Corona mortis and pelvic dissection: Understanding the relationship between anatomical structures and bone areas.

Pelvic fractures are becoming increasingly frequent. The gold standard for surgical managements remains open procedures. Despite its excellent biomechanically results, it can lead to many complications. Minimally invasive surgery could reduce these complications. For complex pelvic trauma, extraperitoneal endoscopic technique has never been described. The aim of this study is to determine anatomical landmarks which are useful for endoscopic pelvic ring surgery using an extraperitoneal approach. The second objective is to compare this minimally invasive procedure to expose the bone versus a traditional open approach. After preparing the vessels with latex injections, 10 specimens are dissected alternately, using an endoscopic method (MIS) on one side and an open method on the other side. Both procedures are performed on the same subject. The visualized bone areas are drilled with burr holes. The marked surfaces are measured with photogrammetry. Finally, the data are processed (surface analysis). An extraperitoneal endoscopic dissection that follows anatomical landmarks can be performed. Bone area (mm2 ) visualized by endoscopy was 74 ± 14 (59-94) compared to 71 ± 16 (48-94) by open method. Paired t-test was performed with no significant difference between the two methods. Skin and muscular incisions were significantly lower in the MIS group (5.1, IC95% [4.1; 6.1], p < 0.001). An extraperitoneal endoscopic dissection of the pelvis can be performed. We also find no significant difference between our method and an open traditional approach concerning bone exposure. We offer a holistic approach to treat pelvic fractures by identifying key anatomical structures.

Long-term surgical oncological and functional outcome of large petroclival and cerebellopontine angle epidermoid cysts: a multicenter study.

Cranial nerve (CN) disorders are the foremost symptoms in cerebellopontine angle (CPA) and petroclival area (PCA) epidermoid cysts (EC).The aim of this work was to  assess the long-term surgical results on CN function and tumor control in these patients. We performed a retrospective cohort study about 56 consecutive patients operated on for a CPA or PCA EC between January 2001 and July 2019 in six participating French cranial base referral centers. Sixteen patients (29%) presented a PCA EC and 40 a CPA EC (71%). The median clinical and radiological follow-up was 46 months (range 0-409). Preoperative CN disorders were present in 84% of patients (n = 47), 72% of them experienced CN deficits improvement at the last follow-up consultation (n = 34): 60% of cochlear and vestibular deficits (n = 9/15 in both groups), 67% of trigeminal neuralgia (n = 10/15), 53% of trigeminal hypoesthesia (n = 8/15), 44% of lower cranial nerve disorders (n = 4/9), 38% of facial nerve deficits (n = 5/8) and 43% of oculomotor deficits (n = 3/7) improved or were cured after surgery. New postoperative CN deficits occurred in 48% of patients (n = 27). Most of them resolved at the last follow-up, except for cochlear deficits which improved in only 14% of cases (n = 1/7). Twenty-six patients (46%) showed evidence of tumor progression after a median duration of 63 months (range 7-210). The extent of resection, tumor location, and tumor size was not associated with the occurrence of new postoperative CN deficit or tumor progression. A functional nerve-sparing resection of posterior fossa EC is an effective strategy to optimize the results on preexisting CN deficits and reduce the risk of permanent de novo deficits.

Does 3D stereoscopy support anatomical education?

