The changing face of reoperative parathyroidectomy: a single-centre comparison of 147 parathyroid reoperations.

INTRODUCTION: Reoperative parathyroidectomy for persistent and recurrent primary hyperparathyroidism is dependent on radiology. This study aimed to compare outcomes in reoperative parathyroidectomy at a single centre using a combination of traditional and newer imaging studies. MATERIALS AND METHODS: Retrospective case note review of all reoperative parathyroidectomies for persistent and recurrent primary hyperparathyroidism over five years (June 2014 to June 2019; group A). Imaging modalities used and their positive predictive value, complications and cure rates were compared with a published dataset spanning the preceding nine years (group B). RESULTS: From over 2000 parathyroidectomies, 147 were reoperations (101 in group A and 46 in group B). Age and sex ratios were similar (56 vs 62 years; 77% vs 72% female). Ultrasound use remains high and shows better positive predictive value (76% vs 57 %). 99mTc-sestamibi use has declined (79% vs 91%) but the positive predictive value has improved (74% vs 53%). 4DCT use has almost doubled (61% vs 37%) with better positive predictive value (88% vs 75%). 18F-fluorocholine positron emission tomography-computed tomography and ultrasound-guided fine-needle aspiration for parathyroid hormone are novel modalities only available for group A. Both carried a positive predictive value of 100%. Venous sampling with or without angiography use has decreased (35% vs 39%) but maintains a high positive predictive value (86% vs 91%). Cure rates were similar (96% vs 100%). Group A had 5% permanent hypoparathyroidism, 1% permanent vocal cord palsy and 1% haematoma requiring reoperation. No complications for group B. CONCLUSION: Optimal imaging is key to good cure rates in reoperative parathyroidectomy. High-quality, non-interventional imaging techniques have produced a shift in the preoperative algorithm without compromising outcomes.

Video-assisted thoracoscopic surgery for ectopic mediastinal parathyroid adenoma.

Background: Primary hyperparathyroidism (PHPT), caused by an ectopic mediastinal parathyroid adenoma, is uncommon. In the past, when the adenoma was not accessible from the neck, median sternotomy was advocated for safe and successful parathyroidectomy. Video-assisted thoracoscopic surgical (VATS) parathyroidectomy represents a modern alternative approach to this problem. Methods: Information on patients undergoing VATS was obtained from a specific database, including clinical presentation, biochemistry, preoperative imaging, surgical approach and patient outcomes. A comprehensive literature review was undertaken to draw comparisons with other publications. Results: Over a 2-year period, nine patients underwent VATS parathyroidectomy for sporadic PHPT. Five patients had persistent PHPT following previous unsuccessful parathyroidectomy via cervicotomy, and four had had no previous parathyroid surgery. The median duration of surgery was 90 (range 60-160) min. Eight patients were cured biochemically, with no major complications. One patient required conversion to a median sternotomy for removal of a thymoma that had resulted in false-positive preoperative imaging. Conclusion: With appropriate preoperative imaging, multidisciplinary input and expertise, VATS parathyroidectomy is an effective, safe and well tolerated approach to ectopic mediastinal parathyroid adenoma.

Antecedentes: El hiperparatiroidismo primario (primary hyperparathyroidism, pHPT) causado por un adenoma paratiroideo ectópico mediastínico es infrecuente. Hace años, cuando un adenoma no era accesible por vía cervical se propugnaba una esternotomía media para efectuar una paratiroidectomía segura y con éxito. La paratiroidectomía por cirugía toracoscópica asistida por video (video­assisted thoracoscopic surgical, VATS) es una alternativa moderna para el abordaje de esta patología. Métodos: La información de los pacientes tratados con VATS se obtuvo de una base de datos específica, incluyendo presentación clínica, bioquímica, radiología preoperatoria, abordaje quirúrgico y resultados de los pacientes. Se efectuó una revisión extensa de la literatura para efectuar comparaciones con otras publicaciones. Resultados: Durante un periodo de 2 años, 9 pacientes fueron tratados mediante paratiroidectomía por VATS debido a un pHPT esporádico, de los cuales 5 presentaban pHPT persistente después del fracaso de una paratiroidectomía por cervicotomía, mientras que los 4 restantes no habían sido operados previamente de cirugía paratiroidea. El tiempo medio operatorio fue de 101 minutos (rango 60­160). Ocho pacientes se curaron bioquímicamente, sin ninguna complicación mayor. Un paciente precisó conversión a una esternotomía media para extirpar un timoma que había sido un falso positivo en la radiología preoperatoria. Conclusión: La paratiroidectomía por VATS es una intervención efectiva, segura y bien tolerada para la extirpación de un adenoma ectópico mediastínico, siempre y cuando se disponga de radiología preoperatoria adecuada, equipo multidisciplinar y experiencia.

Visualizing Network Traffic to Understand the Performance of Massively Parallel Simulations.

The performance of massively parallel applications is often heavily impacted by the cost of communication among compute nodes. However, determining how to best use the network is a formidable task, made challenging by the ever increasing size and complexity of modern supercomputers. This paper applies visualization techniques to aid parallel application developers in understanding the network activity by enabling a detailed exploration of the flow of packets through the hardware interconnect. In order to visualize this large and complex data, we employ two linked views of the hardware network. The first is a 2D view, that represents the network structure as one of several simplified planar projections. This view is designed to allow a user to easily identify trends and patterns in the network traffic. The second is a 3D view that augments the 2D view by preserving the physical network topology and providing a context that is familiar to the application developers. Using the massively parallel multi-physics code pF3D as a case study, we demonstrate that our tool provides valuable insight that we use to explain and optimize pF3D's performance on an IBM Blue Gene/P system.