Comparison of Pipeline Embolization and Coil Embolization for the Treatment of Large Unruptured Paraclinoid Aneurysms

The efficacy of flow diversion (FD) in the treatment of paraclinoid aneurysms has been established. The pipeline embolization device (PED) is one of the most commonly used FD devices. Coil embolization is also useful for treating paraclinoid aneurysms. This study aimed to compare the efficacy and safety of PED treatment and coil embolization for large unruptured paraclinoid aneurysms. This was a single-center, retrospective study of large unruptured paraclinoid aneurysms treated endovascularly between 2009 and 2019 (coil embolization between 2009 and 2015, and PED between 2015 and 2019). Cases with a follow-up period of less than 1 year and recurrence after coil embolization were excluded. The treatment outcomes between coil embolization and PED were compared. We investigated 45 patients with 45 large unruptured paraclinoid aneurysms treated by endovascular surgery in our institution. Twenty-four patients were treated with coil embolization and 21 with PED. In the PED group, the device cost was significantly lower (2,770.4 ± 699.5 vs. 1941.2 ± 552.8 [1000 yen], P = 0.03), procedure duration was significantly shorter (155.4 ± 66.7 vs. 95.1 ± 35.4 min, P <0.01), and the numbers of re-treatments were lower than those in the coil embolization group (41.7 vs. 14.3%, P = 0.05). Both PED and coil embolization were effective and safe for large unruptured paraclinoid aneurysms, and their treatment results were similar. The PED is more beneficial because of its lower cost, shorter procedure duration, and fewer retreatments, and is therefore more useful for the treatment of large unruptured paraclinoid aneurysms.     

Coil embolization of overwide and undertall small intracranial aneurysms with double microcatheter technique

Background

Overwide and undertall small intracranial aneurysms remain a challenge for coil embolization. The purpose of this study is to evaluate the feasibility and results of intrasaccular double microcatheter endovascular coil embolization of overwide and undertall small intracranial aneurysms.

Methods

Small (<7 mm), overwide (dome-to-neck ratio [DNR] ≤1.2), and undertall (ASPECT ratio ≤1.2) aneurysms which were treated with double microcatheter technique were selected. For the double microcatheter technique, two microcatheters were selected simultaneously into the aneurysm sac and coil insertion was performed alternatingly. The initial results, ASPECT, DNR ratios, complications, and follow-up results were assessed.

Results

Twenty small (mean, 3.8 mm), overwide (mean DNR, 1.1), and undertall (mean ASPECT, 1.0) aneurysms were treated with the double microcatheter technique. Overall, complete or near complete occlusion was achieved in 19/20 cases. This was achieved with only the double microcatheter technique in 16/20 cases (ASPECT mean, 1.0; DNR mean, 1.1). Adjuvant balloon remodeling was performed in 4/20 cases (ASPECT mean, 0.8; DNR mean, 1.1). The ASPECT ratio was significantly lower in the adjuvant balloon remodeling cases (p?=?0.027). Coiling failed in one patient with both DNR and ASPECT ratio <1.0. Overall, one patient developed a focal visual field defect after the procedure. No other patients developed neurologically significant complications.

Conclusions

Double microcatheter technique may be a safe and effective method for the treatment of overwide and undertall small intracranial aneurysms.     

Neuroradiological Manifestations of Hereditary Hemorrhagic Telangiectasia in 139 Japanese Patients

