Is unilateral approach under local anesthesia for parathyroidectomy feasible? A systematic review of literature.

Introduction: Primary hyperparathyroidism (PHPT) is a common endocrine disease especially in postmenopausal women and in older adults, with elevated parathyroid hormone (PTH) levels by parathyroid glands. The main symptoms of PHPT are hypercalcemia, often associated with hypercalciuria, urolithiasis and bone demineralization that results in osteopenia or osteoporosis and increases overall fracture risk. Parathyroidectomy is today the only definitive treatment for patients to prevent worsening of symptoms. Minimally invasive targeted approach for parathyroidectomy can be offered to patients with well-localized disease, and combined with intraoperative PTH monitoring, the success rate reaches 95-97%; with short operative time, low complications rates and decreased hospital costs. To date, minimally invasive parathyroidectomy (MIP) can be performed under local anesthesia and most patients can be discharged on the same day of surgery or the following morning. The aim of this article is to summarize the current evidence of MIP under local anesthesia and its clinical outcomes to assess the effectiveness and safety of this procedure.

Evidence acquisition: We searched PubMed, Embase, Cochrane and Web of Science databases from their date of inception until 30^th May 2024. Inclusion criteria consisted in articles from any country written in English reporting MIP under local anesthesia related clinical outcomes in humans. RCTs, quasi-RCTs, cross-sectional studies, retrospective and prospective cohort studies, case-control studies were included.

Evidence synthesis: We identified 23 eligible studies that included 2470 adults (mostly female asymptomatic) with PHPT; follow-up duration varied from six months to 24 months. All studies were screened for assessments of quality based on Newcastle-Ottawa Scale and the risk of bias based on ROBIN-I of the included studies. The operative time, number of conversions to general anesthesia, hospital stay and complications was respectively: 43.86 minutes, with 114 conversions to general anesthesia, mean hospitalization time was 16.83±8.62 hours and complications reported in 71 patients. Previously of surgery, the abnormal parathyroid gland is localized using multiplexed ion beam imaging (MIBI) plus ultrasound (US) in 12 studies, only MIBI in three studies, thallium-technetium scan plus US in three studies, single-photon-emission computed tomography (SPECT) plus US in one study and a combination of MIBI, US, SPECT, CT and magnet resonance in one study. The mean preoperative value of PTH and serum calcium was 277.44 pg/mL and 11.49 mg/dL respectively; while the mean postoperative value of PTH and serum calcium was 46.18 pg/mL and 9.11 mg/dL respectively. At the definitive histology the most of pathology is adenoma with 542 cases reported, followed by hyperplasia with 35 cases and only 20 cases of carcinoma.

Conclusions: Focused mini-invasive parathyroidectomy under local anesthesia, guided by positive preoperative localization exams and accurate laboratory data, could be a feasible and effective surgical technique to cure primary hyperparathyroidism, with reduced operative time, a small surgical incision, shorter hospitalization stay and a lower occurrence of postoperative complications.