) CSDH diagnosed on computed tomography (CT), 2) unilateral hematoma, 3) burr-hole trephination with closed system drainage, and 4) follow-up CT for at least 3 months. Those patients were divided into two groups. Group A (n=38) underwent burr-hole trephination without irrigation, and Group B (n=114), burr-hole trephination with saline irrigation.

Results

The overall post-operative recurrence rate was 19.1% (n=29) in this study. The majority of recurrence showed in Group B. Twenty-eight patients (24.6%) of Group B had recurrence and only 1 patient (2.6%) of Group A showed recurrence. The recurrence rate was significantly higher in Group B compared with Group A (p=0.003). Another affecting factor for the recurrence was the amount of postoperative pneumocephalus (p=0.02). No catastrophic complications were found in postoperative course.

Conclusion

Although there was no difference of clinical outcome in both groups, the recurrence rate was higher in saline irrigation group compared with no irrigation group. We suggest that saline irrigation procedure be reserved only for selected cases in CSDH burr-hole surgery.

Chronic subdural haematoma: modern management and emerging therapies

Chronic subdural haematoma (CSDH) is one of the most common neurological disorders, and is especially prevalent among elderly individuals. Surgical evacuation is the mainstay of management for symptomatic patients or haematomas exerting significant mass effect. Although burr hole craniostomy is the most widely practised technique worldwide, approximately 10-20% of surgically treated patients experience postoperative recurrence necessitating reoperation. Given the increasing incidence of CSDH in a growing elderly population, a need exists for refined techniques that combine a minimally invasive approach with clinical efficacy and cost-effectiveness. In addition, nonsurgical treatment modalities, such as steroids, are attracting considerable interest, as they have the potential to reduce postoperative recurrence or even replace the need for surgery in selected patients. This Review provides an overview of the contemporary management of CSDH and presents considerations regarding future approaches that could further optimize patient care and outcomes.

Chronic subdural hematoma: a systematic review and meta-analysis of surgical procedures

Object

In this paper the authors systematically evaluate the results of different surgical procedures for chronic subdural hematoma (CSDH).

Methods

The MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and other databases were scrutinized according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) statement, after which only randomized controlled trials (RCTs) and quasi-RCTs were included. At least 2 different neurosurgical procedures in the management of chronic subdural hematoma (CSDH) had to be evaluated. Included studies were assessed for the risk of bias. Recurrence rates, complications, and outcome including mortality were taken as outcome measures. Statistical heterogeneity in each meta-analysis was assessed using the T2 (tau-squared), I2, and chi-square tests. The DerSimonian-Laird method was used to calculate the summary estimates using the fixed-effect model in meta-analysis.

Results

Of the 297 studies identified, 19 RCTs were included. Of them, 7 studies evaluated the use of postoperative drainage, of which the meta-analysis showed a pooled OR of 0.36 (95% CI 0.21–0.60; p < 0.001) in favor of drainage. Four studies compared twist drill and bur hole procedures. No significant differences between the 2 methods were present, but heterogeneity was considered to be significant. Three studies directly compared the use of irrigation before drainage. A fixed-effects meta-analysis showed a pooled OR of 0.49 (95% CI 0.21–1.14; p = 0.10) in favor of irrigation. Two studies evaluated postoperative posture. The available data did not reveal a significant advantage in favor of the postoperative supine posture. Regarding positioning of the catheter used for drainage, it was shown that a frontal catheter led to a better outcome. One study compared duration of drainage, showing that 48 hours of drainage was as effective as 96 hours of drainage.

Conclusions

Postoperative drainage has the advantage of reducing recurrence without increasing complications. The use of a bur hole or twist drill does not seem to make any significant difference in recurrence rates or other outcome measures. It seems that irrigation may lead to a better outcome. These results may lead to more standardized procedures.