Use of fenestrated aneurysm clips in microvascular decompression surgery. Technical note and case series

/The standard techniques of microvascular decompression (MVD) surgery in which implant materials such as shredded Teflon felt are used may be inadequate in some complex cases. The authors evaluated the use of fenestrated aneurysm clips to maintain transposition of culprit vessels in patients with trigeminal neuralgia (TN) and hemifacial spasm (HFS). The authors conducted a retrospective review of MVD operations in which the culprit vessel was transposed and then maintained in position with a fenestrated aneurysm clip secured in position by suturing it to the dura mater. Among a consecutive series of more than 450 MVD surgeries, the fenestrated aneurysm clip sling was used in eight of the last 100 cases: six for HFS and two for TN. The follow-up period ranged from 1 to 13 months, and complete symptom resolution was noted in seven of the eight patients. No patient exhibited evidence of any surgical complications. This approach can be safely performed in complicated MVD cases such as reoperations and transpositions of long ectatic arteries. To the best of the authors' knowledge this is the first report in which the use of fenestrated aneurysm clips in MVD surgery is described.     

Microsurgical removal of previously placed aneurysm clips and application of new clips for recurrent cerebral aneurysms. Technical note

A technique is described for removing previously placed aneurysm clips and applying new aneurysm clips for the treatment of regrown or reruptured cerebral aneurysms in patients more than 10 years after the original clipping of the aneurysm neck. The adherent tissue covering previously placed clips is cut just on and alongside the clips themselves using a small scalpel. Using the clip applicator, gentle pressure is applied to open the clip blade as little as possible. The aneurysm clip is carefully slid out along the line where the clip blade has resided, and a new aneurysm clip is applied. The procedure was successfully accomplished in four patients. Whereas three of these patients had an uneventful postoperative course, the remaining patient experienced transient right oculomotor nerve palsy and left-sided motor weakness. The present technique is a useful procedure for treatment of regrown or reruptured cerebral aneurysms occurring a significantly long time after initial clipping of an aneurysm neck.     

Duplex scanning after endovascular aneurysm repair: an alternative to computed tomography

Late complications following endovascular aneurysm repair indicate the need for long-term surveillance. Clinical trials involving endoluminal stent grafts have typically used computed tomography angiography as the main imaging modality for surveillance. However, computed tomography angiography exposes the patient to higher levels of ionizing radiation, nephrotoxic agents, and increased cost compared to duplex ultrasound. Duplex ultrasound scanning has been widely used for surveillance of abdominal aortic aneurysms for many years. It is well established and the procedure of choice for noninvasive imaging of the aorta. It offers the advantages of easy access, decreased cost, no radiation exposure, and no nephrotoxicity. There is little controversy about duplex scanning for preoperative patient evaluation or surveillance of patients with small aneurysms. However, the use and reliability of duplex scanning in the evaluation and surveillance of patients following endovascular repair is controversial. This article will discuss the benefits, techniques, and limitation of duplex ultrasound in the long-term surveillance of endografts following endovascular abdominal aortic aneurysm repair.     

Comparison of multislice computed tomography angiography and digital subtraction angiography in the detection of residual or recurrent aneurysm after surgical clipping with titanium clips

Purpose  To determine the diagnostic accuracy of 3D-CTA using volume rendering (VR) in the detection of residual or recurrent cerebral aneurysms after clipping. Material and methods  Between January 2006 and November 2007, 45 patients (20 female, 25 male) with 50 intracranial aneurysms treated using titanium clips were enrolled in this study. IADSA and 3D-CTA were performed within 1 month after surgery in 27 (60%) patients, after 1 year in 12 (26%) patients and after 5 years in six (13%) patients. In blinded fashion, CTA and DSA images were independently interpreted by two senior neuroradiologists with 7 years of experience in vascular diagnostic neuroradiology. The diagnostic performance of MDCTA compared with DSA for the detection of aneurysm remnants was measured by receiver operating characteristic (ROC) analysis. The area under the ROC curve, 95% confidence interval (CI), sensitivity, and specificity were calculated. Results  For the detection of residue–recurrent aneurysm; the sensitivity and specificity of MDCTA were 87.5% (95% CI = 52.9–97.8%) and 97.4% (95% CI = 86.5–99.5%) for the first reader and 87.5% (95% CI = 52.9–97.8%) and 100% (95% CI = 90.8–100%) for the second reader respectively. Receiver operating characteristic (ROC) analysis revealed good diagnostic performance for 3D-CTA (mean area under ROC curve (Az) = 0.98 and 0.99 for the first and the second observer, respectively) The kappa values extracted from the interobserver concordance analysis for agreement observers regarding the use of MDCTA for assessment of a remnant neck was 0.62. Conclusion  Using MDCTA, it is possible to demonstrate the status of intracranial aneurysms after surgical clipping in the immediate postoperative period as well as long-term follow-up with an high sensitivity and specificity when comparing with the findings of DSA.     