PURPOSE: The teaching of anatomy in medical education has historically been based on lectures, cadaveric dissections, and illustrated books for students. Stereoscopic 3D videos are now easily accessible via smartphone and affordable for students. This study aimed to investigate whether a 3D stereoscopic instruction video could improve learning over 2D video. METHODS: A prospective controlled study on a single-site was conducted at the University of Angers. Content knowledge was assessed, followed by the presentation of an instructional neuroanatomy video. Participants watched the video in either 3D or 2D format, then they completed an anatomy written test. Pre-video and post-video performances were analyzed with independent t tests on total score, fundamental anatomical knowledge, anatomical relationships and reasoning. RESULTS: 175 subjects completed the study. At baseline, the 3D (n = 91) and 2D (n = 86) groups were similar, in age and class level. 3D and 2D scores were similar in the pre-test session and in the fundamental knowledge post-test (mean 73.2% vs 74.4%, p = 0.37). Average scores for the 3D group were better for the post-test regarding anatomical relationships (mean 86.4% vs. 63.5%, p = 0.004), clinical inference/reasoning (mean 76.8% vs. 67.6%, p = 0.023) and total note (mean 76.8% vs. 67.6%, p = 0.07). Regarding the 3D student's satisfaction questionnaire (n = 91), 70 students (77%) agreed that the stereoscopic video allowed good 3D visualization of anatomical structures. The student enjoyed using the stereoscopic video (n = 75, 82.5%). Most students supported the use of this kind of stereoscopic 3D video in their normal teaching as a complementary tool (n = 78, 85%). CONCLUSIONS: The incorporation of 3D videos as ancillary teaching into curricula could be of interest to improve the knowledge of anatomical relationships and reasoning among students.

[Solitary fibrous tumors and hemangiopericytomas of the meninges: Immunophenotype and histoprognosis in a series of 17 cases]. / Tumeurs fibreuses solitaires et hémangiopéricytomes des méninges : immunophénotype et évaluation du grade histopronostique dans 17 cas.

INTRODUCTION: The 2007 World Health Organization (WHO) classification of tumors of the central nervous system distinguishes meningeal hemangiopericytomas (HPC) from solitary fibrous tumors (TFS). In the WHO classification of tumors of soft tissue and bone, those neoplasms are no longer separate entities since the discovery in 2013 of a common oncogenic event, i.e. the NAB2-STAT6 gene fusion. A shared histopronostic grading system, called "Marseille grading system", was recently proposed, based on hypercellularity, mitotic count and necrosis. We evaluated the immunophenotype and histoprognosis in a retrospective cohort of intracranial HPC and TFS. METHODS: Fifteen initial tumors and 2 recurrences were evaluated by immunohistochemistry for STAT6, CD34, EMA, progesterone receptors and Ki67. The pronostic value of the WHO and the Marseille grading systems was tested on 12 patients with clinical follow-up. RESULTS: Initial tumors were 11 HPC and 4 SFT. STAT6 and CD34 were expressed in 16/17 tumors, EMA and progesterone receptors in 2 and 5 cases, respectively. The Ki67 labelling index was 6.25% in HPC and 3% in SFT. Half of the tumors recurred between 2 years and 9 years after initial diagnosis (mean time 5 years). No statistical difference in the risk of recurrence was associated with either grade (WHO or Marseille), in this small cohort. CONCLUSION: The diagnosis of HPC and TFS is facilitated by the almost constant immuno-expression of STAT6, and this justifies their common classification. The high rate of recurrence implies a very long-term follow-up because the current grading systems do not accurately predict the individual risk.

Self-Assessment Versus Peer-Assessment in Microsurgery Learning: A Comparative Retrospective Study in a Surgery Residents Cohort.

INTRODUCTION: In surgical learning, self-assessment allows the physician to identify and improve his strong and weak points. However, its scientific validity has yet to be demonstrated. The aim of this study was to analyze if there is a link between self-assessment accuracy and improvement in surgical skills. We make the hypothesis that an accurate self-assessment allows a greater improvement MATERIAL AND METHOD: We set up a retrospective cohort study at the tertiary University Hospital of Angers. Between 2019 and 2021, twenty-eight surgery residents took part into a microsurgery program and were included in the study. For two weeks, they performed anastomosis training on inert material and living anesthetized rats under microscope. Each resident was evaluated during the workshop by senior surgeons on 10 items: movement stability and fluidity, instrument manipulation, needles, dissection, clamp setting, vessel manipulation, suture, checking before clamp removal, checking after clamp removal, watertighness. Self-assessment was performed by the residents with the same grid, at the end of the workshop. Residents' and senior's evaluations were double-blind. We retrospectively analyzed the concordance between senior objective assessment and self-assessment, and the effect of an accurate self-assessment on technical improvement. RESULTS: Data for twenty-five residents were analyzed, 14 were female (56%). The mean age was 29 years. Surgical specialties were orthopedics (44%), maxillofacial surgery (45.4%), neurosurgery (12%), gynecology (4%) and vascular surgery (4%). According to Cohen's kappa coefficient, 14 residents (56%) underestimated themselves, 7 (28%) were concordant with peer-assessment and 4 (16%) overestimated themselves. The concordance between self and peer assessment during sessions was positive for the most objective items, and negative for the most subjective items. Technical skills improvement in term of peer-assessment averages was positive for each item in each group, without statistical differences between groups. CONCLUSION: We found that the ability to self-assess in a fast-track microsurgery module for surgery residents varied according to analyzed gestures. We demonstrated an improvement in term of self-assessment for objective items, and a decrease for subjective items. However, we didn't find any relation between improvement curve and the accuracy of self-assessment.

