Triological Society Best Practice
Is bilateral exploration still the standard of care for primary hyperparathyroidism?: Outcomes of focused radio-guided parathyroidectomy and bilateral explorations
The authors have no funding, financial relationships, or conflicts of interest to disclose.
Primary hyperparathyroidism (HPT) is a relatively common surgical disease caused principally by single-gland enlargement and hyperfunction. In experienced hands, 95% of patients are rendered normocalcemic after parathyroidectomy, with minimal morbidity. Traditionally, a bilateral neck exploration (BNE) is the technique of choice. However, new methods are continually being explored to further increase the success rate and decrease the morbidity, including intraoperative ultrasonography, methylene blue localization, selective venous sampling, intraoperative intact parathyroid hormone monitoring, sestamibi scanning, four-dimensional computed tomography, and the use of radio guidance. In this Triological Society Best Practice review, we examined the evidence regarding the use of intraoperative radio guidance for parathyroidectomy in primary HPT compared to the use of the traditional BNE procedure.
Recently, there have been multiple studies examining the use of minimally invasive radio-guided parathyroidectomy (MIRP) for the treatment of primary HPT (see Supporting Table I). The authors of this study reviewed the contemporary literature investigating both MIRP and BNE and performed statistical analysis to determine if there was any advantage of one technique.
BNE has been the standard approach for patients with primary HPT. In 2007, Allendorf et al. published a report examining 1,112 cases in which patients underwent BNE for primary HPT. The overall cure rate was reported at 97.4%, with a complication rate of 3.4%. Morbidity included recurrent laryngeal nerve injury, postoperative bleeding, and transient hypocalcemia; there was no mortality. Their study concluded that BNE for primary HPT is still a safe, feasible, and efficacious approach to treatment.
Viad and Pandelidis published a study of 118 patients, of which 111 underwent MIRP for primary HPT. Of these 111 patients, only two were found to have a recurrence, yielding a success rate of 98.2%. They concluded that MIRP was a safe and efficacious procedure, with cure rates that were comparable to those of BNE. Goldstein et al. published a study in 2003 investigating 123 patients with primary HPT. Of these, 112 patients underwent the MIRP procedure. In this study, they reported a long-term success rate of 98% and a complication rate of only 2.7%. They too concluded that MIRP was a safe and effective procedure. However, the gamma probe's utility did not lie in an improved safety profile when compared to BNE, rather it appeared to be more convenient for the surgeon, and the cost was lower, largely due to reduced operative time. In 2005, Satchie and Chen published a study that examined multiple studies using the gamma probe in MIRP. They too found that there was a wide variability of intraoperative localization rates in current studies. Similarly, they concluded that the variability appeared to be due to the surgeons experience with the device. Successful localization rates appeared to increase as the number of patients involved in the study increased.
When the complication rate was compared between MIRP and BNE procedures, there was no statistical significance found based on the random effects model. Table 1 illustrates this analysis. As seen in Table 1, the P value yielded from the random effects model was .0785, indicating no statistical significance. Table 1 presents the data comparison when cure rates between the two procedures were examined. For this study, the random effects model yielded a P value of .0427, indicating that a statistical significance was found. Although there was a statistical significance found between the MIRP and BNE subgroups, it is not possible to directly attribute this statistical significance to the procedure used. This is due to the fact that none of the studies used compared MIRP and BNE concurrently; instead, the studies reviewed compared either MIRP or BNE.
This study did not specifically address the important issue of cost associated with each procedure. However, through the literature review, it appeared that the common consensus was that MIRP was more cost-effective than BNE. Viad and Pandelidis found that the advantages of MIRP included the decreased disruption of normal tissue, smaller incisions, reduced operative times, lower hospital costs, and same-day discharge. Moreover, performing the procedure at an ambulatory center resulted in significant cost savings.
Based on the literature review and statistical analysis, the use of intraoperative radio guidance for parathyroidectomy does not decrease the rate of complications when compared to BNE, and cure rates (eucalcemia) are equivalent between radio-guided parathyroidectomy and bilateral neck exploration. Gamma probe incorporation into unilateral parathyroid exploration may improve rapid localization with more experienced investigators, but there may be a learning curve. Therefore, it is felt that either procedure can be implemented with confidence that the patient will be rendered normocalcemic. However, it should be noted that intraoperative PTH can be used as an adjunct in focused explorations to assure biochemical success.
Finally, when cost is the driving force, MIRP where appropriate (localizable single gland disease) is preferred. By using MIRP, the operator not only reduces the cost to both the hospital and the patient, but importantly, also decreases the time under anesthesia, which decreases the chance of harm to the patient.
LEVEL OF EVIDENCE
In this review, five level 4 (randomized controlled trials) articles were examined.