Definitive Clip Research Articles

Clinical Characteristics and Outcome of Patients With Intraoperative Aneurysm Rupture: A Retrospective Cohort Study From Nepal

BACKGROUND AND OBJECTIVES: Intraoperative aneurysm rupture (IAR) is a significant complication during microsurgical clipping of cerebral aneurysms. The timing of rupture during surgery, morphology of the aneurysm, and strategies to mitigate risk are the key factors that influence the outcome. METHODS: Consecutive patients with the diagnosis of ruptured cerebral aneurysms were retrospectively reviewed at a single University Hospital in Kathmandu, Nepal. Variables analyzed included age, sex, presenting symptoms, Hunt and Hess grades, the location of aneurysms, the timing of surgery, and intraoperative rupture status. Outcomes were assessed at 6 months after surgery. RESULTS: A total of 199 patients with 231 ruptured cerebral aneurysms from July 2014 to December 2022 were reviewed. Surgery was performed within 3 days in 60 (30.1%) patients. Twenty aneurysms ruptured intraoperatively in 20 patients (10% per patient and 8.6% per aneurysm). Patients with IAR were significantly younger (mean age 52 years) than those without IAR (mean age 58 years) (P < .001, 95% CI: 3.72-8.28). There was no difference in IAR rate in early vs late surgery. Anterior communicating artery complex aneurysms were noted as the most common. However, posterior inferior cerebellar and posterior cerebral artery aneurysms had the highest IAR rate, albeit with the smallest total number. Rupture during dissection was noted in 10 (50%) and during clipping in 9 (45%) procedures. Strategies for handling IAR included direct definitive clip application in 9, temporary clip-aided permanent clipping in 8, and trapping of the parent vessel in 1 patient. Although postoperative complications were significantly higher in the IAR group (P < .000129), the neurological outcomes using the modified Rankin scale in 6 months were similar (P = .877). CONCLUSION: The demographic and clinical characteristics and rates of IAR in our patient population are similar to those in the contemporary literature. In patients with IAR, the outcome is not worse than those without IAR.

Surgical treatment of previously embolized craniocervical junction dural arteriovenous fistula.

Craniocervical junction dural arteriovenous fistulas (dAVFs) are rare vascular lesions with a potentially dangerous natural history due to the onset of neurological deficit secondary to intracranial hemorrhage or myelopathy due to venous congestion. Despite advances in endovascular techniques, many dAVFs located in this area continue to require surgical treatment as embolization is often not feasible or safe. In this video, the authors illustrate a patient with a symptomatic craniocervical junction dAVF who had undergone attempted Onyx embolization at another institution. Because of persistent filling of the fistula and worsening myelopathy after the previous attempt, the patient was referred to the authors' clinic for definitive surgical treatment. The video illustrates the typical location of the early draining vein in most craniocervical junction dAVFs immediately below the emergence of the vertebral artery from the dura. The patient underwent successful definitive clip ligation of the fistula, which was exposed through a lateral suboccipital craniotomy.The video can be found here: https://youtu.be/Bvg6VKLgwO0.

Suprapraorbital “key-hole” Approach for Surgical Treatment of Middle Cerebral Artery Aneurysms

Objective. To describe details and technical difficulties observed in the use of this access for the treatment of middle cerebral artery aneurysms. Methods. This is a retrospective study including 15 patients with middle cerebral artery aneurysm operated on using this technique (two ruptured aneurysms and 13 incidental aneurysms). We considered age, gender, laterality of the aneurysm, and whether it was ruptured. We evaluated the surgical corridor (surgical field exposure and ease of handling of the surgical instruments), surgery time, complications, functional and cosmetic results. Results. This access provides adequate exposure of the surgical field, but the restricted working angle makes it difficult to dissect the aneurysm and, especially, to place the definitive clip. Conclusion. The restriction of the working angle may compromise the safety of the surgery. It is important to determine the specific indications for this access, particularly in cases of incidental aneurysms.

Microsurgical clipping of a ruptured A1 segment aneurysm.