Direct repair of a blisterlike aneurysm on the internal carotid artery with vascular closure staple clips. Technical note

Vascular closure staple clips made of titanium were originally developed for microvascular anastomosis. Clinical applications for these clips include arteriotomy closure for carotid endarterectomy, extracranial-intracranial bypass, and dural closure. This is the first report in which vascular closure staple clips have been used successfully for direct repair of a tear on the internal carotid artery (ICA). This report involves a 65-year-old man who presented with sudden onset of headache. Admission computerized tomography scans demonstrated a diffuse and thick subarachnoid hemorrhage in the basal cisterns. Cerebral angiograms demonstrated a broad-based, small bulge on the superomedial wall of the left ICA. Intraoperatively, an extremely thin-walled aneurysm was seen on the segment of the ICA at the C-2 vertebral level. The aneurysm ruptured abruptly, although no surgical manipulation was being performed on the aneurysm itself. After temporary clips were applied on the vessel, a large tear of the ICA was repaired with vascular closure staple clips. Reconstruction with the vascular closure staple clips required only a short period of temporary occlusion of the ICA. Postoperative angiograms revealed reduction of the aneurysm bulge and good patency of the ICA. The postoperative course was uneventful, and the patient has been free of symptoms. The vascular closure staple clipping procedure is useful for urgent repair of an aneurysm tear. This method is a new treatment option for these fragile aneurysms in cases in which other options, such as encircling clips or bypass procedures, may have drawbacks or be impossible.     

Endoscopic endonasal clipping of an unsecured superior hypophyseal artery aneurysm. Technical note

Paraclinoidal aneurysms, especially superior hypophyseal artery (SHA) aneurysms (with medial projection), can be challenging to access via a pterional craniotomy and damage to the optic nerve can occur during surgery. The authors have previously reported on endonasal clipping and aneurysmorrhaphy of a vertebral artery aneurysm following proximal and distal protection of the aneurysm using partial coil embolization. To the best of the authors' knowledge no unprotected aneurysm has been clipped using an endonasal approach. The 56-year-old woman in this report was found to have two unruptured aneurysms: an anterior communicating artery (ACoA) aneurysm and an SHA aneurysm. An endoscopic endonasal, transplanar-transsellar approach was used to successfully clip the SHA aneurysm. Proximal and distal control was obtained endonasally prior to successful clip occlusion of the aneurysm. The ACoA aneurysm was clipped via a pterional craniotomy during the same anesthetic session. This report shows that it is possible to successfully clip a medially projecting, paraclinoidal aneurysm using an endonasal approach. Such cases must be chosen with extreme caution and only performed by surgeons with significant experience with both endoscopic endonasal approaches and neurovascular surgery.     

Retrograde suction decompression of an ophthalmic artery aneurysm using balloon occlusion. Technical note

A large ophthalmic artery aneurysm was ligated using a modification of the retrograde suction technique described by Batjer and Samson. Temporary proximal occlusion of the internal carotid artery was accomplished with a double-lumen balloon catheter, and distal occlusion was performed with a temporary clip. The aneurysm was collapsed by gentle aspiration through the distal lumen of the balloon catheter. This greatly facilitated dissection and clip ligation of the aneurysm.     

Virtual cystoscopy from computed tomography: a pilot study

OBJECTIVE: To assess the feasibility of virtual cystoscopy reconstructed from helical computed tomography (CT) obtained using an intravenous contrast agent, and to correlate the findings with flexible (FC) and rigid cystoscopy (RC) in patients with bladder tumours. PATIENTS AND METHODS: Eighteen patients (16 men and two women, mean age 72 years, range 59-80) with haematuria and found to have a bladder tumour on FC were included in a pilot study. Contrast-enhanced helical CT scans were taken and based on these datasets, virtual cystoscopy (VC) images were reconstructed by a radiologist unaware of the findings at cystoscopy. All patients had RC and a biopsy taken. The VC images were compared with the findings from FC and RC. RESULTS: At FC, VC and RC, 32, 34 and 36 lesions were identified, respectively; 33 (92%) of the abnormal lesions at RC were correctly identified at VC. At VC, all lesions of >4 mm were identified but only one of three <4 mm was seen. There were two false-positive finding at VC; VC correctly identified 17 (94%) of 18 abnormal bladders. Only 25% of the ureteric orifices were seen. Carcinoma in situ and urethral tumours were not visualized. CONCLUSION: CT-based VC has a high sensitivity for detecting bladder lesions and is comparable with FC; it may have a potential role as a single imaging tool for haematuria. Further larger studies are required to assess its clinical role.     

New titanium spacer for cervical laminoplasty: initial clinical experience. Technical note

Many commercially available hydroxyapatite (HA) spacers for cervical laminoplasty have been introduced but have disadvantages such as lack of plasticity, easy cracking, and occasional difficulty in fixation by sutures. Here we present the short-term results of a newly designed titanium spacer (Laminoplasty Basket) in open-door cervical laminoplasty, and evaluated clinically and radiologically. The titanium box-shaped spacer with two arms for fixation was easily inserted and fixed into the laminoplasty space with 4-mm or 5-mm length screws after the posterior cervical arch was repositioned for the canal expansion. Twenty-one patients with cervical myelopathy due to spondylosis or ossification of the longitudinal ligament or developmental narrow canal observed for more than 6 months postoperatively were enrolled in this study. The neurological condition of these patients improved from 9.4 points on the Japanese Orthopaedic Association scale preoperatively to 13.5 points at 6 months after surgery. Postoperative radiological evaluation showed no laminar closure or implant failure and cervical spine curvature was maintained. These results seemed to have no significant difference compared with those using HA spacers. This titanium spacer is a potential substitute for conventional HA or other similar devices in cervical laminoplasty.     

