title: Low-flow and high-flow neurosurgical bypass and anastomosis training models using human and bovine placental vessels: a histological analysis and validation study.
abstract: OBJECTIVE Microvascular anastomosis is a basic neurosurgical technique that should be mastered in the laboratory. Human and bovine placentas have been proposed as convenient surgical practice models; however, the histologic characteristics of these tissues have not been compared with human cerebral vessels, and the models have not been validated as simulation training models. In this study, the authors assessed the construct, face, and content validities of microvascular bypass simulation models that used human and bovine placental vessels. METHODS The characteristics of vessel segments from 30 human and 10 bovine placentas were assessed anatomically and histologically. Microvascular bypasses were performed on the placenta models according to a delineated training module by "trained" participants (10 practicing neurosurgeons and 7 residents with microsurgical experience) and "untrained" participants (10 medical students and 3 residents without experience). Anastomosis performance and impressions of the model were assessed using the Northwestern Objective Microanastomosis Assessment Tool (NOMAT) scale and a posttraining survey. RESULTS Human placental arteries were found to approximate the M2-M4cerebral and superficial temporal arteries, and bovine placental veins were found to approximate the internal carotid and radial arteries. The mean NOMAT performance score was 37.2 ± 7.0 in the untrained group versus 62.7 ± 6.1 in the trained group (p < 0.01; construct validity). A 50% probability of allocation to either group corresponded to 50 NOMAT points. In the posttraining survey, 16 of 17 of the trained participants (94%) scored the model's replication of real bypass surgery as high, and 16 of 17 (94%) scored the difficulty as "the same" (face validity). All participants, 30 of 30 (100%), answered positively to questions regarding the ability of the model to improve microsurgical technique (content validity). CONCLUSIONS Human placental arteries and bovine placental veins are convenient, anatomically relevant, and beneficial models for microneurosurgical training. Microanastomosis simulation using these models has high face, content, and construct validities. A NOMAT score of more than 50 indicated successful performance of the microanastomosis tasks.
authors.affiliation: Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.|Laboratory of Neurosurgery, Irkutsk Scientific Center of Surgery and Traumatology; and.
authors.forename: Evgenii
authors.initials: E
authors.lastname: Belykh
authors.affiliation: Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.
authors.forename: Ting
authors.initials: T
authors.lastname: Lei
authors.affiliation: Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.
authors.forename: Sam
authors.initials: S
authors.lastname: Safavi-Abbasi
authors.affiliation: Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.
authors.forename: Kaan
authors.initials: K
authors.lastname: Yagmurlu
authors.affiliation: Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.
authors.forename: Rami O
authors.initials: RO
authors.lastname: Almefty
authors.affiliation: Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.
authors.forename: Hai
authors.initials: H
authors.lastname: Sun
authors.affiliation: Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.
authors.forename: Kaith K
authors.initials: KK
authors.lastname: Almefty
authors.affiliation: Irkutsk State Medical University, Irkutsk, Russia.
authors.forename: Olga
authors.initials: O
authors.lastname: Belykh
authors.affiliation: Laboratory of Neurosurgery, Irkutsk Scientific Center of Surgery and Traumatology; and.|Irkutsk State Medical University, Irkutsk, Russia.
authors.forename: Vadim A
authors.initials: VA
authors.lastname: Byvaltsev
authors.affiliation: Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Spetzler
authors.affiliation: Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.
authors.forename: Peter
authors.initials: P
authors.lastname: Nakaji
authors.affiliation: Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.
authors.forename: Mark C
authors.initials: MC
authors.lastname: Preul
mesh_terms: D000714:Anastomosis, Surgical / Q000193:education* / Q000379:methods*; D000818:Animals; D002417:Cattle; D005260:Female; D006801:Humans; D019635:Neurosurgical Procedures / Q000193:education* / Q000379:methods*; D010920:Placenta / Q000033:anatomy & histology / Q000098:blood supply*; D011247:Pregnancy; D014656:Vascular Surgical Procedures / Q000193:education* / Q000379:methods*
keywords: ACA = anterior cerebral artery; ICA = internal carotid artery; MCA = middle cerebral artery; NOMAT; NOMAT = Northwestern Objective Microanastomosis Assessment Tool; PICA = posterior inferior cerebellar artery; RA = radial artery; STA = superficial temporal artery; cerebral revascularization; microvascular anastomosis training; neurosurgical training; placenta; surgical practice; surgical simulation; vascular disorders