Fast-track teaching in microsurgery.

INTRODUCTION: In France, microsurgery is taught in University diploma courses, for a mean 100hours (range, 45-120hours) extending over several months. This training, spread over the year, encounters problems of maintaining high-quality supervision and enduring acquisition of skills. These difficulties risk leading to withdrawal of certain courses, already suffering from funding issues and administrative requirements for animal welfare. MATERIAL AND METHOD: We report our experience with a 2-week module comprising nine 4-hour sessions (total, 36hours), with continuous supervision of 5 students in each of 2 groups (10 students), enabling personalized learning. At the end of each session, an assessment questionnaire was filled out by teachers and students. RESULTS: Students' scores increased from a mean 23.9/30 points (range, 20 - 30) at session 3 to 26.9 points (range, 23 - 30) at session 9 (p=0.012). At the end of session 3, students were grouped as good, average or beginners, based on the first assessments: i.e., with differences in level between groups at session 3. At the end of session 9, all 3 groups showed statistically comparable levels. Comparison between student and teacher questionnaire responses showed a significant discrepancy in 7 of the 10 cases in week 1, and no significant discrepancy in 7 of the 10 cases by the end of week 2. DISCUSSION: The efficacy of condensed learning is based on immediate repetition of exercises, following Ebbinghaus: without repetition, memory decays exponentially, whereas if the information is rapidly repeated, the curve flattens and memory is consolidated. The present rapid improvement in the acquisition of the principles of microsurgery stimulated the enthusiasm of both students and teachers for what is reputed to be a demanding type of training. The study showed that acquisition, assessed in terms of vascular suture reliability, was achieved by the end of a 36-hour module, regardless of the student's baseline level.

Stereoscopic Surgical Video of Combined Petrosectomy With Virtual Reality Headset: 3-Dimensional Operative Video.

The use of 3-dimensional (3D) videos allows students to visualize surgical procedures from the perspective of the surgeon without missing the essential parts.1 This 3D commented video demonstrates the operative technique and surgical nuances of the combined petrosectomy, visualize using virtual reality headsets. Historically, traditional intradural cisternal routes using suboccipital and pterional approaches have been proposed to remove petroclival tumors.2-5 It allows rapid identification of neurovascular structures and a short exposure time. However, access to the petroclival region is far, not direct, and requires intradural cerebral retraction.6 In order to improve the access for tumoral dissection, lateral transpetrosal approaches have been proposed.7-12 The extradural route shortened the distance to the petroclival region, allows to better preserve the veins, to decrease the cerebral retraction, to interrupt early the tumor vascular supply, and a larger extent of resection.6 Transpetrosal approaches includes middle fossa approach8,10 (removing the petrous apex), posterior petrosal approach9,13,14 (removing of presigmoid retrolabyrinthine bone), and translabyrinthine petrosectomy.12 A combined petrosectomy may be used to approach larger tumor extending across the clival midline, upward to the tentorium or downward to the lower cranial nerves.6,10,15,16 Alternatively, according to Nanda, a retro-sigmoid approach may need to be performed to avoid critical draining veins injury.10,17 Good resection and outcomes are obtained when experienced surgeons use familiar approaches and microsurgical techniques.10.

