History of present illness

• a.
  

  Most patients with PHPT are asymptomatic, but many have nonspecific symptoms such as fatigue, weakness of the proximal extremities, diffuse bone pain, anorexia, and constipation.

  
  
• b.
  

  Symptoms of hypercalcemia

  
  
  
  
  • 1)
    

    Urinary system: Polydipsia, polyuria, nephrolithiasis

    
    
  • 2)
    

    Skeletal system: Osteopenia, osteoporosis, or osteitis fibrosa cystic, which presents with bone pain, pathologic fractures, and/or “brown tumors”

    
    
  • 3)
    

    Gastrointestinal system: Peptic ulcer disease (PUD), pancreatitis, cholelithiasis

    
    
  • 4)
    

    Cardiovascular system: Hypertension, arrhythmias, embolic events

    
    
  • 5)
    

    Neurologic system: Depression, anxiety, cognitive dysfunction, psychosis

  
  
  
  
• c.
  

  Symptoms of coexistent thyroid disease

  
  
  
  
  • 1)
    

    Compressive symptoms such as dysphagia, hoarseness, cervical pressure, globus sensation

  
  

Past medical history

• a.
  

  Previous treatment of PHPT

  
  
• b.
  

  History of radiation therapy to the neck

  
  
• c.
  

  Medical illnesses, to determine candidacy for surgery

  
  
• d.
  

  Past surgical history, especially operations on the neck

Family history: Thyroid or parathyroid disease, familial isolated hyperparathyroidism, MEN type 1 or 2A, or familial hypocalciuric hypercalcemia

Medications

• a.
  

  Anticoagulants and antiplatelet medications

  
  
• b.
  

  Lithium or thiazide diuretics

  
  
  
  
  • 1)
    

    May cause mild hypercalcemia and hyperparathyroidism, so discontinue for at least 1 month before confirming PHPT.

  
  
  
  
• c.
  

  Allergies to antibiotics

Neck

• a.
  

  Examination findings are nonspecific

  
  
• b.
  

  Assess for thyroid nodules and cervical adenopathy.

  
  
• c.
  

  A palpable mass in the neck in the patient with hypercalcemia may indicate parathyroid carcinoma.

Laryngoscopy

• a.
  

  Assess preoperative RLN function.

  
  
• b.
  

  Essential prior to reoperation

Most cases of PHPT are diagnosed following an incidental finding of elevated serum calcium.

Calcium, total vitamin D, and PTH should be measured together.

Measure 24-hour urine calcium excretion in order to distinguish PHPT from familial hypocalciuric hypercalcemia.

Other laboratory abnormalities in PHPT include hypophosphatemia and mild hyperchloremic acidosis secondary to renal involvement.

Use creatinine and blood urea nitrogen (BUN) to rule out renal insufficiency.

Patients who have had gastric bypass surgery should have calcium challenge to assure absorptive ability.

Preoperative imaging/localization results in

• a.
  

  Increased operative success

  
  
• b.
  

  Decreased surgical risk/extent of dissection

  
  
• c.
  

  Decreased operative time

Imaging is particularly important prior to reoperation.

Imaging guides the operative approach.

Imaging has no role in the diagnosis of PHPT.

Imaging options:

• a.
  

  Ultrasound

  
  
  
  
  • 1)
    

    Parathyroid adenomas have a homogeneous hypoechoic appearance on ultrasound.

    
    
  • 2)
    

    Ultrasound has emerged as the preferred initial preoperative localization method for many surgeons and endocrinologists.

    
    
  • 3)
    

    Ultrasound can screen for concomitant thyroid lesions that require surgical intervention, though the sensitivity of ultrasound is diminished in those with concurrent thyroid disease.

    
    
  • 4)
    

    As in other applications, the major limitation of sonography is that accuracy is operator-dependent.

  
  
  
  
• b.
  

  Technetium-99m sestamibi scintigraphy ( Fig. 84.3 )

  
  
  
  
  • 1)
    

    Sestamibi scintigraphy has been the traditional standard for preoperative localization.

    
    
  • 2)
    

    Planar images are captured after the injection of the radiotracer technetium-99m-methoxyisobutylisonitrile (MIBI), which is taken up preferentially by the mitochondria of the cells of the hyperfunctioning parathyroid gland(s).

  
  

  
  

  
  

  

  
  

  
  

  Sestamibi scintigraphy.