Background:Proximal anterior cerebral artery aneurysms are usually rare small aneurysms, mostly arising at the origin of perforating arteries on the A1 segment. They account for <1% of all intracranial aneurysms and may be treated by microsurgical or endovascular procedures. The microsurgical approach requires careful evaluation of the imaging. The 3D configuration and orientation of the aneurysm related with the anatomical landmarks (optic chiasm and the adjacent structures of the skull base) might be useful for the navigation. The dominancy, length, deep, and course of the ipsilateral A1 are also important features for planning the temporary and definitive clipping. The presence of vascular abnormalities and space-occupying hematoma should be also evaluated. Intraoperatively, the identification of the medial lenticulostriate branches and the recurrent artery of Heubner, which can originate from the distal A1 in around 10% of cases, might be essential aiming to carry a safe procedure.Technique:The patient was placed in supine position. The head, positioned above the cardiac level, was slightly rotated (20°–30°) and tilted to the opposite side with minimal extension. A right lateral supraorbital approach followed by a frontal ventricular drainage was applied to reduce intracranial pressure before dura opening. Intradurally, the carotid cistern was opened to release some extra cerebrospinal fluid (CSF) and to expose the internal carotid artery bifurcation and the A1 segment. Once, some surrounding adherences and clots indicated the probable location of the aneurysm, a temporary clip was applied on the proximal A1 segment to facilitate the dissection of the aneurysm base, the A1 artery, and the evolved perforators. A ruptured aneurysm arising at the origin of an aberrant fronto-orbital artery was discovered. Initial pilot clip was applied in the aneurysm base and the temporary clip was released. With a controlled aneurysm and after a careful vascular dissection, a definitive clip was placed under temporary trapping. After careful evaluation of some residual neck, a second definitive clip was applied under the first one by a double-clip technique. Intraoperative angiography determined complete occlusion of the aneurysm. The orbitofrontal branch was occluded as well, and small pieces of surgicel embedded in papaverine were applied over its surface. Finally, after opening the lamina terminalis, an external third ventriculostomy was placed for additional CSF removal, replacing the frontal external ventriculostomy.Conclusion:Skillful microneurosurgery is required for the management of challenging small ruptured A1 segment aneurysms.Videolink:http://surgicalneurologyint.com/videogallery/ruptured-a1-aneurysm

Anterior clinoidectomy for paraclinoid aneurysms in Helsinki Neurosurgery.

Background:In this video abstract, we present an intradural anterior clinoidectomy for management of some paraclinoid aneurysms. Quick adenosine cardiac arrest performed instead of an anterior clinoidectomy and proximal temporary clipping usually allows us a proximal control of aneurysms in Helsinki Neurosurgery. However, when the neck of the aneurysm remains hidden under the anterior clinoid process, or when some complex aneurysms have reduced space for placing temporary clips obstructing the definitive clipping, anterior clinoidectomy is the most available option.Technique:The patient with multiple intracranial aneurysms had a ruptured anterior cerebral artery aneurysm associated with a right middle cerebral artery aneurysm and a right small paraclinoid aneurysm. The patient underwent surgical clipping of all aneurysms by a right lateral supraorbital approach at one-stage surgery. After the associated aneurysms were clipped, the hidden paraclinoid aneurysm required an anterior clinoidectomy for definitive clipping. A small durotomy over the anterior clinoid process was made with microscissors after bipolar coagulation. Subsequently, the anterior clinoidectomy was performed under visual control with the use of an electric high-speed diamond drill (3 mm diameter). The direction and size of the drilling were performed according to the anatomical configuration and exact location of the aneurysm determined by the preoperative radiological analysis of the case. A definitive clip was applied after complete visualization of aneurysm. Postoperative computed tomography angiography demonstrated absence of complications.Conclusion:Anterior clinoidectomy is a useful procedure aiming at a proper definitive clipping of paraclinoid aneurysms with challenging locations and configurations.Videolink:http://surgicalneurologyint.com/videogallery/right-clinoidectomy/

Infrared thermography brain mapping surveillance in vascular neurosurgery for anterior communicating artery aneurysm clipping.

Background:Infrared thermography (IT) is a noninvasive, real-time diagnostic method that requires no contact with the patient and has a broad spectrum of potential applications in neurosurgery. It has been previously demonstrated the high sensitivity and specificity that IT has to detect brain blood flow changes.Case Description:The case is based on a 64-year-old diabetic and hypertensive male, to whom an anterior communicating artery (ACoA) incidental aneurysm was discovered. We performed the basal infrared thermography mapping (ITM) and immediately after the transitory clip placement in both A1 segments of the anterior cerebral artery (A1-ACA), we performed a second ITM of the exposed brain cortex. After the definitive clip placement in the neck of the ACoA aneurysm, we removed the transitory clips of both A1-ACA and performed a third ITM of the cortical surface, without finding any cortical cooling or significative temperature differences (Ϫt) compared to the basal ITM. The postoperatory computed tomography (CT) and angio-CT did not show any ischemic damage and confirmed the accurate aneurysm clipping.Conclusions:The ITM seems to be a real-time, safe, and useful brain mapping method to identify different temperature zones and temperature dispersion gradients in the human brain cortex. More studies are needed to evaluate the potential applications of IT mapping of the human brain and its use in neurosurgery and vascular neurosurgery.

