Correlation of pre-operative imaging findings and parathyroidectomy outcomes support NICE 2019 guidance

Context Pre-operative localisation studies are standard practice in patients undergoing parathyroidectomy for primary hyperparathyroidism (pHPT). The most common modalities are neck ultrasound (US) and sestamibi scanning. However, the nature of pHPT is changing, with imaging increasingly yielding negative results. Numerous studies suggest unlocalised disease is associated with poor outcomes, calling into question whether such patients are best treated conservatively. Objective This study aims to correlate parathyroidectomy outcomes with pre-operative imaging in a single, high-volume institution. Methods Data from a prospectively maintained departmental database of operations performed from 2017-2019 was analysed. All patients undergoing first-time surgery for sporadic pHPT were included. Data collected included patient demographics, pre-operative imaging, surgical strategy, and post-operative outcomes. Results A total of 609 consecutive parathyroidectomies were included, with a median age of 59 years (range 20-87 years). The all-comer cure rate was 97.5%; this was 97.9% in dual localised patients (those with positive US and sestamibi), compared to 95.8% in the dual unlocalised group (those with negative US and sestamibi) (p=0.33). Unilateral neck exploration was the chosen approach in 59.9% of patients with double positive imaging and 5.7% of patients with double negative imaging (otherwise, bilateral parathyroid visualisation was performed). There was no significant difference in post-operative complications between patients undergoing unilateral or bilateral neck exploration. Conclusions Patients with negative pre-operative imaging who undergo parathyroidectomy are cured in almost 96% of cases, compared to 98% when the disease is localised. This difference does not reach statistical or clinical significance. These findings therefore support current recommendations that all patients with pHPT who are likely to benefit from operative intervention should be considered for parathyroidectomy, irrespective of pre-operative imaging findings.

Parathyroid Glands

The parathyroid glands develop from the endoderm: the superior glands from the fourth pharyngeal pouch, and the inferior glands from the third pharyngeal pouch. Parathyroid glands are usually found on the posterior surface of the thyroid gland. Chief cells secrete PTH, which has a half-life of 3 to 6 minutes. Primary HPT is most often asymptomatic and serendipitously found when the serum calcium value is increased on routine testing. The parathyroid glands can be evaluated with US, CT, MRI, or sestamibi scanning. Cervical exploration for primary HPT involves resection of a solitary adenoma in approximately 85% of patients. Injury to the RLN and superior laryngeal nerve does occur.

The CaPTHUS Scoring Model revisited: Applicability from a UK Cohort with Primary Hyperparathyroidism

ABSTRACT Introduction Focused parathyroidectomy for primary hyperparathyroidism (pHPT) in patients with a single positive localizing scan may have an unacceptably high recurrence rate unless intraoperative parathyroid hormone (ioPTH) is used. The CaPTHUS score was previously developed to predict singlegland disease in such instances. We evaluated the accuracy of this model in a cohort of patients with pHPT in the UK. Materials and methods CaPTHUS scores were calculated from prospectively collected data on consecutive patients undergoing surgery for pHPT [(1 point each for: Preoperative calcium ≥3 mmol/L; PTH ≥2 times upper limit; ultrasound (1 point) and sestamibi (1 point) positive for single enlarged gland; concordant positive scans]. Diagnosis of single or multigland disease was confirmed on pathology. Results From June 2007 to October 2011, 324 patients (251 female, median age 66, 10.89) underwent surgery for pHPT guided with ioPTH. Single-gland pathology was observed in 291 (89.8%) patients and multi-gland disease seen in 33 (10.2%). In single-gland disease patients, significantly higher preoperative calcium (p = 0.030) and PTH levels (p = 0.033) were seen with sensitivities of 65.6% for ultrasound and 66.0% for sestamibi scanning. A CaPTHUS score ≥3 was seen in 51.2% of all patients with a positive predictive value (PPV) for single-gland disease of 99.4%. Conclusion A CaPTHUS score ≥3 was accurate at predicting single-gland disease in >50% of patients with pHPT, providing a similar PPV and reducing the need for ioPTH implementation in this population. However, recent conflicting literature suggests the CaPTHUS score may not be universally applicable, local audit is recommended before implementation. How to cite this article James TW, Stechman MJ, Scott- Coombes DM. The CaPTHUS Scoring Model revisited: Applicability from a UK Cohort with Primary Hyperparathyroidism. World J Endoc Surg 2017;9(1):7-12.

Abstract 315: Feasibility of Arteriovenous Fistula Creation After Previous Radial Artery Harvesting for Aortocoronary Bypass

Background: Arteriovenous fistula (AVF) formation remains the procedure of choice in patients requring hemodialysis. The feasibility of AVF creation in the setting of prior radial artery harvesting after aortocoronary bypass remains unknown. This investigation elucidates which patients might be candidates for AVF creation despite prior radial artery harvesting. Methods: A retrospective review was performed on 2,100 patients undergoing hemodialysis access procedures from 2003 to 2010. Of these patients, 11 (0.5%) were identified as having prior radial artery harvesting for aortocoronary bypass. Pre/Post-operative vein mapping, arterial duplex, digital plethysmography, selective angiography, and sestamibi scanning was performed to evaluate the ulnary artery and palmar arch. Patients with evidence suggesting an intact ulnar artery circulation then underwent AVF creation. Results: All 11 patients had an adequate preoperative work up. Seven (64%) of the 11 patients had digital plethysmography suggesting an intact ulnar artery/palmar arch and underwent successful AVF creation. Three (27%) of the patients had a variety of findings precluding successful AVF creation. One (9%) patient with normal preoperative plethysmography developed a steal syndrome requiring revision of the arteriovenous fistula. Conclusions: Successful AVF creation is feasible in patients with prior radial artery harvesting for aortocoronary bypass. The use of preoperative digital plethysmography, selective ulnar artery/palmar arch arteriography and sestamibi scanning to evaluate forearm muscle perfusion may be used as adjuncts to guide a successful intervention.