Clip-first policy versus coil-first policy for the exclusion of middle cerebral artery aneurysms.

OBJECTIVE: Middle cerebral artery (MCA) aneurysms are a particular subset of intracranial aneurysms that can be excluded by clipping or coiling. A comparison of the results between these two methods is often limited by a selection bias in which wide-neck and large aneurysms are frequently treated with surgery. Here, the authors report the results of two centers using opposing policies in the management of MCA aneurysms: one center used a clip-first policy while the other used a coil-first policy, which limited the selection bias and ensured a good comparison of these two treatment modalities. METHODS: All patients treated for either ruptured or unruptured MCA aneurysms at one of two institutions between January 2012 and December 2015 were eligible for inclusion in this study. At one center a clip-first policy was applied, whereas the other applied a coil-first policy. The authors retrospectively reviewed the medical records of these patients and compared their clinical and radiological outcomes. RESULTS: A total of 187 aneurysms were treated during the inclusion period; 88 aneurysms were treated by coiling and 99 aneurysms by clipping. The baseline patient and radiological characteristics were similar between the two groups, but the clinical presentation of the ruptured aneurysm cohort differed slightly. In the ruptured cohort (n = 90), although patients in the coiling group had a higher rate of additional surgery, the complication rate, functional outcome, and risk of death were similar between the two treatment groups. In the unruptured cohort (n = 97), the complication rate, functional outcome, and risk of death were also similar between the two treatment groups, although the risk of discomfort related to the temporal muscle atrophy was higher in the surgical group. Overall, the rate of complete occlusion was higher in the clipping group (84.2%) than in the coiling group (31%), which led to a higher risk in the coiling group of aneurysm retreatment within the first 2 years (p = 0.04). CONCLUSIONS: Clipping and coiling for MCA aneurysm treatment provide the same clinical outcome for ruptured and unruptured aneurysms. However, clipping provides higher short- and long-term rates of complete exclusion, which in turn decreases the risk of aneurysm retreatment. Whether this lower occlusion rate can have a clinical impact in the long-term must be further evaluated.

The Surgeon in Action: Representations of Neurosurgery in Movies from the Frères Lumière to Today.

In this review, we examine the portrayal of neurosurgery and neurosurgeons in 61 movies produced from the beginnings of cinema from the Lumière brothers (1895) to 2017, across 4 continents and covering 10 cinematic genres. We find that these movies tend to shape most beliefs and stereotypes about neurosurgery. However, we notice that there is a trend to describe neurosurgery and neurosurgical disorders with more accuracy as we progress in time. Although it is not for the medical profession to dictate or censor fictional content, a keen eye on these depictions will help us to understand, and perhaps combat, some of the stereotypes and myths that continue to surround neurosurgery in the twenty-first century.

Transdural Spinal Cord Herniation: Tips and Tricks.

Recognition of transdural spinal cord herniation has increased over the past decade. This condition remains little known, particularly outside the specialized fields of spinal surgery and neuroradiology, leading to a significant delay in clinical diagnosis and treatment. It should be considered among the differential diagnoses in patients with gradual-onset lower-limb weakness of presumed spinal origin. Reaching a diagnosis using magnetic resonance imaging is essential to refer patients for surgery before their myelopathy worsens. We describe our surgical experience to untether the spinal cord by wrapping a dura graft around the spinal cord. Three case reports and a review of the literature are discussed.

Lessons to Be Remembered from a Dural Arteriovenous Fistula Mimicking Medulla and High Cervical Cord Glioma.

