INTRODUCTION : Surgical treatment strategies, and decisionson how and when to perform an operation, have historically largely been basedon traditions and the surgeon's own personal experience and preference. Havingreached low mortality rates in neurosurgery, focus has discretely shiftedtowards patient-reported outcomes, such as functional scores and health relatedquality of life . Surgical patriarchs are being challenged by patientinvolvement, i.e. shared decision-making, which relies highly on correctpreoperative risk benet assessments. The need for clinicians to keep updated -critically evaluating and embracing quality research, continuously askingquestions about own practice, is essential. In 2018 “the human factor” insurgery and patient treatment is still as crucial as in Cushing's time, and theneed for quality assessment of clinical practice sustains. Safe surgeryprocedures and increased focus on patient safety has become a natural part ofour everyday surgical work, and routines for aberrations and constantimprovement in patient care is more streamlined than only a decade ago. In thisstudy the perioperative time period is denied as the 24 hours before surgeryand the rest 30 days postoperatively. A decision to perform or undergo brainsurgery is different than many other types of surgical decisions, simplybecause this organ can be non-forgiving if even the smallest mistake is made.As neurosurgeons, we are regularly confronted with complications, andconstantly reminded to stay alert throughout working hours both in theoperation theater and in outpatient clinics where crucial decisions are made.Considering the high demands of treatment quality, evidence-based guidelinesfor neurosurgical treatment and perioperative quality handling are stillsurprisingly scarce
Chronic SDH : Evacuation of chronic subdural hematoma is oneof the most common neurosurgical procedures. It is most often encountered inthe elderly . The number of CSDH patients is expected to increase as the oldestsegment of the population continues to grow. According to the prognosis for2030, CSDH is expected to be the most common intracranial neurosurgicalcondition in India. Incident rates for surgical intervention is reported 10-20/100.000 per year in different materials.
Pathophysiology : The pathophysiology is still debated andnot fully understood . What we do know, is that rupture of bridging veinsrunning from the cortical surface into the dura and greater venous intracranialsinuses leads to accumulation of blood in the subdural space. Cerebral atrophy,which comes naturally with age, contributes to “stretching” of the veins -making them prone to rupture with only minor trauma. One supplemental theory isthat hyperangiogenesis and micro bleedings in the so-called neomembrane mightplay a role in the development of, and especially in the recurrence of, CSDH.Arbitrarily divided into 3 stages. i.e. Acute SDH-1 to 3 days from injury; Subacute SDH- 4 to 21 days of injury; Chronic SDH -after 3 weeks of injury.Treatment is technically not very demanding. However, the patients are oftenold and carry comorbidity. There is practically no upper age limit for goingthrough surgery for CSDH - left untreated the hematoma often cause severeneurological damage and death. The surgery is mini-invasive, mostly done underlocal anesthesia in combination with sedation. After a 3-4 cm skin incision, asmall burr hole in the skull is made. The surgeon then enters the subduralspace which is easily reached through the dura mater, and the blood is washedout. The procedure typically takes 20-30 minutes, and the overall outcome isgenerally good, and the morbidity and mortality rates related to the surgicalprocedure is low. The use of postoperative drainage systems for the restpostoperative hours is common.
Aim and Objective : Retrospective study done from August2016 to January 2019 (30 months) To compare recurrences after chronic subduralhematoma burrhole surgery using three different postoperative drainagetechniques. To establish the risk of recurrence in patients with chronicsubdural hematoma on antithrombotic treatment, and explore if timing ofresumption of antithrombotic treatment inuence the occurrence ofthromboembolism and hematoma recurrence
Materials and methods : This retrospective study is based onthe collected experience of 270 patients who were managed for chronic subduralhematoma with Burr hole evacuation at Thanjavur Medical college Hospital, whichcaters neurotrauma care for nearly six districts in its vincity. Data collectedfrom our neurotrauma registry (August 2016 – January 2019) has been used forthe analysis. A total of 270 patients were included in the study. Patients whodied post operatively due to systemic complications were excluded from thestudy. All patients included in the study were adults (age 27 years or older)To ensure high-quality data for primary endpoints which now focused onantithrombotic therapy and the timing of resumption of AT medication as potentialfactors inuencing recurrence rate and complications. 177 patients wereincluded. Once patients presenting to our emergency department or referred fromother supporting departments, we have had their cardiopulmonary statusassessed, they have a rapid and directed neurologic examination and appropriateimaging. In our facility, patients with chronic subdural hematoma with morethan 5 mm of shift proceed to the operating room, irrespective of the GCS,unless brain-dead. Trauma registry data are prospectively recorded by thetreating doctors during routine clinical care. Trained clinical dataspecialists abstract additional data from the medical record for review andreporting purposes treatment Data collected include the age of the patient, historyof injury/ trivial trauma in the past, interval between the time of trauma andtime of admission to the hospital, neurological and hemodynamic status at thetime of admission, co-morbidities Anti-thrombotic therapy (type and duration) Anti-epileptic(type and duration) other associated injuries, respiratory efforts, imagingresults, Necessity for post-operative ventilator support and post-op care.
Recurrence of chronic subdural hematoma : We denied theindex operation as the rest surgical procedure on the affected side. Bilateralhematomas were registered as one index operation is both sides were treated aspart of the same procedure. A recurrent CSDH was denied as same-sided CSDHrecurrence treated with surgery within 6 months of the index operation. In thecases in which a one-sided index operation was followed by a bilateralrecurrent procedure (i.e., one recurrent side and one untreated side), thepatient was still registered as having only one index operation and onereoperation.