Monitorización del flujo sanguíneo regional cerebral mediante la flujometría por difusión termal. Descripción de 3 casos

Cerebral blood flow is the most important physiologic parameter in the setting of brain injury. A regional measurement of the flow (rCBF), can be obtained using continuous methods such as thermal diffusion flowmetry (TD-rCBF). This technology of monitoring allows us to detect and quantify ischemic events related with the temporary artery clipping or malposition of the definitive clip and in patients who have suffered a subarachnoid hemorrhage (SAH) or a traumatic brain injury. Likewise, the precocious detection of ischemic events might help us to adopt more rapidly therapeutic measures and more efficienty.Three cases show during aneurysm clipping procedures and at intensive care: the effects of different hypnotics on TD-rCBF values; the relationship between TD-rCBF and somatosensory and motor evoked potentials; and changes in TD-rCBF and transcranial Doppler ultrasonography (TDU) during a vasospasm.TD-rCBF showed in real-time flow variations induced by anaesthetics and detected changes of CBF earlier than evoked potentials and TDU.

Monitoring of brain oxygenation in surgery of ruptured middle cerebral artery aneurysms

Background:The occurrence of brain ischemic lesions, due to temporary arterial occlusion or incorrect placement of the definitive clip, is a major complication of aneurysm surgery. Temporary clipping is a current technique during surgery and there is no reliable method of predicting the possibility of ischemia due to extended regional circulatory interruption. Even with careful inspection, misplacement of the definitive clip can be difficult to detect. Brain tissue oxygen concentration (PtiO2) was monitored during surgery of middle cerebral artery (MCA) aneurysm presenting with subarachnoid hemorrhage (SAH), for detection of changes in brain oxygenation due to reduced blood flow, as a predictor of ischemic events, during temporary clipping and after definitive clipping.Methods:PtiO2 was monitored during surgery of 13 patients harboring MCA aneurysms presenting with SAH, using a polarographic microcatheter (Licox, GMS, Kiel, Germany) placed in the territory of MCA.ResultsA decrease in PtiO2 values was verified in every period of temporary clipping. Brain infarction occurred in 2 patients; in both cases, there was a decrease in PtiO2 greater than 80% from basal value, a minimum value of less than 2 mmHg persisting for 2 or more minutes during temporary clipping, and an incomplete recovery of PtiO2 after definitive clipping. In 2 patients, incomplete recovery of values after definitive clipping led to verification of inappropriate placement and repositioning of the clip.Conclusion:The results suggest that intraoperative monitoring of PtiO2 may be a useful method of detection of changes in brain tissue oxygenation during MCA aneurysm surgery. Postoperative infarction in the territory of MCA developed in cases with an abrupt decrease of PtiO2 and a very low and persistent minimum value, during temporary clipping, and an incomplete recovery after definitive clipping. Verification of clip position should be considered when there is an incomplete recovery or a persistent fall in PtiO2 after definitive clipping.

Monitoring of brain tissue oxygenation in surgery of middle cerebral artery incidental aneurysms

Introduction:The management of incidental unruptured aneurysms remains a matter of controversy; middle-sized or large anterior circulation incidental aneurysms, in young or middle age patients, should be considered for treatment. Surgical clipping is an accepted treatment for middle cerebral artery unruptured aneurysms. Ischemic events can occur even in cases of incidental aneurysm surgery. Since regional cerebral blood flow can be compromised due to temporary arterial clipping or to incorrect placement of defi nitive clip, we performed intra-operative monitoring of brain tissue oxygen concentration (PtiO2), to detect changes in brain oxygenation due to reduced blood fl ow, eventually leading to ischemia, during surgery of middle cerebral artery incidental aneurysms.Methods:PtiO2 monitoring was performed during surgery of eight patients harboring incidental MCA aneurysms, using a polarographic microcatheter (Licox, GMS – Kiel, Germany), placed in the temporal lobe on the side of the lesion, from dural opening to dural closure.Results:Basal values varied between 2.3 and 27.3 mmHg; these values are lower than those previously described in the literature as “normal” for uninjured brain or in cases of subarachnoid hemorrhage. In all patients, a significant decrease in PtiO2 was found in every period of temporary clipping of MCA. Post-operative infarction in the territory of middle cerebral artery occurred in one patient and, in that case, there was a persistent minimum value of 0.6 mmHg, without recovery after the placement of the definitive clip. In another patient, an incorrect placement of the definitive clip could be predicted by a decrease in PtiO2 value.Conclusions:PtiO2 monitoring during aneurysm surgery shows brain tissue perfusion in real time and there is a correlation between any episode of reduced blood flow to the affected vascular territory during surgery and a decrease of PtiO2 values. Unexpected low basal values were obtained in “uninjured” brain, with no influence from subarachnoid hemorrhage. The values of risk for brain infarction during temporary arterial occlusion still need further studies, but an incomplete recovery or a persistent fall in PtiO2 values after definitive clipping should be considered as an indication for verification of the position of the clip.