The purpose of this study is to report the neuroradiological manifestations of hereditary hemorrhagic telangiectasia (HHT). One hundred and thirty-nine Japanese HHT patients (73 men and 66 women, aged 2–78 years) were included in this study. Diagnosis of HHT was based on genetic analysis and/or clinical diagnosis of Curaçao. They included 68 HHT1 and 37 HHT2 patients. Essentially, all patients underwent brain magnetic resonance imaging (MRI) and pulmonary computed tomography (CT). Contrast enhanced studies of brain MRI and hepatic CT were performed in a subset of patients. Catheter cerebral angiography was performed when indicated. Their neuroradiological features were reviewed retrospectively. Various imaging abnormalities were found. Brain arteriovenous malformations (AVMs) were observed in 27/136 patients (19.9%, 21 patients with HHT1 and 1 patient with HHT2). Pulmonary arteriovenous fistulas (AVFs) were found in 73/137 patients (65.2%, 45 patients with HHT1 and 6 patients with HHT2). Cerebral infarction and brain abscess were found in 17 patients and 3 patients with pulmonary AVFs, respectively. T1 high lesions in the basal ganglia suggestive of porto-venous shunts were observed in 51/136 patients (37.5%, 9 patients with HHT1 and 28 patients with HHT2). Hepatic AVMs were observed in 61/136 patients (44.9%, 15 patients in HHT1 and 29 patients in HHT2). Brain AVMs and pulmonary AVFs were more common in HHT1 than in HHT2 (both p < 0.01), but hepatic AVMs were conversely more common in HHT2 than in HHT1 (p < 0.01). In conclusion, HHT patients present with a variety of neuroradiological manifestations, which are related to substantial causes of morbid-mortality in HHT.     

Detection of the microcatheter tip using a novel microguidewire during coil embolization of cerebral aneurysms - technical note -

Detection of the position of the microcatheter tip is important for safe and effective coil embolization of cerebral aneurysms, but is sometimes difficult, especially in the final stage with a high density of embolized coils. We report a new technique to deduce the position of the microcatheter tip using a novel microguidewire during coil embolization of cerebral aneurysms. The novel microguidewire (ASAHI CHIKAI 10; Asahi Intecc, Nagoya, Aichi), with a radiopaque portion of 30 mm, is advanced into the microcatheter until the distal end of the radiopaque portion reaches the coil mass edge at the neck of the aneurysm. The distance between the second marker of the microcatheter and the proximal end of the radiopaque portion of the microguidewire is checked. The position of the microcatheter tip is deduced from the distance and curve of the microguidewire. Microcatheter tips can be easily detected with this technique without complications. This technique is safe, simple, and useful for deducing the position of the microcatheter tip during coil embolization of cerebral aneurysms.     

MicroNester coil for neurointervention

A MicroNester coil (MNC) was developed from the Nester coil with a 0.018-in microcatheter. The most specific feature of the MNC is the extended length of 14 cm. Neurointervention involving the MNC was undertaken in 11 patients. Intervention procedures were transvenous embolization for a dural arteriovenous fistula in 4 patients, transarterial embolization for a dural arteriovenous fistula in 2, parent artery occlusion for a cerebral aneurysm in 4, and stent-assisted embolization for a carotid artery dissection in 1. A push technique through microcatheter was used to deploy the MNCs. The MNCs were successfully placed into the venous sinus lesion, feeding artery, parent artery of the aneurysm, and the pseudoaneurysm. There were no major technical complications resulting in morbidity. The postoperative course was uneventful except in 2 cases in which the occluded vessel recanalized. Use of MNCs was safe and feasible for embolization of cerebrovascular lesions. Fewer coils are required in embolization when using MNCs.     

Long-term Durability of Coil Embolization for Unruptured Aneurysm after Introduction of the Neck-bridge Stent: Comparison between the Pre-stent Era and the Stent Era

More complex aneurysms can be treated by coil embolization with neck-bridge stent assistance. However, concerns about postprocedural ischemic or hemorrhagic complications remain. In this study, we assessed the long-term durability after introduction of neck-bridge stent in the context of coil embolization for unruptured aneurysm by comparing re-treatment and neurological events between the pre-stent and stent eras. Unruptured aneurysms treated by coil embolization between April 2005 and May 2018 were analyzed retrospectively. We divided cases into two groups: the pre-stent era and the stent era. The cumulative rate of re-treatment and neurological events were assessed and compared. During the period, 177 aneurysms were treated in the pre-stent era and 354 aneurysms were treated in the stent era. The median follow-up was 55 months. In the stent era, the dome/neck (D/N) ratio was significantly lower (P <0.001) and the number of aneurysms located at the posterior circulation was higher (P <0.001). A stent was used in 31.92% of cases in the stent era. The cumulative rate of re-treatment was significantly higher in the pre-stent era than it was in the stent era in univariate and multivariate analyses (P = 0.008, P = 0.008, respectively). The cumulative rate of neurological events was not significantly different between the two groups. The re-treatment rate has been improved without increasing neurological complications after introduction of the neck-bridge stent.     

