Vrednost saturacije s kisikom v možganih med karotidno endarteriektomijo za napoved možganske okvare

Makovec, Matej (author), Klokočovnik, Tomislav (mentor), Skitek, Milan (comentor)

Izhodišče: Karotidna endarteriektomija (KE) je operativni poseg, za katerega je bilo ugotovljeno, da pri povečani stopnji zožitve karotidne arterije zmanjša verjetnost možganske kapi (MK). Možen zaplet operacije pa je lahko MK. Glavni vzrok možgansko-žilnega dogodka je manjši pretok krvi skozi možgane med pretisnjenjem vratne arterije. Takojšnja in pravilna prepoznava nezadostnega kolateralnega pretoka je ključna za dober izhod operativnega posega. Splošna uporaba začasnega žilnega obvoda (šanta) med operativnim posegom poveča zahtevnost operacije, lahko poškoduje žilno steno, kar vodi v tromboembolizem. Iz tega izhaja, da potrebujemo nevromonitoring, ki bi selekcioniral bolnike, ki bodo imeli od vstavitve šanta korist. Bolniki, pri katerih je KE opravljena v lokalni anesteziji (LA), so klinično nadzorovani. Nevrološki nadzor je videti najboljši način spremljanja, nevromonitoringa, bolnika med KE. Nevrološki nadzor ni možen pri bolnikih operiranih v splošni anesteziji, zaradi česar se išče dober nevrološki nadzor za operirance v splošni anesteziji. Objektivno vrednost metod spremljanja bolnikov med KE smo vrednotili s proučevanjem serumske koncentracije biokemičnih označevalcev možganske poškodbe, proteina S100B in NSE (nevronske specifične enolaze). Nevromonitoring je možno izvajati tudi z meritvami oksigenacije v možganih (rSO2) pri budnem in operirancu v splošni anesteziji (NIRS). Zanimala nas je učinkovitost nevromonitoringa S100B, NSE in rSO2 med KE. Postavili smo hipotezo, da povišane serumske koncentracije S100B in NSE ter NIRS med KE lahko korelirajo s pojavom nevrološke simptomatike med posegom. Bolniki in metode: V študijo je bilo vključenih 60 operirancev, pri katerih smo v obdobju 12 mesecev opravili 64 KE v LA. Spremljali smo NIRS, S100B in NSE pred pretisnjenjem karotidne arterije in po njem. Za vstavitev šanta smo se odločili glede na nevrološko simptomatiko med KE, ne glede na NIRS. Nevrološka simptomatika (nevrološko simptomatska skupina) se je pojavila pri 7 (10,9 %) operirancih. Pri 57 (89,1 %) operirancih med posegom ni bilo pojava nevrološke simptomatike (nevrološko asimptomatska skupina). Rezultati: Nevrološka simptomatika, ki se je pojavila po pretisnjenju karotidne arterije, je korelirala s povišano serumsko koncentracijo S100B (P = 0,040). Optimalno povišanje serumske koncentracije proteina S100B, ki napoveduje pojav nevrološke simptomatike, je 22,5 %. Nismo našli korelacije med padcem NIRS in pojavom nevrološke simptomatike (P = 0,675). Padec NIRS za 13 % se je pokazal kot najoptimalnejša vrednost za napoved pojava nevrološke simptomatike med posegom. Med operacijo ni prišlo do povišanja serumske koncentracije NSE glede na izhodiščne vrednosti. Dva operiranca (3,1 %) sta utrpela perioperativno MK. Zaključek: Nevrološki nadzor operirancev med KE je možen pri posegih v LA. Izkazalo se je, da je dober pokazatelj prekrvitev možganov med posegom. Patološke vrednosti nevrološkega nadzora so korelirale z objektivnim pokazateljem poškodbe možganov, nivojem S100B. Čeprav smo med KE ugotovili povezavo med pojavom nevrološke simptomatike in porastom serumske koncentracije S100B, spremljanje S100B z namenom nevromonitoringa med KE ni možno zaradi dolgega časa analize vrednosti S100B v serumu. Statistično značilne korelacije med pojavom nevrološke simptomatike med KE in padcem NIRS nismo ugotovili. Do povišanja NSE med posegom ni prišlo. Spremljanje proteina S100 se je izkazalo kot boljši nevromonitoring od NIRS. Trdni zaključki naše študije niso možni zaradi majhnega števila operirancev, ki so bili vključeni v študijo, posebej v nevrološko simptomatski skupini. Za potrditev ali izključitev naših predpostavk so potrebne dodatne študije.

