Needle Parking Interrupted Suturing Technique for Microvascular Anastomosis: A Technical Note

BACKGROUND Interrupted and continuous suturing are 2 common techniques for microvascular anastomosis in cerebrovascular surgery. One of the technical complexities of interrupted suturing includes the risk of losing the needle in between interrupted sutures during knot tying, which may result in unnecessary movements and wasted time. OBJECTIVE To report a new needle parking technique for microvascular anastomosis that addresses a needle control problem during interrupted suturing. METHODS The needle parking technique involves puncturing both vessel walls at the site of the next provisional suture and leaving the needle parked in place while the knots at the first suture are being made. The thread is then cut, the needle is pulled through, and the process is repeated. Illustrative cases in which the needle parking technique was used are presented. We also compared time of anastomosis completion between the conventional interrupted, needle parking interrupted, and continuous suturing techniques during an in vitro study on standardized artificial vessels. RESULTS This technique is being used successfully by the senior author for various cerebrovascular bypass surgeries. The in vitro study demonstrated that the needle parking technique can be significantly faster than the conventional interrupted suturing technique and may be as fast as continuous suturing. CONCLUSION Needle parking technique is a modification of conventional interrupted suturing and solves the problem of losing the needle during knot tying. This technique is simple, prevents unnecessary movements, and may result in a faster anastomosis time.

Intraoperative indocyanine green video angiography (ICG–VA) with FLOW 800 software in complex intracranial aneurysm surgery

Background Indocyanine green video angiography (ICG–VA) is a safe and effective instrument to assess changes in cerebral blood flow during cerebrovascular surgery. After ICG-VA, FLOW 800 provides a color-coded map to directly observe the dynamic distribution of blood flow and to calculate semiquantitative blood flow parameters later. The purpose of our study is to assess whether FLOW 800 is useful for surgery of complex intracranial aneurysms and to provide reliable evidence for intraoperative decision-making. Methods We retrospectively reviewed patients with complex aneurysms that underwent microsurgical and intraoperative evaluation of ICG-VA and FLOW 800 color-coded maps from February 2019 to May 2020. FLOW 800 data were correlated with patient characteristics, clinical outcomes, and intraoperative decision-making. Results The study included 32 patients with 42 complex aneurysms. All patients underwent ICG-VA FLOW 800 data provided semiquantitative data regarding localization, flow status in major feeding arteries; color maps confirmed relative adequate flow in parent, branching, and bypass vessels. Conclusions FLOW 800 is a useful supplement to ICG-VA for intraoperative cerebral blood flow assessment. ICG-VA and FLOW 800 can help to determine the blood flow status of the parent artery after aneurysm clipping and the bypass vessels after aneurysm bypass surgery.

Intraoperative Transradial Angiogram

Intraoperative angiogram (IOA) is a valuable tool for cerebrovascular surgery. It confirms surgical outcomes for a variety of pathologies. It allows early identification of any residue or compromise of a parent vessel. This chapter will delve into the advantages, limitations, and technical nuances of IOA via a radial approach. IOA is a valuable tool for cerebrovascular surgery. IOA allows early diagnosis and identification of any residue and obviates the need for postoperative diagnostic angiogram. It confirms surgical outcomes for a variety of pathologies such as aneurysm occlusion and parent vessel patency, arteriovenous malformation resection, dural fistula ligation, bypass patency, and adequate carotid revascularization after endarterectomy. Though there are alternatives, such as indocyanine green fluorescence (ICGA) angiography, formal angiography remains the gold standard as it overcomes the limitations of ICGA. Femoral access has been the main approach for IOA with an excellent safety profile. Recently the radial approach has been gaining wide interest among neurointerventionalists, and there are several advantages for the radial approach over the femoral approach in IOA.

Adenosine-induced transient circulatory arrest in transvenous embolization of cerebral arteriovenous malformations

Due to advances in interventional techniques, the transvenous approach may present an effective treatment option for embolization of brain arteriovenous malformations (AVMs). Contrary to the transarterial method, the transvenous approach can only be utilized in a specific subset of patients and is not suitable as a standard procedure for all AVM lesions. While this technique can be helpful in certain patients, careful patient selection to ensure patient safety and favorable clinical outcomes is important. However, especially in high-flow AVMs, targeted deposition of embolic materials through a transvenous access can be challenging. Therefore, a temporary flow arrest may prove helpful. Transient cardiac arrest by use of adenosine has been applied in cerebrovascular surgery but is not common for endovascular embolization. Adenosine-induced arrest and systemic hypotension may be a feasible, safe method to reduce flow and help endovascular transvenous embolization of certain AVMs. Our study evaluated the efficiency and safety of adenosine-induced circulatory arrest for transvenous embolization of cerebral AVMs.

Impact of acetylsalicylic acid in patients undergoing cerebral aneurysm surgery – should the neurosurgeon really worry about it?

There has been an increase in the use of acetylsalicylic acid (ASA, Aspirin®) among patients with stroke and heart disease as well as in aging populations as a means of primary prevention. The potentially life-threatening consequences of a postoperative hemorrhagic complication after neurosurgical operative procedures are well known. In the present study, we evaluate the risk of continued ASA use as it relates to postoperative hemorrhage and cardiopulmonary complications in patients undergoing cerebral aneurysm surgery. We retrospectively analyzed 200 consecutive clipping procedures performed between 2008 and 2018. Two different statistical models were applied. The first model consisted of two groups: (1) group with No ASA impact - patients who either did not use ASA at all as well as those who had stopped their use of the ASA medication in time (> = 7 days prior to operation); (2) group with ASA impact - all patients whose ASA use was not stopped in time. The second model consisted of three groups: (1) No ASA use; (2) Stopped ASA use (> = 7 days prior to operation); (3) Continued ASA use (did not stop or did not stop in time, <7 days prior to operation). Data collection included demographic information, surgical parameters, aneurysm characteristics, and all hemorrhagic/thromboembolic complications. A postoperative hemorrhage was defined as relevant if a consecutive operation for hematoma removal was necessary. An ASA effect has been assumed in 32 out of 200 performed operations. A postoperative hemorrhage occurred in one out these 32 patients (3.1%). A postoperative hemorrhage in patients without ASA impact was detected and treated in 5 out of 168 patients (3.0%). The difference was statistically not significant in either model (ASA impact group vs. No ASA impact group: OR = 1.0516 [0.1187; 9.3132], p = 1.000; RR = 1.0015 [0.9360; 1.0716]). Cardiopulmonary complications were significantly more frequent in the group with ASA impact than in the group without ASA impact (p = 0.030). In this study continued ASA use was not associated with an increased risk of a postoperative hemorrhage. However, cardiopulmonary complications were significantly more frequent in the ASA impact group than in the No ASA impact group. Thus, ASA might relatively safely be continued in patients with increased cardiovascular risk and cases of emergency cerebrovascular surgery.