Gompel, Jamie J. Van

MRI–Negative Cushing disease is a very difficult disease to treat medically and surgically. In the past, after negative gland exploration, hemihypophysectomy was commonly performed on the localizing side of inferior petrosal sampling. However, this generally resulted in 50% remission/cure rates. Therefore, other techniques have arisen based on the percent chance of microadenoma tumor being present in the gland. Subtotal gland resection is a technique aimed at removing 75% of the gland that results in a similar chance of remission and a 10% chance of pituitary dysfunction. In this video, the authors demonstrate this important technique for MRI–Negative Cushing disease. The video can be found here: https://thejns.org/doi/abs/10.3171/2023.4.FOCVID2320

Abstract Introduction The clival, paraclival, and craniocervical junction regions are challenging surgical targets. To approach these areas, endoscopic endonasal transclival approaches (EETCAs) and their extensions (far-medial approach and odontoidectomy) have gained popularity as they obviate manipulating and working between neurovascular structures. Although several cadaveric studies have further refined these contemporary approaches, few provide a detailed step-by-step description. Thus, we aim to didactically describe the steps of the EETCAs and their extensions for trainees. Methods Six formalin-fixed cadaveric head specimens were dissected. All specimens were latex-injected using a six-vessel technique. Endoscopic endonasal middle and inferior clivectomies, far-medial approaches, and odontoidectomy were performed. Results Using angled endoscopes and surgical instruments, an endoscopic endonasal midclivectomy and partial inferior clivectomy were performed without nasopharyngeal tissue disruption. To complete the inferior clivectomy, far-medial approach, and partially remove the anterior arch of C1 and odontoid process, anteroinferior transposition of the Eustachian–nasopharynx complex was required by transecting pterygosphenoidal fissure tissue, but incision in the nasopharynx was not necessary. Full exposure of the craniocervical junction necessitated bilateral sharp incision and additional inferior mobilization of the posterior nasopharynx. Unobstructed access to neurovascular anatomy of the ventral posterior fossa and craniocervical junction was provided. Conclusion EETCAs are a powerful tool for the skull-base surgeon as they offer a direct corridor to the ventral posterior fossa and craniocervical junction unobstructed by eloquent neurovasculature. To facilitate easier understanding of the EETCAs and their extensions for trainees, we described the anatomy and surgical nuances in a didactic and step-by-step fashion.

Abstract Objective Prospective data on determinants of muscle strength impairment and quality of life in patients with various subtypes and severity of endogenous hypercortisolism are lacking. Design Single-center cross-sectional study, 2019 to 2022. Methods Patients with Cushing syndrome (CS) and mild autonomous cortisol secretion (MACS) were assessed with clinical and biochemical severity scores, muscle function (nondominant hand grip strength and sit-to-stand test), and quality of life (Short Form-36 [SF36] and CushingQoL). Referent subjects were recruited from the local population undergoing abdominal imaging for reasons other than suspected adrenal disorder. Results Of 164 patients, 81 (49%) had MACS, 14 (9%) had adrenal CS, 60 (37%) had pituitary CS, and 9 (5%) had ectopic CS. Median age was 53 years (interquartile range: 42-63 years), and 126 (77%) were women. The SF36 mental component score was similarly low in patients with MACS vs CS, but physical component score was lower in CS when compared to MACS (mean of 34.0 vs 40.5, P = .001). Compared to MACS, patients with CS had lower scores on the standardized CushingQoL (mean of 47.1 vs 34.2, P < .001). Compared to referent subjects, patients with MACS demonstrated reduced muscle strength, similar to patients with CS (mean sit to stand Z-score of −0.47 vs −0.54, P = .822). Clinical severity (r = −0.22, P = .004) but not biochemical severity was associated with sit-to-stand test performance. Conclusions Both patients with overt CS and MACS demonstrate reduced muscle strength and low quality of life. The clinical severity score utilized is associated with both physical and psychosocial components of CushingQoL and with the physical component of SF36.

OBJECTIVE Chordomas are rare tumors from notochordal remnants and account for 1%–4% of all primary bone malignancies, often arising from the clivus and sacrum. Despite margin-negative resection and postoperative radiotherapy, chordomas often recur. Further, immunohistochemical (IHC) markers have not been assessed as predictive of chordoma recurrence. The authors aimed to identify the IHC markers that are predictive of postoperative long-term (≥ 1 year) chordoma recurrence by using trained multiple tree-based machine learning (ML) algorithms. METHODS The authors reviewed the records of patients who had undergone treatment for clival and spinal chordomas between January 2017 and June 2021 across the Mayo Clinic enterprise (Minnesota, Florida, and Arizona). Demographics, type of treatment, histopathology, and other relevant clinical factors were abstracted from each patient record. Decision tree and random forest classifiers were trained and tested to predict long-term recurrence based on unseen data using an 80/20 split. RESULTS One hundred fifty-one patients diagnosed and treated for chordomas were identified: 58 chordomas of the clivus, 48 chordomas of the mobile spine, and 45 chordomas sacrococcygeal in origin. Patients diagnosed with cervical chordomas were the oldest among all groups (58 ± 14 years, p = 0.009). Most patients were male (n = 91, 60.3%) and White (n = 139, 92.1%). Most patients underwent resection with or without radiation therapy (n = 129, 85.4%). Subtotal resection followed by radiation therapy (n = 51, 33.8%) was the most common treatment modality, followed by gross-total resection then radiation therapy (n = 43, 28.5%). Multivariate analysis showed that S100 and pan-cytokeratin are more likely to predict the increase in the risk of postoperative recurrence (OR 3.67, 95% CI 1.09–12.42, p= 0.03; and OR 3.74, 95% CI 0.05–2.21, p = 0.02, respectively). In the decision tree analysis, a clinical follow-up > 1897 days was found in 37% of encounters and a 90% chance of being classified for recurrence (accuracy = 77%). Random forest analysis (n = 500 trees) showed that patient age, type of surgical treatment, location of tumor, S100, pan-cytokeratin, and EMA are the factors predicting long-term recurrence. CONCLUSIONS The IHC and clinicopathological variables combined with tree-based ML tools successfully demonstrated a high capacity to identify recurrence patterns with an accuracy of 77%. S100, pan-cytokeratin, and EMA were the IHC drivers of recurrence. This shows the power of ML algorithms in analyzing and predicting outcomes of rare conditions of a small sample size.