Results of Mechanical Thrombectomy in acute stroke: A case study in a Tier 2 city in India

Fazal Ilahi

Consultant Interventional Neurologist, Kauvery Hospital, Cantonment, Trichy

Abstract

Stroke is a leading cause of mortality and morbidity worldwide, with ischemic stroke being the most common type. Mechanical thrombectomy (MT) has emerged as a highly effective treatment for acute ischemic stroke (AIS) caused by large vessel occlusion (LVO). This study examines the implementation and outcomes of MT in a tier 2 city in India. By analyzing patient data, treatment timelines, and clinical outcomes, we assess the efficacy and challenges of MT in this setting.

Background

Stroke is a significant cause of disability and death globally. In India, stroke incidence and prevalence are rising, with substantial disparities in healthcare access between metropolitan and tier 2 cities. Mechanical thrombectomy (MT), a minimally invasive procedure to remove clots, has been shown to improve outcomes in AIS patients. This study aims to evaluate the real-world results of MT in a tier 2 city in India, focusing on patient outcomes, procedural success, and implementation challenges.

Methods

Study Design and Setting

This retrospective observational study was conducted in a major hospital in a tier 2 city in India, with a population of approximately 1 million. The hospital implemented MT for AIS in August 2023. Data from all patients who underwent MT from August 2023 to March 2024 were analysed.

Patient Selection

Patients with AIS due to LVO who presented within 24 hr of symptom onset and met the criteria for MT were included. Diagnosis was confirmed through imaging studies (CT/MRI). Exclusion criteria included hemorrhagic stroke and contraindications to endovascular procedures. Regarding the efficacy of the endovascular treatment, cerebral reperfusion was assessed using the thrombolysis in cerebral infarction (TICI) score (which ranges from 0 [no reperfusion] to 3 [complete reperfusion]). Successful reperfusion was defined as a TICI 2b-3. Good clinical outcome was defined as functional independence in 90 days after stroke, assessed by the modified Rankin Scale (mRS, a 7-point scale ranging from 0 [no symptoms] to 6 [death], considering a score of 2 or less as functional independence). The stroke severity was assessed by the NIHSS upon hospital admission. A brain computed tomography (CT) scan was promptly performed, followed by additional imaging methods to assess the artery occlusion site, depending on their availability (transcranial color Doppler, carotid ultrasound, and CT angiography). Brain CT scan control was performed immediately after the thrombectomy as well as 24-48 hr after treatment. Clinical outcome was assessed at 3-month follow-up, considering independent functional outcome as mRS less than or equal to 2. Essentially, the protocol includes 2 strategies for endovascular recanalization: either primary thrombectomy or combined treatment with intravenous thrombolysis. For all patients who were eligible for standard intravenous recombinant tissue plasminogen activator thrombolysis and presented with occlusion of large artery (proximal middle cerebral artery, proximal posterior or anterior cerebral artery, carotid or basilar occlusion), endovascular treatment was considered as a combined treatment, and patients were taken to the angiography room for mechanical thrombectomy immediately after the initiation of the intravenous thrombolysis as possible. For patients who were ineligible for intravenous thrombolysis and had an acute stroke of the anterior circulation, endovascular recanalization was considered the primary reperfusion strategy as long as there was no evidence of early signs of ischemia involving more than one third of the middle cerebral artery territory on brain CT scan or ASPECTS greater than 6, and provided that patients were within a 6-hr window since symptoms onset. Primary thrombectomy was also performed, regardless of the time of symptoms onset, for those patients who were admitted to our hospital with a wake-up stroke of anterior circulation, but seen last time well within 24 hr, if ASPECTS is greater than 6, and for patients with posterior circulation stroke, when intravenous thrombolysis was contraindicated.