Usefulness of C-stopper Coil for Neurointervention

C-stopper coil (CSC) which are available for 0.018-inch inner diameter microcenter have been used for neurointervention such as transarterial embolization (TAE) of feeding artery. Although various shapes of pushable microcoils have been developed, microcoils are usually short to embolize the lesion and require lots of coils. The most specific feature of CSC is the extended length of 18 cm. To evaluate the usefulness of CSC, we reviewed our experience of CSC. Neurointervention using CSC was performed for 28 patients (31 treatments). Intervention procedures were TAE for dural arteriovenous fistula (AVF) (n = 15), transvenous embolization for dural AVF (n = 4), parent artery occlusion for cerebral aneurysm, dissection and carotid-cavernous fistula (n = 8), TAE for epistaxis (n = 2), and preoperative embolization for tumor (n = 2). CSCs were deployed with push technique through microcatheter. CSCs were successfully placed into the lesion namely feeding artery, venous sinus, parent artery of aneurysm, or dissection. There were no major technical complications resulting in morbidity. Postoperative course was uneventful. No recanalization of the occluded vessel occurred during follow-up. Use of CSCs was safe and feasible for embolization of cerebrovascular lesion.     

Supratentorial cerebral arteriovenous fistulas (AVFs) in children: review of 41 cases with 63 non choroidal single-hole AVFs

Summary Purpose. In this article we explore the various aspects of the supratentorial Single-Hole AVFs (ST AVFs) in children, focusing on their clinical features, angio-architecture, treatment indications and the role and results of endovascular management.Materials and methods. Among 1565 cases of brain AVMs seen at our neurovascular center, 620 cases were seen in the pediatric age group ( to 15 year-old) and 303/620 were non-Galenic brain AVMs. Among 52 brain AVFs found in children, we reviewed 41 pediatric patients with supratentorial single-hole cerebral AVFs (M/F=28/13) with a total of 63 AVFs. Mean age at presentation was 24 months. Four cases had their lesion diagnosed in utero without particular prognostic significance. 17 cases were multifocal with a total of 39 AVFs. The most common clinical presentation leading to diagnosis was cardiac sufficiency in (31.7%), epilepsy (24.4%), macrocrania (14.6%). Venous ectasia (87.8%) and pial venous stenosis (41.5%) were the most frequent angiographic features. There were 11 cases of Hemorrhagic Heriditary Telangiectasia (HHT1) (including two suspicious cases) among the 41 patients (26.8%) and among those 4 cases had single AVFs and 7 cases had multiple AVFs.Results. Thirty-five children were treated in our institution: 34/35 by embolization alone, 1/35 by a combination of embolization and radiosurgery. 32/35 patients were treated with glue alone, 3/35 with coils (2/3 with glue also). A total of 57 separate lesions were treated. On clinical follow up (from 1985–2002, mean 4.2 years), 88.6% of patients proved to be either asymptomatic, improved from previous clinical symptoms or stabilized. 40% of patients had their lesion(s) already completely excluded.Post operative mortality was 5.6% (2/35), permanent neurological morbidity 3% (1/33). Twenty-six of these 33 patients (78.6%) were neurologically normal. 5/33 patients continue to have neurological symptoms or retardation. 2/33 patients died during follow up (1 ischemic stroke from Pulmonary AVF, 1 death despite partial embolisation).Conclusion. Cerebral arteriovenous fistulae are a rare disease, but not infrequently seen in neonates and infants with AVMs. In one fourth of these patients HHT is suspected to be present. The AVFs are always superficial and fed by pial (cortical) arteries. They seldom reveal a hemorrhagic event. They are similar to those encountered in the posterior fossa or spinal cord. Endovascular treatment using NBCA was the treatment modality chosen resulting in a high rate of success and allowing children to grow up normally with no hemorrhages on follow up and no new symptom other than those already present on admission.     