  
  

  This scan shows increased activity on the right. In the presence of hypercalcemia, this finding suggests a parathyroid adenoma.

  
  

Patients with familial hyperparathyroidism, MEN type 1, and MEN type 2A only need ultrasound to screen for coexistent thyroid disease because they will undergo four-gland exploration.

Symptomatic PHPT, including parathyroid crisis

Familial PHPT

Suspicion for parathyroid cancer

Presence of thyroid disease that can be surgically treated at the same time as PHPT

Asymptomatic PHPT patients in whom at least one of the following is true :

• a.
  

  Age less than 50 years

  
  
• b.
  

  Serum calcium greater than 1 mg/dL above the upper limit of normal

  
  
• c.
  

  Bone mineral density T score less than –2.5

  
  
• d.
  

  Vertebral fracture

  
  
• e.
  

  Creatinine clearance less than 60 mL/minute or reduced more than 30% for age

  
  
• f.
  

  Twenty-four-hour urine calcium greater than 400 mg/dL

  
  
• g.
  

  Nephrolithiasis or nephrocalcinosis on imaging

Contralateral RLN injury

Symptomatic cervical disc disease

Other comorbidities that preclude surgery

Discontinue antiplatelet and anticoagulation medications

An important factor for surgically curing PHPT and minimizing morbidity is correctly determining the extent of the surgery that should be performed

• a.
  

  Minimally invasive parathyroidectomy (MIP), which generally consists of successful preoperative localization, cervical block anesthesia, a smaller incision, and intraoperative PTH monitoring, results in complication and cure rates equal to or better than traditional bilateral neck exploration (BNE) and may reduce costs.

  
  
  
  
  • 1)
    

    The success rate of parathyroidectomy for PHPT, via either MIP or traditional BNE, approaches 95% to 97% in experienced, high volume surgical centers.

  
  
  
  
• b.
  

  Video-assisted (endoscopic) parathyroidectomy is a minimally invasive technique that has excellent safety and outcomes.

  
  
  
  
  • 1)
    

    It is performed under local or general anesthesia with intraoperative PTH monitoring in patients with positive preoperative localization of a single adenoma.

    
    
  • 2)
    

    Video augmentation with 30-degree endoscopes provides optimal illumination and magnification.

    
    
  • 3)
    

    Potential benefits include improved cosmesis and reduced postoperative cervical discomfort.

  
  
  
  
• c.
  

  Bilateral cervical exploration remains the first-line option for certain subsets of the PHPT population:

  
  
  
  
  • 1)
    

    Patients with nonlocalizing, equivocal, or contradicting preoperative imaging

    
    
  • 2)
    

    Suspected multiglandular disease; most hereditary forms of PHPT cause multiglandular disease:

    
    
    
    
    • a)
      

      MEN type 1

      
      
      
      
      • i)
        

        Subtotal parathyroidectomy, which consists of the removal of three and a half glands, or total parathyroidectomy with autotransplantation

        
        
      • ii)
        

        Thymectomy is also performed, since the thymus is the most common site of supernumerary parathyroid glands, which are common in MEN type 1.

        
        
      • iii)
        

        It is important to diagnose MEN preoperatively because undiagnosed patients may undergo MIP instead of BNE, likely resulting in operative failure.

      
      
      
      
    • b)
      

      MEN type 2A

      
      
      
      
      • i)
        

        Usually BNE with resection of enlarged glands, but some prefer subtotal or total parathyroidectomy

      
      
      
      
    • c)
      

      Familial isolated hyperparathyroidism

      
      
      
      
      • i)
        

        Subtotal or total parathyroidectomy and thymectomy

      
      
      
      
    • d)
      

      Familial neonatal hyperparathyroidism

      
      
      
      
      • i)
        

        Treat urgently with total parathyroidectomy and thymectomy.

      
      

    
    
    
    
  • 3)
    

    Failure of intraoperative PTH to normalize after unilateral exploration

    
    
  • 4)
    

    Concurrent indication for thyroidectomy

  
  
  
  
• d.
  

  Despite the high success rate of parathyroidectomy, the surgeon’s experience and expertise are invaluable in parathyroid surgery.

  
  
  
  
  • 1)
    

    When a minimally invasive procedure is chosen as the initial approach, the surgeon must know when and how to convert the procedure to a BNE.

    
    
    
    
    • a)
      

      The most common reasons for conversion are incorrect preoperative localization, failure of normalization of intraoperative PTH, and intraoperative evidence of multiglandular disease.