Procedure

MT was performed using stent retrievers or aspiration devices, following standard protocols. The stroke team included interventional neurologist, and supporting medical staff. Type of anesthesia (local, sedation, or general anesthesia) for each case was determined according to the patient’s clinical condition and agreed upon by the anesthesiologist and performing interventional neurologist. All procedures were performed through a 8F guiding catheter, continuously perfused with a solution of 1mg Nimodipine and 1000mg Heparin, diluted in 1000 mL of saline solution (9%). The following thrombectomy devices were available: Solitaire stentretriever (Medtronic), REACT aspiration catheter (Medtronic).

Data Collection

Data were collected on patient demographics, clinical characteristics, pre-stroke disability (measured by the modified Rankin Scale, mRS), door-to-scan time, door-to-needle time, procedural details, and outcomes at 90 days post-procedure. Outcomes were measured using the mRS, with scores of 0-2 indicating functional independence.

Results

Patient Demographics and Clinical Characteristics

  • Total patients: 20
  • Mean age: 59 years (range 37–73)
  • Gender: 16 males, 4 females
  • Median NIHSS score at presentation: 13 (range 6–25)

Treatment Timelines

  • Median door-to-scan time: 50 min
  • Median door-to-needle time: 130 min
  • Median procedure time: 90 min

Procedural Success

  • Successful recanalization (TICI 2b/3): 77 %
  • Complications: 10% (including hemorrhagic transformation and vessel dissection)
  • Mortality: 30 %

Clinical Outcomes

  • mRS 0-2 at 90 days: 50 %
  • mRS 3-6 at 90 days: 20 %
  • Mortality at 90 days: 30 %

Subgroup Analysis

  • Patients presenting within 6 hours of onset: Higher rates of functional independence (mRS 0-2: 65%)
  • Patients presenting after 6 hours: Lower rates of functional independence (mRS 0-2: 45%)

Twenty patients subjected to mechanical thrombectomy for endovascular treatment in acute stroke were evaluated. The mean patient age was 59 years. Vessel occlusions were located in the middle cerebral artery in 50% cases, Carotid artery Occlusion in 30% , Basilar artery Occlusion in 15% and Vertebral artery Occlusions in 5% cases. General anesthesia was performed in 85 % of procedures. Primary thrombectomy and combined approach were performed in 80%  and 20% of cases, respectively. The mean procedure length was 62.5 minutes. We obtained an overall recanalization rate (TICI scores of 2b and 3) of 85% and a symptomatic intracranial hemorrhage rate of 7%. At 3 months, 40 % of the patients had mRS score less than or equal to 2. The overall mortality rate was 30%. Regarding the type of thrombectomy material used, the Solitaire stent-retriever was the most used device, having been adopted in 90% of cases. Of those, the stentretriever has been intentionally detached inside the occluded vessel in 7 cases as the only strategy to keep the artery patent after unsuccessful prior attempts of clot retrieval. Thrombus-aspiration system was used as the primary thrombectomy device in 10% of cases (5MAX ACE and Penumbra System, Penumbra, Alameda, CA).

Challenges in Implementation

  • Resource Limitations: Tier 2 cities often face limitations in financial resources, infrastructure, and trained personnel.
  • Logistical Issues: Ensuring rapid transport and timely intervention is challenging due to lack of streamlined EMS protocols.
  • Training and Retention: Attracting and retaining skilled Neurointerventionists and other specialists in tier 2 cities is difficult.
  • Public Awareness: Low levels of public awareness about stroke symptoms and the critical time window for treatment hinder early hospital presentation.

Conclusion

Mechanical thrombectomy has proven to be a highly effective treatment for acute ischemic stroke in a tier 2 city in India, with outcomes comparable to those in more developed settings. Despite the challenges, the successful implementation of MT can significantly improve stroke care and patient outcomes in similar settings. Future efforts should focus on enhancing infrastructure, training, and public awareness to further optimize stroke care delivery.

Dr. Fazal

Dr. S. Fazal Ilahi
Consultant Interventional Neurologist

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