• Language: Slovenian
• Keywords: preprečevanje perioperativne možganske kapi, nevromonitoring, zožitev karotidne arterije, selektivna vstavitev šanta
• Work type: Doctoral dissertation
• Organization: MF - Faculty of Medicine
• Year: 2021
• PID: 20.500.12556/RUL-125126
• COBISS.SI-ID: 61110275
• Publication date in RUL: 05.03.2021

Secondary language

• Language: English
• Title: The predicitive value of the oxygen saturation of brain during the carotid endarterectomy for the brain injury

Abstract

Background: Carotid endarterectomy (CEA) is a surgical procedure that has been found to reduce the risk of stroke (ischaemic cerebral infarction) in patients with severe carotid artery stenosis. However, its inherent risk is perioperative stroke. Cerebrovascular accidents frequently result from hypoperfusion during cross-clamping of the internal carotid artery (ICA). Prompt and reliable recognition of insufficient collateralisation is thus crucial for a good neurological outcome in patients. Widespread use of a temporary indwelling shunt adds to the complexity of endarterectomy, and may result in injury to the arterial wall, leading to thrombembolism. Proper neuromonitoring is therefore needed to identify patients who would benefit from shunt placement. Patients undergoing CEA under local anaesthesia (LA) are monitored clinically, which arguably results in a more appropriate shunt insertion method than other, less sensitive neuromonitoring methods. Neuromonitoring is not possible in patients operated on under general anaesthesia, which is why a good alternative monitoring method is sought for them. The objective value of monitoring methods for patients during CEA was evaluated by studying the serum levels of the S100B and NSE (neuron-specific enolase) proteins, the biochemical markers of brain injury. Neuromonitoring can also be performed by measuring brain oxygenation (rSO2) in the treated patient when awake and when undergoing general anaesthesia (rSO2). The study investigated the effectiveness of measuring the serum levels of S100B, NSE, and rSO2 for the purposes of neuromonitoring. We hypothesised that increased serum S100B and NSE levels and rSO2 during CEA would correlate with neurological symptoms during the surgical procedure. Patients and methods: A total of 64 consecutive CEAs in 60 patients operated on under LA during a 12-month period were prospectively evaluated. A cerebral oximeter was used to measure rSO2 before and after cross-clamping along with serum concentration of the S100B and NSE proteins. Selective shunting was performed when neurological changes occurred, regardless of rSO2. Neurological deterioration occurred in seven (10.9%) operations (neurological symptoms group). In 57 (89.1%) operations, the patient was neurologically stable (no neurological symptoms group). Results: Neurological symptoms that occurred after carotid artery cross-clamping correlated with an increased S100B serum level (p = .040). The S100B protein serum level increase rate optimally forecasted the development of neurological symptoms at 22.5%. A correlation of rSO2 decline and the occurrence of neurological symptoms (p = .675) or increased serum NSE levels was not found regardless of the baseline levels. A drop of NIRS by 13% emerged to be the most optimal value to predict neurological symptoms in the procedure. Two (3.1%) perioperative strokes were recorded. Conclusion: Awake neuromonitoring is inherently specific for CEA under LA and has been shown to be a sensitive direct measure of intraoperative cerebral tissue perfusion. Pathological neuromonitoring levels correlated with serum S100B levels, which are an objective indicator of brain injury. Although a positive association was identified between neurological symptoms during CEA and increased serum S100B levels, S100B monitoring is not feasible during CEA due to a long evaluation time (laboratory analysis usually takes >3 h). There was no statistically significant correlation between rSO2 decline during CEA and neurological symptoms. NSE did not increase during the procedure. S100 monitoring was found to be a better method of neuromonitoring than NIRS. Firm conclusions cannot be drawn due to the small number of patients involved in the study, particularly in the neurological symptoms group. Further studies will be required to confirm or refute our hypotheses.

• Keywords: perioperative stroke prevention, neuromonitoring, carotid stenosis, selective shunting