Clinically relevant postoperative hematoma : A clinicallyrelevant postoperative hematoma was denied as radiologically detected hematomahaving any possible association with postoperative course/events, includingprolonged observation in intensive care unit, delayed mobilization, possiblyrelated neurological deceits including transient deceits, or more severerelated events like impaired consciousness or death. All reoperations forpostoperative hematomas were obviously registered as such, being one of the secondaryend points.
Venous thromboembolic events : The rest-line diagnosis of DVT and PE is lower extremityultrasonography and contrast-enhanced chest computed tomography, respectively.We did not performed VTE screening in asymptomatic patients.
Observations Summary of Results : Assessment of drainagetechniques for evacuation of chronic subdural hematoma Recurrence in need ofsurgery was observed in 10.8% in the continuous irrigation and drainage cohort(CID), in 20.0% in the passive drainage cohort (PD), and in 11.1% in the activedrainage cohort (AD).
Role of antithrombotic therapy in the risk of hematomarecurrence and thromboembolism after chronic subdural hematoma evacuation Therewas no difference in CSDH recurrence within 3 months (11.0% vs. 12.0%, p=0.69),nor was there any difference in perioperative mortality (4.0 % vs. 2.0%,p=0.16) between those using antithrombotic therapy (AT) compared to those whowere not. Perioperative morbidity was more common in the AT group compared tono-AT group (10.7% vs. 5.1%, p30 days) AT resumption, there was no differencewith respect to recurrence (7.0% vs. 13.9%, p=0.08), but more thromboembolism inthe late AT resumption group.
Strengths and limitations : The chronic subdural hematomastudies, we found that AD and CID were associated with a lower chance ofreoperation due to CSDH recurrence compared with only PD postoperatively. Morecomplications were observed in patients treated with CID. The differences inoutcomes across cohorts remained following adjustments for baselinecharacteristics. The major strength of this study is a very high compliancewith treatment strategy in combination with the population-based approach. Thestudy included large number of patients with low rates of missing data. Comparativeeffectiveness research is prone to confounding factors. To minimize the risk ofconfounding, registration of data included variables known to potentiallyinuence primary endpoint, such as the indication for repeat surgery. However,we did not use propensity score matching or other advanced statistical methodsin further attempts to control confounding. Limitations inherent toretrospective assessment are present in this study. The difference in outcomesmay be at least in part due to the fact that each type of procedure wasperformed at different hospitals and by different surgical teams. Differencesin general postoperative management is a concern, and the way it couldcontribute to differences between groups. These differences are difcult to control,especially in retrospect, and are complex and dependent on othernon-controllable factors like available hospital beds and the constant need forpatient turn-over in highly specialized regional centers. We cannot exclude thepossibility that observer/consultant differences in treatment indications,follow-up routine, or indications for reoperations may have affected ourndings. In the PD cohort, patients were routinely screened 4 weekspostoperatively with a visit in the outpatient clinic and a CT scan, whileradiology controls were performed based on clinical symptoms in the CID and ADcohort. The risk of detection bias is present, but the indications forreoperations showed not to be different between cohorts based on ourretrospective review, as patients had to present with relevant clinicalsymptoms in addition to radiological ndings. The difference in recurrencesbetween cohorts was large, and although the above mentioned may have inuencedour results, given the magnitude of recurrence rate, bias alone is unlikely tofully explain the observed difference. Safety around continuous inow-and outowirrigation has always been a concern. We did nd increased morbidity in the CIDcohort. However, in this cohort a higher percentage of the patients had generalanesthesia, and in some cases, there was also delayed mobilization. Two recentstudies reported that general anesthesia was associated with higher morbidityand longer hospital stays that sedation combined with local anesthesia. ThisCID cohort was also more frequent users of antithrombotic treatment, whichtheoretically could explain the higher morbidity rate as well as the fact thatthe recurrence rate in this time period was surprisingly higher than reportedin the Hennig article in 1999 that 37 described a residual rate of remarkablylow 2,6%. The results from Anthithrombotic therapy group however, dismissesthis theory as perioperative morbidity was the same in both groups and ATtreatment did not affect recurrence rates. We have no good explanation as towhy the current CID cohort performed worse than the earlier series except thedesign of the 1999 study which can be questioned concerning power and setup. 1991technique was introduced only a few years before the publication. If looking atthe IDEAL framework for surgical innovation, early adopters and pioneers tendto be extra enthusiastic of techniques. Patients may therefore be treated inexpert hand with enthusiastic team. However, with dissemination to othercaregivers, external validity increases and results usually drop. In AT group,we found that in clinical practice, CSDH patients on AT therapy at the time ofdiagnosis have similar recurrence rates and mortality compared to those withoutAT therapy, but with higher morbidity. Early resumption was not associated withmore recurrence, but with lower thromboembolic frequency. Early AT resumptionseems favorable. Some of the limitations in this group are similar to previousgroup because of its retrospective assessment. The data on CSDH recurrence andpostoperative thromboembolism frequency after pausing antithrombotic treatmentremain indisputable, but a limitation exists in the lack of long-term followupdata. The validity of the study is limited by the surgeons often subjectivedecision on when to resume AT therapy. Resumption may be confounded byindication since AT may be withheld in presumed high-risk patients for reasonswe cannot control in retrospect despite having comparable baselinecharacteristics. The external validity is limited in the sense that “early”resumption on AT therapy is dened as within 30 days. Even if the median numberof days post surgery in the early group for resumption was 16, one could stilldebate whether this nding could change clinical policy. However, the ndingsjustify an RCT that can push the borders for resuming AT therapy even earlier –as one now knows that there is an increased risk of VTE with late resumption atthe same time there was no increased recurrence rate if early resumed.Practical implications of this study: We have changed drainage technique forevacuating CSDH from continuous irrigation and drainage and from passive subduraldrainage to active subgaleal drainage. There is ongoing quality control.