Transluminal stent-assisted coil embolization of a vertebral confluence aneurysm: technique report

BACKGROUND: Recent advances in stent technology have allowed for negotiation of often tortuous posterior circulation intracranial vasculature. Stent-assisted coil embolization is a novel treatment for complex wide-necked aneurysms, as stents provide a buttress that allows for coil deposition while preventing coil herniation into the parent vessel lumen. We describe a case of stent-assisted coil embolization of a complex wide-necked vertebral confluence aneurysm. CASE DESCRIPTION: A 61-year-old woman presented with a Hunt-Hess III, Fisher Grade III subarachnoid hemorrhage secondary to a ruptured vertebral confluence aneurysm demonstrated on angiography. The patient underwent emergent angiography and attempted coiling of a vertebral confluence aneurysm. Because of the aneurysm's complex wide neck and the presence of subclavian steal syndrome, the coils repeatedly herniated into the left vertebral and basilar artery lumina. A flexible coronary stent was deployed across the aneurysm neck, preventing coil herniation and allowing for greater coil deposition. The patient tolerated the procedure and underwent repeat coiling 2 months postoperatively because of mild coil compaction. This resulted in 100% occlusion and the patient is neurologically normal except for a sixth nerve palsy which had been present after the hemorrhage. CONCLUSION: Recent advances in stent technology allow negotiation of the tortuous posterior circulation vasculature. Stent-assisted coil embolization of complex, wide-necked vertebral confluence aneurysms may be an alternative intervention for these surgically challenging lesions.     

Onyx embolization for the treatment of brain arteriovenous malformations

Background  

Onyx has emerged in recent years for the endovascular treatment of brain arteriovenous malformations (AVMs). However, the role of Onyx embolization is still under discussion. We report our initial experiences in the treatment of brain AVMs with Onyx embolization.     

Embolization of wide-necked aneurysms with using three or more microcatheters

Summary Background. A new and relatively simple endovascular technique, in which more than three microcatheters are used for endovascular treatment of cerebral aneurysms for the first time, is described. Method. Eight patients with wide necked aneurysms were successfully treated with detachable coils using the multiple microcatheter technique. Three patients presented with subarachnoid haemorrhage and five were unruptured. The aneurysm locations were superior hypophyseal artery (2), posterior communicating artery (2), middle cerebral artery bifurcation (1), distal anterior cerebral artery (1), basilar artery (1) and vertebral artery (1). The average neck size was 7.4 ± 2.8 mm (3.5–12 mm), average width of the aneurysms was 10.6 ± 5.7 mm (6.2–23 mm) and depth was 8.9 ± 5.8 mm (3–22 mm). Three microcatheters (7 patients) and four microcatheters (1 patient) were introduced and used for coil delivery. Three or four coils were deployed and intermingled to stabilize the whole coil mass as well as to occupy the aneurysmal sac. When a relatively stable coil frame was formed, one coil was detached and subsequent coils were inserted. After the coil mass became more stable, other coils were also detached and all microcatheters were used for subsequent coil deployment. Findings. All aneurysms were successfully treated without complications. Postemboilzation angiograms showed no contrast filling in 5 cases (100% occlusion) and a very small residual neck in 3 cases. There was no procedure related complication. Conclusion. The multiple microcatheter technique can be one technical option for the endovascular treatment of wide necked aneurysms.     

Adjuvant treatment of chronic osteomyelitis of the tibia following exogenous trauma using OSTEOSET?-T: a review of 21 patients in a regional trauma centre

Surgical debridement and prolonged systemic antibiotic therapy are an established management strategy for infection after tibial fractures. Local antibiotic delivery via cement beads has shown improved outcome but requires further surgery for extraction of beads. OSTEOSET^®-T is a resorbable bone void filler composed of calcium sulphate and 4 % tobramycin that is packed easily into bone defects. This is a review of the outcomes of 21 patients treated with OSTEOSET^®-T for osteomyelitis of the tibia. This is a retrospective case note and clinical review. In all cases, the strategy was debridement, with removal of any implants, with excision back to bleeding bone. OSTEOSET^®-T pellets were packed into any contained defects or the intra-medullary canal with further bony stabilisation (n = 9) and soft tissue reconstruction (n = 7) undertaken as required. Intravenous vancomycin and meropenem were administered after sampling with substitution to targeted antibiotic therapy for between 6 weeks and 6 months. The average follow-up was 15 months. Union rate after tibial reconstruction was 100 %. Wound complications were encountered in 52 %: a wound discharge in the early post-operative period was noted in seven patients (33 %) independent of site of pellet placement. In the 14 cases without a wound leak, five developed wound complications (p = 0.06, Fisher’s exact test) either from delayed wound-healing or pin-site infections. One patient developed a transient acute kidney injury and one refractory osteomyelitis. OSTEOSET^®-T is an effective adjunct in the treatment of chronic tibial osteomyelitis following trauma based on the low incidence of relapse of infection within the period of follow-up in this study, but significant wound complications and one transient nephrotoxic event were also recorded.     

