The Sizer-Dissector for Aneurysm Clip Selection: Technical Note

Abstract OBJECTIVE: Appropriate clip selection frequently becomes a matter of trial and error because of inadequate dissection of the pathway for each clip blade. To facilitate selection of the proper clip size, a series of dissectors have been designed that mimic the exact caliber of each category of Sugita clips. METHODS: Three lines of sizer-dissectors reflecting the wire size of the most commonly used Sugita clips were developed by attaching a single aneurysm clip blade to a rounded microdissector handle. Each sizer-dissector is scaled in millimeters and is available in straight and angled configurations. Once dissection is presumed to be complete, the device is passed through the pathway of the intended aneurysm clip blades, and the clip with the appropriate caliber and length for permanent occlusion is selected. RESULTS: During dissection and clip ligation of 83 aneurysms, the sizer-dissector was used to select the blade length in 16 lesions and the blade caliber in 5 lesions. There were no complications associated with deployment of the device. CONCLUSION: By use of the sizer-dissector before attempting clip placement, clip selection is facilitated, safety is enhanced, and clip wastage is reduced.

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Aneurysm Clips for Durotomy Repair: Technical Note

Operative Neurosurgery ◽

10.1227/01.neu.0000365423.19998.3d ◽

2010 ◽

Vol 66 (suppl_1) ◽

pp. ons-E124-ons-E125

Author(s):

Alexandra D. Beier ◽

Ryan J. Barrett ◽

Teck M. Soo

Keyword(s):

Primary Closure ◽

Cerebrospinal Fluid Leak ◽

Bed Rest ◽

Technical Note ◽

Lumbar Spine Surgery ◽

Aneurysm Clip ◽

Bone Removal ◽

Dural Closure ◽

Fluid Leak ◽

Primary Modality

Abstract Background: Dural injury is a common complication of lumbar spine surgery. Primary closure is the “gold standard.” Objective: This technical note describes a failed primary closure of a durotomy revised using an aneurysm clip. Methods: From 2005 to 2009, 5 patients underwent repair of a durotomy with the use of aneurysm clips. Resolution of the cerebrospinal fluid leak was seen in all patients. An 84-year-old woman underwent a laminectomy with an inadvertent dural tear that was primarily repaired with suture. On postoperative day 8, the patient presented with new incisional drainage. The wound was explored, and the dura had torn around the previous sutured closure. A curved aneurysm clip was used to obtain dural closure. Postoperatively, the patient’s incision remained dry. Results: Microsurgical closure with suture is the primary modality in durotomy repair. Difficulty arises when the dura is friable and multiple small tears are present. Suturing worsens the durotomy. Also, the durotomy is often caused along a bony edge with limited visualization, requiring additional bone removal to suture, therefore risking destabilization of the spine. Conclusion: We describe the application of an aneurysm clip to treat a recurrent durotomy where the standard practice of sutured closure failed. Aneurysm clips offer a quick, safe, and secure manner to close dura without risking spinal destabilization. They offer significant benefit to already torn, friable dura. Postoperatively, patients have no limitations and are therefore prevented from being exposed to additional risks associated with bed rest. Aneurysm clips are cost and clinically effective in the management of dural injuries.

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data a; * significance level; a=0.05; * variance of difference of two observations on the log scale; * sigmaW = within-subjects standard deviation; sigmaW=0.355; s=sqrt(2)sigmaW; total number of subjects (needs to be a multiple of 2); n=58; * error degrees of freedom for AB/BA cross-over with n subjects in total; n2=n-2; * ratio = mu_T/mu_R; ratio=1.00; run; data b; set a; * calculate power; t1=tinv(1-a,n-2); t2=-t1; nc1=(sqrt(n))((log(ratio)-log(0.8))/s); nc2=(sqrt(n))((log(ratio)-log(1.25))/s); df=(sqrt(n-2))((nc1-nc2)/(2t1)); prob1=probt(t1,df,nc1); prob2=probt(t2,df,nc2); answer=prob2-prob1; power=answer*100; run; proc print data=b; run; As an example of using this SAS code, suppose µ = 1, σ = 0.355, α = 0.05 and n = 58. The power (as a percentage) is calculated as 90.4. The required number of subjects to achieve a given power can easily be obtained by trial and error using a selection of values of n. An alternative approach is to use trial and error directly on the sample size n for a given power. For more on this see Phillips (1990) and Diletti et al. (1991), for example. 7.4 Individual bioequivalence As noted in Section 7.1, individual bioequivalence (IBE) is a criterion for deciding if a patient who is currently being treated with R can be

Design and Analysis of Cross-Over Trials ◽

10.1201/9781420036091-17 ◽

2003 ◽

pp. 362-362

Keyword(s):

Standard Deviation ◽

Sample Size ◽

Degrees Of Freedom ◽

Trial And Error ◽

Significance Level ◽

Individual Bioequivalence ◽

Alternative Approach ◽

Within Subjects ◽

Log Ratio ◽

Selection Of

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EVALUATION AND SELECTION OF THE METHOD FOR CONTROL SYSTEM THE WIRE TENSION IN CUT-OUT ELECTRIC EROSION MACHINES

IZVESTIA VOLGOGRAD STATE TECHNICAL UNIVERSITY ◽

10.35211/1990-5297-2021-1-248-47-50 ◽

2021 ◽

pp. 47-50

Author(s):

M. N. Buza ◽

N. O. Butusov ◽

A. S. Voronin ◽

A. G. Alekhin

Keyword(s):

Control System ◽

Wire Tension ◽

Electric Erosion ◽

The Wire ◽

Selection Of

Variants of the electrode tension mechanism in an electric erosion machine are considered in order to ensure a quick change of the electrode thread and the required degree of tension.

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