Stroke (Apoplexy): Surgical Therapy

The acute stroke patient is taken to the nearest stroke unit and treated rapidly with an infusion of the drug alteplase (rt-PA) if indicated. As a rule, lysis (drug therapy used to dissolve blood clots) should be combined with mechanical thrombectomy (removal of an embolus or thrombus with a balloon catheter). It is decided on a case-by-case basis whether thrombectomy is an option. If necessary, the patient is transported to another hospital by ambulance. This is referred to as a “drip-and-ship” or “bridging concept”: First, the patient is taken to a stroke unit, where lysis therapy begins (“drip”). If mechanical thrombectomy is an option, the patient is transported by ambulance to a hospital where thrombectomy is possible (“ship”). The importance of the time window in acute ischemic insult is described by the phrase “time is brain“, i.e. a fast reopening of the vessels is crucial for the prognosis! In this regard, important process criteria should be systematically recorded and adhered to:

  • Time between arrival at the hospital and lysis therapy <60 min.
  • Time between arrival at the clinic and groin puncture < 90 min
  • Time from groin puncture to thrombectomy < 30 min
  • Reperfusion rate (restoration of blood flow (perfusion) in previously occluded vessel) after thrombectomy with TICI (thrombolysis in cerebral infarction) 2b/3 > 75%.

Guideline recommendations:

  • “Mechanical thrombectomy (removal of a clot from a blood vessel) is recommended for the treatment of acute stroke patients with clinically relevant neurologic deficit and large arterial vessel occlusion in the anterior circulation up to 6 hours (time of groin puncture) after symptom onset. In the absence of contraindications, patients should also be treated systemically with rtPA in the 4.5-hour time window (new recommendation).This recommendation is confirmed by a US meta-analysis and others.
  • Mechanical thrombectomy may still be effective later than 6 hours after symptom onset in selected patients. Advanced imaging parameters (eg, mismatch imaging, collateral imaging) should be used to identify patients with high-risk tissue (new recommendation).
  • Mechanical thrombectomy should not delay the initiation of intravenous thrombolysis (dissolution of a thrombus (“blood plug”) using drugs), and intravenous thrombolysis should not delay mechanical thrombectomy; in particular, it is not recommended to wait for a possible rtPA effect before thrombectomy (new recommendation).
  • Potential thrombectomy candidates should receive noninvasive vascular diagnostics (CTA, MRA) without delay to rapidly establish the indication (new recommendation).
  • Mechanical thrombectomy should be performed as soon as possible after the indication is established; the time between arrival at the hospital and groin puncture (door-to-groin time) should be no more than 90 minutes, and the time between groin puncture and thrombectomy initiation should be no more than 30 minutes (new recommendation).
  • Mechanical thrombectomy should achieve reperfusion TICI 2b/3, and a rate of at least 75% TICI 2b/3 should be required for the total number of patients (new recommendation).
  • When acute proximal intracranial vessel occlusion is diagnosed in a hospital without the possibility of mechanical thrombectomy, a “bridging concept” should be used. After initiation of intravenous thrombolysis with rtPA, transfer to a center with endovascular therapy options should occur immediately (modified recommendation). Supplementary imaging after clinical deterioration or prolonged transfers is at the discretion of the neuroradiologist (new recommendation).
  • Stent retrievers should be used for mechanical thrombectomy (new recommendation). Other thrombectomy systems may be used at the discretion of the neuroradiologist if rapid, complete, and safe recanalization of the vessel can be achieved (new recommendation).
  • When intravenous thrombolysis is contraindicated, mechanical thrombectomy is recommended as first-line therapy in patients with occlusion of a proximal basilar cerebral artery (new recommendation).
  • Patients with acute basilar artery occlusion should be treated with mechanical thrombectomy, and if there are no contraindications, together with intravenous thrombolysis (modified recommendation).
  • A clear upper limit of the time window cannot be given; it is probably longer than for occlusions of the anterior circulation. Alternatively, inclusion in randomized trials is possible. Note: The American Heart Association promptly updated its stroke care recommendations in January 2018 after the results of the 2 thrombectomy trials (DAWN trial and DEFUSE-3 trial) became known. Thrombectomy is now recommended in the 6-16 hour window after symptom onset.
  • The choice of sedation depends on the individual situation; regardless of the method chosen, every effort should be made to avoid time delays in thrombectomy (new recommendation).
  • Patients with radiological signs of major infarction (eg, ASPECTS <5) should not be excluded in principle from mechanical thrombectomy if there are other reasons for performing it (such as evidence of additional still-relevant salvageable brain tissue on perfusion imaging) (new recommendation).
  • Advanced age alone is not a reason to forgo mechanical thrombectomy (new recommendation).
  • Mechanical thrombectomy is a complicated interventional procedure reserved for centers with appropriate experience. It should be performed only by interventionalists trained in it (eg, DGNR certification module E) (new recommendation).
  • Centers performing thrombectomy should prospectively record performance figures (e.g., door-to-imaging time, door-to-groin time, recanalization rate, etc.) for quality assurance (new recommendation).