Plasma ADMA Predicts Restenosis of Arteriovenous Fistula

Plasma levels of asymmetrical dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide production, correlate with endothelial dysfunction and the development of cardiovascular events in patients with uremia. It is not known whether endothelial dysfunction contributes to the dysfunction of arteriovenous fistulas (AVFs) in hemodialysis patients. Here, we studied the predictive value of baseline plasma ADMA for symptomatic restenosis of an AVF after percutaneous transluminal angioplasty in dialysis patients. We obtained baseline plasma ADMA levels before percutaneous transluminal angioplasty in 100 consecutive patients with dysfunctional AVFs. Patients were followed up clinically for up to 6 mo after angioplasty for recurrent dysfunction. During the 6 mo after angioplasty, 46 patients experienced recurrent dysfunction of their AVF; of these, follow-up fistulography showed restenosis at the same location in 41, new stenosis at different locations in two, and no significant stenosis in three patients. Up to 60% of the patients with high levels of ADMA (>0.910 μM) had target lesion restenosis compared with 25% of those with low levels (<0.910 μM; P < 0.001). In multivariate analysis, plasma ADMA independently nearly tripled the risk for recurrent symptomatic stenosis of an AVF after percutaneous transluminal angioplasty (hazard ratio 2.65; 95% confidence interval 1.33 to 5.28). These results suggest a role for ADMA in the progression of symptomatic restenoses of AVFs after percutaneous transluminal angioplasty and call for preventive strategies that target ADMA and/or endothelial dysfunction to decrease the risk for AVF restenosis.According to recommendations in the National Kidney Foundation Disease Outcomes Quality Initiative (NKF-DOQI) guidelines, creation of native arteriovenous fistulas (AVFs) is preferable to arteriovenous grafts because of their lower morbidity and higher long-term patency.¹ Nonetheless, AVFs are also subject eventually to dysfunction and failure, which is usually caused by stenosis in the venous segment of the fistula. Although percutaneous transluminal angioplasty (PTA) is effective in treating these stenotic lesions, its benefit is attenuated by a high restenotic rate within 6 mo.¹ Several medical, mechanical, and genetic factors have been identified as being associated with functional or anatomic patency of AVFs^2–5; however, the major cause of individual variation in the development of symptomatic restenosis in dysfunctional fistulas remains unknown.Asymmetrical dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) synthase and has been implicated as an important contributor to endothelial dysfunction.^6,7 ADMA is not excreted in patients with ESRD, and its concentration in plasma is two to six times higher than in normal control subjects.⁸ In patients with ESRD, ADMA is correlated with the development of atherosclerosis and cardiovascular events, which suggests that accumulation of ADMA might be an important cardiovascular risk factor⁹; however, the role of ADMA in the restenosis process after PTA of AVFs is not known. We hypothesized that plasma ADMA levels could be related to future development of symptomatic restenosis after PTA for dysfunctional AVFs. This study was then conducted to investigate prospectively the predictive value of baseline plasma ADMA levels for symptomatic angiographically documented restenosis after PTA in a cohort of patients with dysfunctional AVFs.     

Early ultrasonographic evaluation of idiopathic clubfeet treated with manipulations,casts, and Botox?: a double-blind randomized control trial

Background

The manipulations, casts, and Botox^® method for treating idiopathic clubfoot is an alternative non-surgical treatment method. Botox^®-induced reversible muscle paralysis of the gastrocsoleus enables a physician to manipulate and cast the clubfoot in greater dorsiflexion. Ultrasound is incorporated during the early treatment stages to monitor the underlying physiology of the muscle–tendon unit following Botox^®.

