Secondary Hypertension and Bariatric Surgery

Secondary Hypertension

Causes of Secondary Hypertension

• Renal: Stenosis, PCKD, Obstruction
• Endocrine: Cushing's syndrome, Adrenogenital syndrome, Pheochromocytoma, Acromegaly
• Aorta Coarctation
• Other: Thyroid disorders, Hypercalcemia

Red Flags in Secondary Hypertension

• Hypokalemia
• Early age of onset
• Patient over 50 years old
• High severity
• Refractory to therapy
• Increased paroxysmal blood pressure
• Absence of obesity

Pheochromocytoma

Diagnosis

• Plasma metanephrine level
• Urine free catecholamine
• Ultrasound/CT
• MIBG In-111

Cushing's Syndrome

Diagnosis

• 24-hour urine cortisol
• 1 mg dexamethasone suppression test (screening)
• 8 mg dexamethasone suppression test
• Cortisol circadian rhythm
• Laboratory tests: Increased hematocrit/hemoglobin, decreased eosinophils
• Sinus/petrous imaging

Multiple Endocrine Neoplasia (MEN) Syndromes

MEN-1 (Wermer Syndrome)

• Mutation on chromosome 11
• Includes: Hyperparathyroidism, Pancreatic tumors, Pituitary adenomas

MEN 2A (Sipples Syndrome)

• Autosomal dominant
• Includes: Pheochromocytoma, Medullary thyroid cancer, Hyperparathyroidism, Hirschsprung disease
• Treatment: Prophylactic thyroidectomy (screen for pheochromocytoma before surgery)

MEN 2B

• Includes: Pheochromocytoma, Medullary thyroid cancer, Marfanoid habitus
• Treatment: Prophylactic thyroidectomy

Bariatric Surgery

Types of Bariatric Surgery

Restrictive

• Gastric band
• Sleeve gastrectomy
• Greater curvature plication

Malabsorptive

• Biliopancreatic diversion
• Biliopancreatic diversion with duodenal switch

Combined

• Roux-en-Y gastric bypass

Restrictive Procedures

Gastric Band

Advantages

• Anatomical continuity
• Lowest risk of postoperative complications

Disadvantages

• Foreign object
• Late complications can occur
• Difficulty with feeding
• Least amount of weight loss
• Vomiting
• Food intolerance

Sleeve Gastrectomy

Advantages

• Gastrointestinal continuity
• Better eating than gastric band
• Increased incretin levels

Disadvantages

• Risk of immediate complications
• Gastrointestinal reflux
• Long-term effects uncertain

Greater Curvature Plication

Advantages

• Gastrointestinal continuity
• Cost-effective

Disadvantages

• Gastrointestinal reflux
• Long-term effects unknown
• Still under development

Malabsorptive Procedures

Biliopancreatic Diversion with Duodenal Switch

Advantages

• Significant weight loss
• Good long-term results
• Low comorbidity rates

Disadvantages

• Highest risk of immediate postoperative complications
• Fat-soluble vitamin supplementation required

Who Benefits from Malabsorptive Procedures?

• Prader-Willi syndrome
• BMI > 50
• Type 2 diabetes mellitus if sleeve gastrectomy fails

Combined Procedures

Gastric Bypass

Advantages

• Greater weight loss than restrictive procedures
• Better eating
• No cheating (no fat/sweet foods)
• Increased post-meal incretin levels

Disadvantages

• Increased postoperative risk
• Vitamin B12 and C supplementation required

Diabetes Mellitus

Diagnosis