Operative measures after apoplexy

  • In patients who experience apoplexy while on NOAK therapy, endovascular thrombectomy should be used preferentially if indicated and possible.Appropriate for patients with causative occlusion of the anterior cerebral artery, vertebral artery, basilar artery, or posterior cerebral artery.
  • Endovascular therapy is useful only in cases of marked penumbra. To enlarge the penumbra (Latin : penumbra; in cerebral infarction, penumbra is the area immediately adjacent to the central necrosis zone and still containing viable cells): Selection of appropriate patients can be determined by perfusion and diffusion imaging. The infarct core containing irreversibly damaged tissue can be approximately visualized by diffusion-weighted MRI (DWI). The inferiorly perfused areas affected by ischemia are indicated by perfusion-weighted MRI (PWI). The size of the penumbra is described by the difference (mismatch) of PWI and DWI (= salvageable tissue). If the difference is very large, there is a good prognosis, i.e., there is still a chance to avoid major damage.
    • The MR CLEAN trial demonstrated that by means of standard drug thrombolytic therapy (alteplase) in combination with thrombectomy, a better clinical course (10% absolute reduction in the collective with a poor course) occurs than with standard therapy alone. Retrospective data from the MR CLEAN trial show that apoplexy patients who underwent thrombectomy without anesthesia had better clinical outcomes than those treated under general anesthesia.
    • In a study of patients who had a thrombus in the anterior segment of the great cerebral arteries that could be treated within 8 hours of symptom onset, stent-retriever thrombectomy reduced the severity of disability after stroke and increased the rate of functional independence.
    • Elderly patients also benefit from this treatment method. CONCLUSION: Time to treatment is more important than age!In a 2013 update to their guideline, the American Heart Association (AHA) and the American Stroke Association (ASA) recommend mechanical thrombectomy in patients with ischemic stroke with proximal M1 or internal carotid artery occlusions, if such therapy is feasible within six hours of symptom onset.
    • A multicenter study demonstrated that patients benefited from thrombectomy up to 24 hours after the onset of an ischemic insult if there was a marked penumbra around the infarct core. Significantly more achieved recanalization at 24 hours, 77 versus 39%, and infarct volume no longer increased; thus, nearly half of patients were functionally independent at three months.CONCLUSION: Physicians should base their treatment decisions more on the “tissue window” rather than a time window.

    Possible complications after mechanical thrombectomy (mTE): see below.

  • Thrombectomy (removal of a thrombus (blood clot)): Aspiration thrombectomy (removal of a thrombus by suction (aspiration)) versus stent retrieval (randomized trial of 380 patients):
    • By aspiration thrombectomy, the cerebral vessel was slightly more likely to be cleared, but the difference from stent retriever was not significant
    • NIHS score at 24 hours and in functional outcome at three months did not show statistically robust differences
  • Intra-arterial therapy (catheterization to occlusion and release of a thrombolytic agent, mechanical thrombectomy, or both) within 6 hours of the onset of acute ischemic stroke symptoms resulted in patients treated in this manner being less likely to require external assistance with activities of daily living at 3 months compared with conventional therapy (thrombolysis with alteplase).
  • Thrombectomy alone versus i.v. lysis plus thrombectomy:
    • Mortality (death rate) was significantly lower (25%) than with thrombectomy alone (36%); differences disappeared when differences in collaterals and degree of reperfusion were accounted for
    • Good functional outcome (mRS score of ≤ 2 points) was achieved at 3 months by 34% with thrombectomy alone and 40% with combination therapy; the difference was not statistically significant

    Limitation: retrospective data; large controlled trials are needed.