Methods

Ultrasonographic evaluation was performed parallel to a double-blind randomized control trial administering Botox^® or placebo to correct clubfoot. Patients underwent two-dimensional ultrasound to monitor the length changes to the gastrocsoleus and Achilles tendon unit at two time points: pre-injection (baseline) and 6 weeks post-blinded injection. Gastrocsoleus and Achilles tendon length measurements were analyzed among placebo, Botox^® and contralateral controls using repeated measures ANOVA.

Results

The baseline gastrocsoleus length of the clubfoot (322.4 pixels) before blinded injection appears shorter than controls (337.5 pixels), but fails to reach significance (p = 0.05). The complex length within each of the three treatment groups displayed no significant change between baseline and 6 weeks. The complex–tendon ratio and muscle–tendon ratio of the Botox^® treatment group was significantly decreased compared to controls (p = 0.049 and 0.042, respectively). Briefly, when expressed as a proportion, an increase in Achilles tendon length and decrease in gastrocsoleus is observed when clubfeet are treated with Botox^®.

Conclusions

Only in the Botox^® treatment cohort did the muscle shrink to uncover tendon (seen as a decreased complex–tendon ratio and muscle–tendon ratio) over the 6-week interval to effectively increase tendon length with respect to the unit as a whole.

Electronic supplementary material

The online version of this article (doi:10.1007/s11832-015-0633-4) contains supplementary material, which is available to authorized users.     

Feasibility of insertion of a microcatheter through a Y-stent in coil embolization of cerebral aneurysms and its detailed geometry by micro-computed tomography

Background

In Y-stent-assisted coil embolization for cerebral aneurysms, open or closed cell stents are used. Different microcatheters for coil insertion are available. We investigated which microcatheter could be navigated into an aneurysm through a Y-stent with different stents.

Methods

Double Neuroform open-cell stents or double Enterprise closed-cell stents were deployed in Y-configuration in a silicon model of a bifurcation aneurysm. Two endovascular neurosurgeons independently tried to navigate an SL-10 microcatheter for 0.010” coils or a PX Slim microcatheter for 0.020” Penumbra coils into the aneurysm through the Y-stent. In addition, we measured lengths of stent pores of the Y-stents with double Enterprise stents deployed in the model by micro-computed tomography.

Results

It was feasible to navigate an SL-10 microcatheter into the aneurysm through the Y-stent with Enterprise or Neuroform stents. Navigation of a PX Slim microcatheter was feasible in the Y-stents only with Neuroform stents. In the Y-stent with double Enterprise stents, the lengths of the second stent pores were significantly smaller than those of the first stent (0.41?±?0.18 mm vs 0.69?±?0.20 mm; P?=?0.008). The SL-10 microcatheter was smaller than approximately 80 % of the stent pores of the first stent and 30 % of those of the second stent. The PX Slim microcatheter was smaller than 20 % of the stent pores of the first stent and 0 % of those of the second stent.

Conclusions

It was feasible to insert an SL-10 microcatheter into the aneurysm through Y-stents with Enterprise or Neuroform stents. Navigation of a PX Slim microcatheter for 0.020” Penumbra coils was feasible in Y-stents with Neuroform stents, but not with double Enterprise stents. The measurements of stent pores by micro-computed tomography supported this feasibility study. These results may be helpful to select appropriate stents and microcatheters in Y-stent-assisted coil embolization, especially in case of retreatments.     

Electrothrombosis of saccular aneurysms via endovascular approach. Part 1: Electrochemical basis, technique, and experimental results

Eleven experimental saccular aneurysms were created on the common carotid artery of swine. Between 3 and 15 days after creation of these aneurysms, they were thrombosed via an endovascular approach, using a very soft detachable platinum coil delivered through a microcatheter positioned within the aneurysm. This detachable platinum coil was soldered to a stainless steel delivery guidewire. Intra-aneurysmal thrombosis was then initiated by applying a low positive direct electric current to the delivery guidewire. Thrombosis occurred because of the attraction of negatively charged white blood cells, red blood cells, platelets, and fibrinogen to the positively charged platinum coil positioned within the aneurysm. The passage of electric current detached the platinum coil within the clotted aneurysm in 4 to 12 minutes. This detachment was elicited by electrolysis of the stainless steel wire nearest to the thrombus-covered platinum coil. Control angiograms obtained 2 to 6 months postembolization confirmed permanent aneurysm occlusion as well as patency of the parent artery in all cases. No angiographic manifestation of untoward distal embolization was noted. Due to the encouraging results of this research, this technique has been applied in selected clinical cases which are described in Part 2 of this study.     