Accuracy and precision study in vitro for peripheral quantitative computed tomography

We evaluated the accuracy and precision of a peripheral quantitative computed tomography (pQCT) scanner, the Stratec XCT-960, using 12 human cadaveric forearms. The accuracy was determined by comparing the total bone mineral content (BMC) with the ash weight (AW). We scanned and ashed three consecutive slices (thickness 2.5 mm) at the standard position (s-position) and at 2.5 mm both proximal and distal to the s-position. The correlation coefficient between the AW and total BMC using slices at the s-position wasr=0.87 with an accuracy error (random component) of 15.5%. The correlation coefficient using all slices wasr=0.90 with an accuracy error of 14.3%. The correlation coefficient improved tor=0.95 with an accuracy error of 9.7% after averaging the results of all three slices for each forearm. The short-term precision error expressed as the coefficient of variation (CV) of bone mineral density (BMD) and BMC was determined by measuring the forearms five times either with repositioning or without repositioning. The CVs with repositioning were 2.77 and 1.15 for total BMD and BMC, 1.85 for trabecular BMD; without repositioning they were 0.29, 0.58 and 0.69 respectively. To further evaluate the influence of positioning, additional scans were performed at 1, 2 and 5 mm proximal, and 1 and 2 mm distal to the s-position. BMD and BMC were greatly influenced by the scan location; for example, the percentage differences in trabecular BMD 1 mm distal and proximal relative to the s-position were 2.5%±5.1% and 0.18%±6.3%, respectively. The Stratec XCT-960 appears to be a moderately accurate and highly precise scanner with potential usefulness for evaluating BMC and BMD of ultradistal radius.     

Primary closure of a cerebrospinal fluid fistula by nonpenetrating titanium clips in endoscopic endonasal transsphenoidal surgery: technical note

Postoperative cerebrospinal fluid (CSF) leakage is one of the most common and aggravating complications in transsphenoidal surgery. Although primary closure of the fistula would be the most desirable solution for an intraoperatively encountered CSF leak, it is difficult to achieve in such a deep and narrow operative field. In this article, the authors report endonasal endoscopic applications of no-penetrating titanium clips to repair a CSF fistula following tumor removal. The AnastoClip Vessel Closure System (VCS; LeMaitre Vascular, Boston, MA) was used for closure of a CSF fistula in endonasal transsphenoidal surgery. In all four patients, CSF leakage was successfully obliterated primarily with two to five clips. There was no postoperative CSF rhinorrhea or complications related to the use of the VCS. Metal artifact by the clips on postoperative images was tolerable. Primary closure of the fistula using the VCS was an effective strategy to prevent postoperative CSF leakage in transsphenoidal surgery. Future application can be expanded to reconstruction of the skull base dura via endonasal skull base approaches.     

Rapid-bolus contrast-enhanced dynamic computed tomography in acute pancreatitis: a prospective study.

The purpose of this prospective study was to determine the clinicopathological significance of necrotic areas demonstrated by rapid-bolus contrast-enhanced computed tomography (CT) in patients with biochemically predicted severe pancreatitis. Although CT necrosis occurred significantly more frequently in patients with clinically severe (ten of 12) compared with mild (seven of 20) pancreatitis (P less than 0.025), seven of 17 (41 per cent) patients with CT necrosis developed clinically mild pancreatitis and six of ten (60 per cent) patients with clinically severe pancreatitis and CT necrosis recovered with conservative management. The site and extent of CT necrosis did not correlate with disease severity. Fine-needle aspiration cytology, operative and post-mortem findings and endoscopic retrograde cholangiopancreatography examinations all strongly suggested that CT necrosis represents true pancreatic necrosis. We conclude that the finding of CT necrosis is not in itself an indication for operative intervention, but that rapid-bolus contrast-enhanced dynamic CT greatly facilitates the planning and execution of surgical therapy.     

Internal carotid artery rotation technique to expose an aneurysm neck: technical note

OBJECTIVE: Full exposure of a neck of an aneurysm is important to obliterate it completely. METHODS: A 51-year-old woman in whom an unruptured aneurysm projecting medially under the optic nerve was incidentally found underwent clipping surgery. The edge of the circumferentially cut distal dural ring was pulled with forceps to rotate the internal carotid artery and to expose the neck of the aneurysm. RESULTS: The neck of the aneurysm was completely obliterated under direct vision. CONCLUSION: This single, neat method exposes the neck of an unruptured paraclinoid aneurysm of the internal carotid artery.