The radiological signs of intracranial dural arteriovenous fistulas (ICDAVFs) are heterogenous. While it is commonly accepted that hyper intense T2 wedge magnetic resonance imaging of the brainstem and cervical cord mainly concern gliomas, it is so far uncommon and probably unknown that ICDAVFs can imitate similar radiological pattern, especially with gadolinium contrast enhancement and cord enlargement. Thus the angiography is poorly documented in the diagnostic workup. We report the unusual history of ICDAVFs, revealed by clinical and radiological features that mimicked a medulla or cervical spinal cord glioma. This observation provides information on the management of atypical lesions mimicking medulla or cervical cord glioma and arguments for a careful radiological study. Looking for dilated veins around the brainstem and the cord is mandatory in the workup of a supposed infiltrating brainstem or spinal cord lesion, in order to rule out an ICDAVF. Even if the hyperintense T2 images associated with contrast enhancement is in favor of a brainstem or spinal cord glioma, additional cerebral angiography should be mandatory. Moreover, this clinical case highlights the need for a multidisciplinary approach including neuroradiologist, oncologist and neurosurgeon.

The interperiosteodural concept applied to the jugular foramen and its compartmentalization.

OBJECTIVE The dura mater is made of 2 layers: the endosteal layer (outer layer), which is firmly attached to the bone, and the meningeal layer (inner layer), which directly covers the brain and spinal cord. These 2 dural layers join together in most parts of the skull base and cranial convexity, and separate into the orbital and perisellar compartments or into the spinal epidural space to form the extradural neural axis compartment (EDNAC). The EDNAC contains fat and/or venous blood. The aim of this dissection study was to anatomically verify the concept of the EDNAC by focusing on the dural layers surrounding the jugular foramen area. METHODS The authors injected 10 cadaveric heads (20 jugular foramina) with colored latex and fixed them in formalin. The brainstem and cerebellum of 7 specimens were cautiously removed to allow a superior approach to the jugular foramen. Special attention was paid to the meningeal architecture of the jugular foramen, the petrosal inferior sinus and its venous confluence with the sigmoid sinus, and the glossopharyngeal, vagus, and accessory nerves. The 3 remaining heads were bleached with a 20% hydrogen peroxide solution. This procedure produced softening of the bone without modifying the fixed soft tissues, thus permitting coronal and axial dissections. RESULTS The EDNAC of the jugular foramen was limited by the endosteal and meningeal layers and contained venous blood. These 2 dural layers joined together at the level of the petrous and occipital bones and separated at the inferior petrosal sinus and the sigmoid sinus, and around the lower cranial nerves, to form the EDNAC. Study of the dural sheaths allowed the authors to describe an original compartmentalization of the jugular foramen in 3 parts: 2 neural compartments-glossopharyngeal and vagal-and the interperiosteodural compartment. CONCLUSIONS In this dissection study, the existence of the EDNAC concept in the jugular foramen was demonstrated, leading to the proposal of a novel 3-part compartmentalization, challenging the classical 2-part compartmentalization, of the jugular foramen.

Spheno-Orbital Meningiomas Surgery: Multicenter Management Study for Complex Extensive Tumors.

BACKGROUND: Spheno-orbital meningiomas (SOMs) are complex tumors involving the sphenoid wing, the orbit, and sometimes the cavernous sinus with bone hyperostosis and sheet-like dural involvement. Optimal removal, proptosis cure, and visual preservation remain a challenge. OBJECTIVE: To study the management of surgically treated SOMs. METHODS: The clinical records of 130 consecutive patients undergoing surgery for SOMs were retrospectively collected in a database during a 20-year period to analyze symptoms, surgical technique, clinical outcome, and follow-up. RESULTS: Among the 130 patients (mean age 51.2 ± 9.5 years), 91.5% were female. The most typical symptoms recorded were proptosis in 94.6%, visual impairment in 37.7%, and oculomotor paresis in 10.0%. Simpson grade I-II removal was achieved in 97 patients (74.6%). After 1 year, proptosis was improved in 60% of cases. A total of 44.9% of the patients with preoperative visual acuity impairment were improved. Periorbital excision was statistically linked to proptosis decreasing (P = 0.0001) and optic canal decompression was linked to visual stabilization (P = 0.03). Bone reconstruction prevented temporal muscle atrophy (P = 0.01) and unaesthetic results (P = 0.0001). Mean follow-up was 76.5 months (range 3-288 months), and the mean time for recurrence was 54.2 months. CONCLUSIONS: A single-stage optimal surgery with bone reconstruction appears to be the best first-line treatment, on a case-by-case analysis. Optic canal decompression and periorbital excision have to be performed in case of visual disturbance and proptosis. SOMs require a long-term follow-up because of a delayed high rate of recurrence.