Flujometría por difusión termal para la medida del flujo sanguíneo cerebral regional en la cirugía de los aneurismas cerebrales

the thermal diffusion flowmetry (TDF) is a technique that allows the measurement of the regional cerebral blood flow (rCBF) through an implanted microprobe in a cerebral region of interest. The monitoring is continuous, real-time and quantitative (ml/100g/min). The purpose of our clinical work has been to show the technical details and preliminary results by using this monitoring technique during the microsurgical management of cerebral aneurysms and along the postoperative period. The aim of the monitoring of the rCBF is to identify and evaluate ischemic events related with the temporary artery clipping or malposition of the final clip. a total of five patients have been monitored (4 woman and one man with an average age of 50.8 years). Two patients harboured one aneurysm in the middle cerebral artery, other two patients had two aneurysms each one on the internal carotid artery in the exit of the posterior communicating and anterior choroidal artery and the fifth harboured a paraclinoid internal carotid artery aneurysm. All patients were operated on using standard microsurgical techniques through a pterional approach. Surgery was done under neurophysiological monitoring and direct microdoppler fluometry assesment. Just before craniotomy the TDF microprobe was inserted 2.5 cm deep into the white matter through a small burr-hole placed on the coronal line and 2 cm away the midline to measure in the anterior cereral artery vascular sector and 6cm away of the midline to measure in the middle cerebral artery territory. Patients were under continuous monitoring during surgery and along the postoperative period in the recovery unit. A total of 14 temporary artery clippings (between 2-4) with an average total clipping time of 7.2 minutes (ranging 1.6 to 16) and 16 definitive clip replacements (ranging 2 to 8) were done at surgery. Patient with paraclinoid aneurysm was operated on using the retrograde aspiration technique and the internal carotid artery was kept closed 45 mimutes. keeping Some illustrative cases and demonstrative records are presented. the use of TDF allows a quantitative real-time measurement of the rCBF in the areas of interest monitored during the microsurgical management of the cerebral aneurysms which leads to detect ischemic events helpping to avoid ischemic sequelae. The detection of ischemic events in real time would make possible the use of therapeutic measures ealier and more efficienty.

Wartime Traumatic Aneurysms

Operation Iraqi Freedom has resulted in a significant number of closed and penetrating head injuries, and a consequence of both has been the accompanying neurovascular injuries. Here we review the largest reported population of patients with traumatic neurovascular disease and offer our experience with both endovascular and surgical management. A retrospective analysis of all military casualties returning to the Walter Reed Army Medical Center and the National Naval Medical Center, Bethesda, Maryland, from April 2003 until April 2008 was performed. All patients undergoing diagnostic cerebral angiography during their inpatient stay were included in the study. A total of 513 war trauma-related consults were performed from April 2003 to April 2008, resulting in the evaluation of 408 patients with closed and penetrating head injuries. In this population, 279 angiographic studies were performed in 187 patients (25 closed craniocervical injuries, 162 penetrating craniocervical injuries), resulting in the detection of 64 vascular injuries in 48 patients (26.2% of those studied, 34% prevalence). Vascular injuries were characterized by traumatic intracranial aneurysms (TICAs) (n = 31), traumatic extracalvarial aneurysms (TECAs) (n = 19), arterial dissections (n = 11), and arteriovenous fistulae (n = 3). The average TICA size on admission was 4.1 mm, with an observed increase in aneurysm size in 11 cases. In the TICA/TECA group, 24 aneurysms in 23 patients were treated endovascularly with either coiling or stent-assisted coiling, resulting in preservation of the parent artery in 12 of 24 vessels (50%). The injuries in 3 patients in this group progressed despite endovascular treatment and required definitive clip exclusion. Thirteen additional aneurysms in 8 patients were treated surgically, resulting in parent artery preservation in 4 cases (30.8%). Eleven of the 13 remaining TICAs/TECAs resolved spontaneously without treatment. A total of 6 aneurysm ruptures (average size, 8.25 mm) occurred, resulting in 3 deaths. Four of 6 ruptures occurred in TICAs in which the interval size increase was noted angiographically. The management of traumatic vascular injury has evolved with technological advancement and the willingness of the neurosurgeon to intervene. Although open surgical intervention remains a viable solution, endovascular options are available and safe and can effectively temporize a patient while acute sequelae of serious head injury resolve.

