Tool-Tissue Interaction Forces in Brain Arteriovenous Malformation Surgery.
OBJECTIVE
Surgical resection of a brain arteriovenous malformation (AVM) poses a technical challenge because of the fragility and number of small feeding and draining vessels around the nidus. Acquiring knowledge of the optimal force applied to such tissue is important in surgical performance and education.


METHODS
A force-sensing bipolar forceps was developed through installation of strain gauge sensors, and force profiles were obtained from 2 AVM surgeries. The force data associated with vessel injury, unsuccessful trial, was compared with that from successful trials. Receiver operating curve analysis was used for determining optimal force threshold and evaluating the discriminative accuracy of measurement.


RESULTS
Force data from 519 trials was collected, of which 16 (3.1%) were unsuccessful. The mean and maximum forces in successful trials were 0.23 ± 0.06 N and 0.35 ± 0.11 N compared with unsuccessful trials of 0.33 ± 0.05 N and 0.53 ± 0.11 N, respectively (P < 0.001). There was a strong association of mean and maximum force peaks with unsuccessful trials as reflected by the area under the curve of 0.91 and 0.87, respectively. Threshold analysis showed that the rate of unsuccessful trials and error forces tended to increase with surgical time.


CONCLUSIONS
Excessive force at the tool tip may result in injury to fragile vessels during AVM surgery. A quantifiable metric through force sensing instruments can detect and predict the occurrence of such injury. Such an instrument may be ideal for resident training and evaluation.
Department of Clinical Neurosciences and the Hotchkiss Brain Institute, University of Calgary, Calgary AB, Canada; Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Taku
T
Sugiyama
Department of Clinical Neurosciences and the Hotchkiss Brain Institute, University of Calgary, Calgary AB, Canada.
Liu Shi
LS
Gan
Department of Clinical Neurosciences and the Hotchkiss Brain Institute, University of Calgary, Calgary AB, Canada.
Kourosh
K
Zareinia
Department of Clinical Neurosciences and the Hotchkiss Brain Institute, University of Calgary, Calgary AB, Canada.
Sanju
S
Lama
Department of Clinical Neurosciences and the Hotchkiss Brain Institute, University of Calgary, Calgary AB, Canada. Electronic address: garnette@ucalgary.ca.
Garnette R
GR
Sutherland
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods*; D003399:Craniotomy / Q000379:methods; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000000981:diagnostic imaging / Q000601:surgery*; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D018709:Statistics, Nonparametric; D013525:Surgical Instruments; D015898:Tomography Scanners, X-Ray Computed; D016896:Treatment Outcome
Arteriovenous malformation; Bipolar forceps; Education; Force; Tool–tissue interaction