Comparison of the cheese-wiring effects among three sutures used in rotator cuff repair

Purpose:

The goal of this study was to compare the cheese-wiring effects of three sutures with different coefficients of friction.

Materials and Methods:

Sixteen human cadaveric shoulders were dissected to expose the distal supraspinatus and infraspinatus muscle tendons. Three sutures were stitched through the tendons: #2 Orthocord^™ suture (reference #223114, DePuy Mitek, Inc., Raynham, MA), #2 ETHIBOND* EXCEL Suture, and #2 FiberWire^® suture (FiberWire^®, Arthrex, Naples, FL). The sutures were pulled by cyclic axial forces from 10 to 70 N at 1 Hz for 1000 cycles through a MTS machine. The cut-through distance on the tendon was measured with a digital caliper.

Results:

The cut-through distance in the supraspinatus tendons (mean ± standard deviation, n = 12) were 2.9 ± 0.6 mm for #2 Orthocord^™ suture, 3.2 ± 1.2 mm for #2 ETHIBOND* suture, and 4.2 ± 1.7 mm for #2 FiberWire^® suture. The differences were statistically significant analyzing with analysis of variance (P = 0.047) and two-tailed Student''s t-test, which showed significance between Orthocord^™ and FiberWire^® sutures (P = 0.026), but not significant between Orthocord^™ and ETHIBOND* sutures (P = 0.607) or between ETHIBOND* and FiberWire^® sutures (P = 0.103).

Conclusion:

The cheese-wiring effect is less in the Orthocord^™ suture than in the FiberWire^® suture in human cadaveric supraspinatus tendons.

Clinical Relevance:

Identification of sutures that cause high levels of tendon cheese-wiring after rotator cuff repair can lead to better suture selection.     

Potential Risk of Artificial Cerebrospinal Fluid Solution Without Magnesium Ion for Cerebral Irrigation and Perfusion in Neurosurgical Practice

The effect of irrigation with artificial cerebrospinal fluid (CSF) containing various magnesium ion (Mg²⁺) concentrations on vasospastic arteries was investigated in the dog. Cerebral vasospasm was induced by the experimental subarachnoid hemorrhage model in 15 beagle dogs. Cisternal irrigation was performed for 1 hour via a microcatheter placed in the cisterna magna with commercially available artificial CSF (ARTCEREB®) with physiological concentration of Mg²⁺ (2.2 mEq/l) (ACM group, n = 5), ARTCEREB solution without Mg²⁺ (ACR group, n = 5), and ARTCEREB solution with higher Mg²⁺ concentration (5 mEq/l) (ACMM group, n = 5). CSF electrolyte concentrations and the diameters of the basilar and vertebral arteries were measured. In the ACM group, no changes were detected in either CSF Mg²⁺ concentration or arterial diameters. In the ACR group, the CSF Mg²⁺ decreased significantly to 0.8 ± 0.07 mEq/l from the baseline value of 1.4 ± 0.03 mEq/l, and both basilar and vertebral artery diameters were significantly decreased to 0.61 ± 0.18 mm and 0.57 ± 0.23 mm from their baseline values of 0.74 ± 0.22 mm and 0.68 ± 0.17 mm, respectively. In the ACMM group, the CSF Mg²⁺ significantly increased to 2.4 ± 0.15 mEq/l from the baseline value of 1.4 ± 0.05 mEq/l, and both basilar and vertebral artery diameters were significantly increased to 0.84 ± 0.19 mm and 0.90 ± 0.22 mm from their baseline values of 0.71 ± 0.21 mm and 0.69 ± 0.24 mm, respectively. Irrigation with artificial CSF solution without Mg²⁺ causes vasoconstriction of the cerebral artery. Irrigation with artificial CSF with appropriate Mg²⁺ concentration is essential, especially in patients with subarachnoid hemorrhage.