HYPERPARATHYROIDIS M FAISAL GHANI SIDDIQUI MBBS; FCPS; PGDIP-BIOMEDICAL ETHICS; MCPS-HPE PROFESSOR OF SURGERY J I N N A H S I N D H M E D I C A L U N I V E R S I T Y
PREAMBLE Anatomy & physiology of the parathyroid glands Hyperparathyroidism
ANATOMY & PHYSIOLOGY OF THE PARATHYROID GLANDS
PARATHYROID GLANDS -ANATOMY Endocrine glands Situated behind thyroid gland 4 in number Superior glands constant in position and number Inferior glands may; Vary in position May be more than two in number (supernumerary)
PARATHYROID GLANDS -FUNCTION PARATHYROID GLANDS CHIEF CELLS OXYPHIL CELLS PARATHORMONE (PTH) INCREASED CALCIUM LEVEL IN BLOOD
PARATHORMONE -EFFECTS ON CALCIUM Enhances calcium release from bones by stimulating osteoclasts Increases calcium absorption from distal tubules of kidneys In kidneys, converts 25-hydroxy vitamin D into 1,25- dihydroxy vitamin D. This absorbs calcium from intestine Increases phosphate secretion by the kidneys
HYPER- PARATHYROIDISM
HYPERPARATHYROIDISM -increased production of parathormone (PTH) leading to hypercalcemia
HYPERPARATHYROIDISM -CAUSES Primary Secondary Tertiary
PRIMARY HYPERPARATHYROIDISM HYPERPLASIA ADENOMA CARCINOMA INCREASED SECRETION OF PTH & HYPERCALCEMIA
PRIMARY HYPERPARATHYROIDISM HYPERPLASIA ADENOMA CARCINOMA INCREASED PRODUCTION OF PTH
SECONDARY HYPERPARATHYROIDISM CHRONIC RENAL FAILURE REDUCED CONVERSION OF 25-DHCC TO 1, 25-DHCC REDUCED ABSORPTION OF CALCIUM FROM GUT CHRONIC HYPOCALCEMIA PARATHYROID HYPERPLASIA & INCREASED SECRETION OF PTH
TERTIARY HYPERPARATHYROIDISM CHRONIC RENAL FAILURE REDUCED CONVERSION OF 25- DHCC TO 1, 25-DHCC CHRONIC HYPOCALCEMIA REDUCED ABSORPTION OF CALCIUM FROM GUT AUTONOMOUS AFTER RENAL TRANSPLANTATION PARATHYROID HYPERPLASIA & INCREASED SECRETION OF PTH
HYPERPARATHYROIDISM -BIOCHEMICAL CHANGES Raised PTH level Increased serum calcium Decreased serum phosphate Hypercalciuria
HYPERPARATHYROIDISM -CLINICAL FEATURES
HYPERPARATHYROIDISM -CLINICAL FEATURES BONES, STONES, ABDOMINAL GROANS, & PSYCHIC MOANS
HYPERPARATHYROIDISM CLINICAL FEATURES Bones: short stature, bone deformities, abnormal curvature of spine; multiple cysts in jaw, skull, middle phalanges; Stones: stones; nephrocalcinosis Abdominal groans: peptic ulcer, pancreatitis Psychiatric symptoms: mood disturbances, apathy, fatigue, failure to concentrate
Scoliosis: abnormal curvature of the spine
Multiple cysts in the mandible
Plain X-ray skull: multiple cysts (salt-pepper appearance)
X-ray of humerus and hand: peudotumours -osteitis fibrosa cystica
multiple cysts in hand bones
Stone in left kidney in a patient with hyperparathyroidism
Stone in left kidney
HYPERPARATHYROIDISM -INVESTIGATIONS
INVESTIGATIONS Total serum calcium Inappropriate (elevated or normal) PTH levels in the presence of high serum calcium Hypophosphataemia Elevated urine calcium
HYPERPARATHYROIDISM -MANAGEMENT
Surgery is the only curative option! Medical therapies offered in mild cases to make calcium levels suitable for surgery
MEDICAL TREATMENT Low calcium diet Withdrawal of drugs (diuretics) that aggravate hypercalcemia Calcium reducing agents (biphosphonates) Calcium receptor agonist (cinacalcet)
INDICATIONS FOR PARATHYROIDECTOMY Urinary tract calculi Reduced bone density High serum calcium Age < 50 years Deteriorating renal function Symptomatic hypercalcemia
PREOPERATIVE LOCALIZATION OF GLANDS Surgery has high recurrence rate because surgeon fails to identify: an ectopic adenoma not accessible through a cervical incision disease may involve multiple glands Glands therefore should be routinely visualized preoperatively
PREOPERATIVE LOCALIZATION OF GLANDS -HIGH FREQUENCY NECK ULTRASOUND 75 % of enlarged glands identified Non-invasive Cannot visualize mediastinum Ineffective in the presence of nodular goitre Ultrasound scan of parathyroid adenoma at upper pole right thyroid lobe. C, carotid artery; A, parathyroid adenoma; T, right thyroid lobe.
TECHNETIUM-99m-LABELLED SESTA MIBI ISOTOPE SCAN Identifies 75 % of abnormal glands Scans mediastinum
Technetium-sesta mibi scans 15 minutes and 3 hours after injection showing retention of isotope in a left inferior parathyroid adenoma
Mediastinal parathyroid adenoma. (a) Preoperative sestamibi scan with mediastinal adenoma (arrowed). (b) Operative photograph of median sternotomy showing a 4-cm parathyroid adenoma
OPERATIONS Incisions: Targeted small incision approach Bilateral neck exploration using thyroidectomy incision Preoperative injection of technetiumlabelled sestamibi and use of gamma probe to guide exploration Intraoperative PTH measurement to confirm that the source of excess PTH has been excised Targeted parathyroid surgery; a 2-cm incision over left inferior parathyroid adenoma