  • The More Severe the Apoplexy, the More Promising Thrombectomy: Thrombectomy should be rated as the first-line procedure in patients with severe and moderate strokes: As a result, thrombectomy was superior to lysis treatment in randomized trials (p<0.001 for lower disability score; p=0.033 for mortality/stroke rate).
  • Cerebral mass hemorrhages must be stopped surgically in some cases. This often involves closing aneurysms (dilations of the vessel wall) with a clip. Increased intracranial pressure may also require surgery, for example, to implant a drainage system.
  • In severe media infarction, a relieving craniotomy (opening of the bony skull and dilatation of the dura mater/outermost meninges) may be performed to relieve pressure, if necessary, to lower the life-threatening pressure inside the skull. The multicenter DESTINY II study shows that this procedure reduces the lethality (mortality) of patients over 60 years of age from 73 to 33 percent.

CONCLUSION: Additional mechanical thrombectomy is superior to i.v. lysis alone for occlusions of large cerebrovascular arteries. Notice:

  • Systemic blood pressure drops must be avoided while vascular occlusion is present to maintain an existing collateral supply.
  • Hypertensive episodes should be avoided after vascular reopening, as they may lead to hemorrhage.

Possible complications after mechanical thrombectomy (mTE):

  • Vasospasm (spasmodic constriction of a blood vessel; 20-25%); are not clinically significant and rarely require specific treatment
  • Emboli (5-9%)
  • Symptomatic bleeding (2-6%); are not more common than after drug therapy (up to 8%).
  • Vascular injury (1-5%)
  • Circumscribed subarachnoid contrast enhancement or hemorrhage occurs in up to 24% of all cases; these are usually benign (benign)

Further notes

  • Intracranial stents significantly increase the risk of recurrent apoplexy and premature death.

Preventive surgical measures

  • For prophylaxis, that is, to prevent stroke, stenosis (narrowing) of the carotid artery (A. carotis) can be treated surgically by a procedure called carotid endarterectomy (CEA). In the process, arteriosclerotic plaques are removed.

Condition after apoplexy in persistent foramen ovale (PFO)

The foramen ovale cordis (Latin : “oval hole in the heart“) is an opening in the atrial septum (thin wall located between the right and left atria) that allows blood to pass from the right (pulmonary circulation) to the left (systemic circulation) in the fetal (prenatal) circulation. The foramen ovale, together with the ductus arteriosus botalli (vascular connection between the aorta and the truncus pulmonalis), allows bypass of the pulmonary circulation. The foramen ovale usually closes postnatally in the first days or weeks of life. If closure does not occur, it is called a persistent foramen ovale (PFO). Approximately 25% of all people have a PFO. Guidelines usually recommend acetylsalicylic acid (ASA) for secondary prevention for PFO patients. Alternatively, the placement of an occluder system inserted by catheter to close an open foramen (called an “umbrella”) is discussed. Studies on this have not yet been convincing:

  • In the PC study, PFO closure by catheter intervention with umbrella was not superior to drug therapy with antiplatelet agents (antiplatelets) or anticoagulants. The collective consisted of 414 patients younger than 60 years with PFO after cryptogenic ischemic stroke, TIA, or peripheral embolism.
  • The RESPECT trial enrolled 980 patients younger than 60 years, all with cryptogenic stroke and PFO. Half received drug prophylaxis (75% received antiplatelet agents, 25% anticoagulants), and the remainder received PFO closure. Primary endpoint was apoplexy recurrence (new stroke). This occurred in 16 patients on drug therapy, but only in nine with PFO closure. Four of the patients in the group with PFO occlusion did not receive the umbrella at all. When the treated group was considered (as-treated analysis), the difference of 16 versus five strokes was statistically significant despite the small number of events.
  • Three meta-analyses (REDUCE, CLOSE, RESPECT extended follow-up) suggest that closure of a patent foramen ovale in “cryptogenic” stroke should be reconsidered because this method can reduce the risk of ischemic stroke recurrence by about 60% compared with drug prophylaxis.

Conclusion:

  • Based on current data, percutaneous PFO closure after cryptogenic stroke/TIA is recommended.
  • Interventional therapy is superior to drug treatment alone in patients with PFO and cryptogenic stroke.
  • The current S2e guideline: cryptogenic stroke and patent foramen ovale recommends, “Interventional PFO closure should be performed in patients between 16 and 60 years of age with a cryptogenic ischemic stroke (after neurologic and cardiologic evaluation) and patent foramen ovale with moderate or marked right-to-left shunt.” [Grade of Recommendation A and Level of Evidence I.]

Elective surgery after apoplexy

  • Elective, noncardiac surgery, within 9 months after apoplexy increases the risk of serious cardiovascular events. If the apoplexy occurred more than 9 months ago, the risk is not higher than in the group without apoplexy. Elective surgery is a procedure that is not really urgent (elective surgery), the timing of which can be chosen almost freely.