Temporary Clipping in Intracranial Aneurysm Surgery

The intra-operative rupture of intracranial aneurysms (IA) occurs in 5–30% of cases as reported in the literature. This event is frequently associated with an increase in mortality and morbidity. The aim of this study was to evaluate the prognostic importance of temporary clipping in intracranial aneurysm surgery. A series of 304 cases of IA treated surgically were selected by excluding giant or Hunt-Hess grade &gt;3 aneurysms. Two groups of patients were compared: one of 157 cases that had temporary clipping (TC) during surgery and the other of 147 patients who did not have TC. The neuroprotective measures used were the infusion of Thiopental and maintenance of adequate blood pressure by use of Bitartrate Metaraminol and Ephedrine. The surgical complications, chiefly intra-operative rupture of the sac and consequences of malpositioning the clip with associated clinical complications, were considered. The two groups were compared using χ2 that showed a statistically significant reduction of the surgical complications in those patients who had TC. The associated poor clinical outcome was reduced from 7.5% to 2.5%. The main prognostic factor in determining the ischemic damage was the occlusion time of the local arterial circulation. The mean occlusion time in these patients was limited to four minutes and in only 12 cases reached 15–16 minutes without ischemic complications. Temporary clipping reduces the risk of intra-operative rupture of aneurysm and permits a better dissection of the sac with an adequate positioning of the definitive clip. In cases of small aneurysm with an easily accessible neck (that predict a temporary occlusion of the local arterial circulation) we consider the maintenance of optimal blood pressure very important. However we do not consider it essential to use electrophysiologic monitoring or other particular techniques of neuroprotection (which are vital in the surgery of giant or complex aneurysms).

Cerebral blood flow and tissue oxygenation monitoring during aneurysm surgery

Regional cerebral blood flow may be compromised during aneurysm surgery. This may occur during vessel occlusion by temporary clips or result from malposition of the definitive aneurysm clip. Post-operative cerebral vasospasm may also compromise cerebral blood flow and is an important cause of morbidity. This study addresses the need for a sensitive indicator of compromised cerebral function during aneurysm surgery by measuring brain tissue oxygenation and laser Doppler flow. Four patients were studied, all of whom had ruptured middle cerebral artery aneurysms. Brain tissue oxygenation measurements were made with a closed polarographic sensor placed in the ipsilateral cerebral hemisphere to the aneurysm. A laser Doppler flow probe and intracranial pressure monitor were similarly placed. The data were simultaneously processed using multimodality recording monitoring. The monitoring was continued during the postoperative period and totalled over 190 hours. Data were analysed as specific events and as trends. Initial tissue oxygen levels were low but improved in all cases as the intracranial pressure was reduced. This effect was independent of the cerebral perfusion pressure. Laser Doppler flow provided an indicator of compromised brain function and tissue oxygenation an indicator of established ischemia. [Neural Res 1998; 20 (Suppl 1): 544-547]

Clipping of an aneurysm 20 years after encasement with methyl methacrylate

A variety of agents have been used to coat aneurysms as an alternative to clipping. These agents were employed more frequently prior to the routine use of the operating microscope and the presently available variety of aneurysm clips. One such coating agent is methyl methacrylate. This report describes a patient with an anterior communicating aneurysm that rebled 20 years after being encased in methyl methacrylate. At operation, the pulsating aneurysm had eroded the adjacent layer of methyl methacrylate, creating a small intervening space. This space allowed removal under the microscope (with a high-speed air drill and a diamond bit) of the methyl methacrylate from the anterior cerebral arteries and aneurysm, exposing it for definitive clip placement. The feasibility of clipping encased aneurysms is discussed.