Contribution of magnetic resonance cholangiography to the anatomic study of bile ducts.

BACKGROUND/AIMS: Until recently, in-depth anatomic study of the biliopancreatic ducts was only possible with injection-corrosion techniques or peroperative radiology. These were tedious and tributary of the quality of anatomic specimens. Since 1990, a new minimally invasive technique has been available: nuclear magnetic resonance cholangiography (NMRCP). The aim of the study was to evaluate the feasibility and the results of NMRCP applied to the study of the biliopancreatic tract. METHODOLOGY: NMRCP was performed in 50 healthy volunteers and results were interpreted by two readers in consensus. RESULTS: NMRCP showed the common bile, left hepatic and paramedian ducts in 100% of cases. The right hepatic duct was seen in 78% of cases. The lateral duct was seen in 98% of cases. Segmental ducts were found in 68 to 78% of cases for segments II, III, VI, VII and VIII. Only 18% of ducts for segment I were found. The gallbladder was seen in only 72% of cases. The cystic duct was clearly seen in 64% of cases. The hepato-pancreatic duct was seen in 82% of cases. In 70% of cases, distribution of the hepatic ducts was modal. The remaining 30% displayed variations. CONCLUSIONS: The anatomic and radiological results reported in our study of 50 cases demonstrate the excellent feasibility and reliability of magnetic resonance cholangiography applied to the anatomic study of the bile ducts. We suggest that a wide scale multicenter study in living healthy individuals may be worth considering.

An unusual and spectacular case of spindle cell lipoma of the posterior neck invading the spinal cervical canal and posterior cranial fossa.

The authors describe the first case of spindle cell lipoma of the posterior neck invading the upper cervical spinal canal and the posterior cranial fossa. Spindle cell lipoma is an extremely rare variant of benign lipoma. It usually occurs as a solitary subcutaneous well-circumscribed lesion in the posterior neck or shoulders of adult men. Local aggressiveness is unusual. This 61-year-old man presented with an increased left cerebellar syndrome and headaches. He also had a posterior neck tumefaction, which had been known about for a long time. Computed tomography and MR imaging studies revealed a voluminous mass extending to the upper cervical canal and posterior cranial fossa and eroding the neighboring bones. The lesion was well delimited, and contrast enhancement was intense and heterogeneous. The tumor, which had initially developed under the muscles of the posterior neck, was totally resected. Histological assessment revealed numerous fat cells with spindle cells secreting collagen. The large size of the tumor and the submuscular location, bone erosion, and compression of the CNS were unusual in this rare subtype of benign adipose tumor. Its presentation could simulate a sarcoma.

Vestibular schwannomas: complications of microsurgery.

Current microsurgical treatment of vestibular schwannomas usually brings satisfactory results for the patients. However, transient or permanent complications may occur, especially when treating large tumors. Precise information about these potential complications has to be given to the patient at the time of the surgical decision. Based on their personal experience of large operated vestibular schwannomas and analyzing a review of the international literature, the authors detail these complications and the way to prevent and manage them. The problems that are linked to the variety of surgical approaches are also commented. The most frequent complication is cerebrospinal fluid leak that requires medical management and in less than one third of cases, surgical exploration. Vascular problems including ischemia or hemorrhage inside the posterior fossa represent the main source of permanent morbidity. Lower cranial nerve deficits are unusual but may expose to early and delayed aspiration pneumonias. The authors conclude that careful selection of cases, meticulous operative management and intensive postoperative care are essential steps to prevent and to treat these complications.