Extended anterolateral transiliac approach to the sacral plexus.

The approach to the sciatic plexus and lateral part of the sacrum is difficult. A subperitoneal anterolateral approach can be extended by sectioning the iliac bone above the acetabulum and lowering it toward the external part of the iliac wing and buttock. This transiliac anterolateral approach exposes the lumbosacral trunk, first sacral foramina and sciatic plexus to the origin of the sciatic trunk. Exposure can be extended upward by subperitoneal lumbotomy, downward by opening the ischiorectal fossa, or outward by trochanterotomy. This approach was used 18 times by one of the authors (FHD) for resection of 13 malignant tumors and 5 plexus releases. Procedure time was 3-6hours, with 500-4,000ml blood loss. The approach systematically enabled surgical objectives to be met. There was 1 septic complication that healed after debridement.

TERTp Mutation Detection in Plasma by Droplet-Digital Polymerase Chain Reaction in Spinal Myxopapillary Ependymoma with Lung Metastases.

BACKGROUND: Spinal myxopapillary ependymoma (SP-MPE) is a subgroup of ependymomas in which after initial gross tumor resection, recurrences occur in more than half of the patients. Anaplastic transformation may also occur and contributes to intraneural and extraneural metastatic dissemination. Extraneural metastases from SP-MPE are rare and worsen the prognosis. In this situation, the noninvasive detection of recurrent somatic mutations in the circulating tumor DNA (ctDNA) from plasma is challenging. Telomerase-reverse transcriptase gene promoter (TERTp) mutation has been identified in a subset of ependymomas with aggressive behavior. CASE DESCRIPTION: We report on a patient with TERTp mutated SP-MPE presenting with an extraneural anaplastic metastatic dissemination after iterative local recurrences. From the initial SP-MPE to pleural anaplastic lesion, TERTp C228T mutation was present with allele frequency varying from 33% to 39%. Interestingly, TERTp mutation was also detected by droplet digital polymerase chain reaction in the plasma with a frequency of 2.1% at the time of pleural metastases, highlighting that ctDNA is released in plasma of patients suffering from SP-MPE with extraneural metastatic dissemination. CONCLUSIONS: Despite the rarity of this evolution, plasmatic liquid biopsy appears to be a useful diagnostic and follow-up tool in a subset of primary brain tumors.

The article critique as a problem-based teaching method for medical students early in their training: a French example using anatomy.

In France, "article critique" became a particular teaching method in the second part of the medical curriculum. It approaches a reading exercise of scientific medical papers similar to that of journal club. It could be compared to reviewing a paper as performed by reviewers of a scientific journal. We studied the relevancy of that teaching method for the youngest medical students. Our questions were about the understanding and the analyzing ability of a scientific paper while students have just learned basic medical sciences as anatomy. We have included 54 "article critique" written by voluntary students in second and third years of medical cursus. All of the IMRaD structure items (introduction, materials and methods, results and discussion) were analyzed using a qualitative scale for understanding as for analyzing ability. For understanding, 89-96% was good or fair and for the analyzing ability, 93-100% was good or fair. The anatomical papers were better understood than therapeutic or paraclinical studies, but without statistical difference, except for the introduction chapter. Results for analyzing ability were various according to the subject of the papers. This teaching method could be compared to a self-learning method, but also to a problem-based learning method. For the youngest students, the lack of medical knowledge aroused the curiosity. Their enthusiasm to learn new medical subjects remained full. The authors would insist on the requirement of rigorous lessons about evidence-based medicine and IMRaD structure and on a necessary companionship of the students by the teachers.

Vascular anatomical basis of clavicular non-union.

The middle third of the clavicle is commonly involved in any injury and account for 5-10% of all fractures in adults. Although non-unions are rare, their treatment has not been well defined yet. This report describes the arterial supply of the clavicle to clarify the pathological mechanism and the surgical procedure of non-unions. This study was based on delineation of the thoraco-acromial and suprascapular arteries with colored latex on 17 specimens (ten cadavers). Observations were made after macroscopic dissection and maceration. The main blood supply to the middle third of the clavicle was the periosteal. This supply came from the two branches of the thoraco-acromial trunk that penetrated the pectoralis major muscle and the deltoid muscle. In 13 cases, these two periosteal branches were anastomosed between these two muscle attachments. Periosteal vascularization was always seen on the superior surface and the anterior border of the bone, but never on the inferior surface or the posterior border. The suprascapular artery contributed to supply the middle third of the clavicle by several periosteal branches and also by an independent branch. This branch was born proximally near the internal, middle thirds union and passed along the posterior face of the subclavius muscle and pierced the bone through the nutria foramina located near the external, middle thirds union. Nevertheless, intraosseous arteries were noted only in four cases. In these cases, they were never more than 2cm long. Our results showed that the periosteal blood supply located between the muscles insertions and the arterial supply from the suprascapular artery could be twice compromised in case of important displacement or severe fracture. If treatments of clavicular fractures or non-unions cannot preserve the periosteal blood supply, bone grafting should be indicated.

Morphometric study of the shoulder and subclavicular innervation by the intermediate and lateral branches of supraclavicular nerves.

BACKGROUND: The supraclavicular (intermediate) and supra-acromial (lateral) branches of supraclavicular nerves contribute to the innervation of the thorax, shoulder, and neck. Despite their clinical and surgical interest, they are not often considered for descriptive anatomy. The goal of this work was to clarify the morphometric knowledge of these two branches and to discuss the clinical relevance of the anatomical features. METHODS: Intermediate and lateral branches of supraclavicular nerves of 14 necks (8 embalmed cadavers) were dissected using magnifying glasses. Macroscopic parameters were measured and nerve relationships were recorded. RESULTS: In 12 cases, the intermediate and lateral branches arose from a common trunk behind the posterior border of the sternocleidomastoideus muscle, at a mean distance of 96 mm (70-137) from the sternal angle. The intermediate branch divided into two or three secondary rami. Its most internal ramus crossed the middle third of the clavicle and its most external ramus crossed the second lateral quarter of the bone. The distance between the two farthest nerve endings of this branch was at mean of 98 mm (85-125). The mean distance of the most distal nerve ending from the clavicle was 46 mm (30-63). The lateral branch divided into two or three rami in eight cases and did not divide in six cases. Its most anterior rami crossed the trapezius muscle at a mean distance from the clavicular insertion of 17 mm (12-24). In 13 cases, these rami ended posteriorly or at the level of the anterior border of the acromion process and in 12 cases, they ended laterally or at the level of the acromion process with a mean distance 10.4 mm (0-24). CONCLUSION: In case of deficiency of these nerves, pain or sensitive deficit can occur without motor trouble. The factors of acute or chronic injury are direct compression, nerve stretching, repetitive stresses, and direct wound. Moreover, several neck or shoulder surgical approaches are dangerous for these nerves.