Handbook of Surgical Consent
Annotate
Cite
Adrenalectomy
Description
The adrenal glands are paired retroperitoneal organs situated superior to the kidneys. They consist of two functional units, the adrenal cortex (secreting glucocorticoids (cortisol), mineralocorticoids (aldosterone), and sex hormones) and the adrenal medulla (secreting catecholamines, e.g. noradrenaline, adrenaline, and dopamine).
Adrenal masses can be classified into functioning and non-functioning tumours. In over 5% of routine cross-sectional imaging, an incidental adrenal mass (incidentaloma) may be found. Benign adrenal adenomas represent the commonest adrenal tumours (>60%). Adrenocortical carcinoma is rare and carries a dismal prognosis. Metastases to the adrenal gland from melanoma, lung, breast, and renal carcinoma can be found in up to 73% of cases. Indications for surgery are listed as follows.
Non-functioning tumours
Incidentaloma >4cm or increasing in size
Symptomatic adrenal cyst/angiolipoma
Solitary adrenal metastasis
Adrenocortical carcinoma
Functioning tumours
Phaeochromocytoma
Conn's syndrome (adenoma)
Cushing's syndrome
Unsuccessful hypophysectomy for Cushing's disease
Bilateral adrenal hyperplasia
Feminizing/virilizing tumours
Adrenocortical carcinoma
Preoperative work-up for these patients include:
Metaiodobenzylguanidine (MIBG) scintigraphy and [18F]2-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) may be used selectively
Assessment of hormonal function
Lateralization of abnormal function—angiography and adrenal vein sampling may be used to accurately determine laterality of disease in Conn's syndrome
Preoperative control of hormonal dysfunction is mandatory (e.g. A-adrenergic blockade in phaeochromocytoma, control of blood pressure and hypokalaemia in Conn's syndrome)
Cross-sectional imaging
CT and MRI are the gold standard and allow for assessment of size and further characterization of the mass. Size is the strongest predictor of malignancy (prevalence of adrenocortical cancer: 2% with lesions <4cm, 6% with lesions 4.1–6cm, 25% with lesions >6cm)1
Operative procedure
Laparoscopic adrenalectomy represents the standard of care for resection of benign functioning or non-functioning adrenal tumours. More recently, the retroperitoneoscopic adrenalectomy is gaining wider acceptance. There is currently little evidence to support the oncological safety of laparoscopic techniques in management of adrenocortical cancer and thus an open adrenalectomy is recommended.
Approach to the adrenal glands requires clear appreciation of anatomy and the relationship of the glands to other retroperitoneal organs. The laparoscopic transperitoneal adrenalectomy is carried out with the patient in the lateral decubitus position. A four-port technique is commonly used for approach to the right adrenal gland with the most medial port being used for insertion of a liver retractor.
The right adrenal gland is exposed by rotating the liver medially by dividing the triangular ligament. On the left, a three-port technique is used. Exposure of the left adrenal gland requires division of the lienophrenic ligament and medial rotation of the spleen. It is of paramount importance to ensure minimal traction on the liver or the spleen to prevent problematic haemorrhage from capsular tears.
The right adrenal vein has a short drainage course into the inferior vena cava. In up to 20% of cases, the adrenal vein may drain into an accessory right hepatic vein. Incision of the peritoneal layer over the right adrenal gland is followed by dissection along the course of the retrohepatic inferior vena cava to its confluence with the adrenal vein. The adrenal vein is skeletonized and ligated. Blood supply to the adrenal gland is segmental and individual feeding arteries need to be accurately controlled.
Exposure of the left adrenal gland follows the same principles. Care is required to preserve the left renal vein, particularly if an accessory adrenal vein drains into it. Dissection of the adrenal gland is carried out within the peri-adrenal fat with careful attention to haemostasis and minimal manipulation of the gland. On the left, the tail of the pancreas is in close proximity to the gland and needs to be avoided. Where tumour infiltration into the surrounding tissues is encountered, conversion from a laparoscopic to open technique may be required with view to en-bloc resection of involved organs.
Close postoperative monitoring is specifically required following resection of phaeochromocytomas as large fluctuations in blood pressure are anticipated. Peri- and postoperative glucocorticoid and mineralocorticoid supplementation is initiated as required.
Additional procedures that may become necessary
Abdominal drain insertion
Chest drain insertion
Nephrectomy
Benefits
Diagnostic: to provide a histological diagnosis for underlying adrenal tumour development
Therapeutic: treatment of symptomatic adrenal pathology, remove tumour from adrenal gland whether primary or secondary, restore hormonal equilibrium after surgery with medication as required
Alternative procedures/conservative measures
Medical: conservative watchful waiting with serial radiological follow-up, analgesia, hormonal and steroid therapy as necessary
Surgical: open, laparoscopic, RFA (currently in research phase)
Serious/frequently occurring risks
Intra-/postoperative haemorrhage from adrenal vein stump, accessory adrenal veins or accessory hepatic veins
Inadvertent injury to adjacent organ; liver capsule or parenchymal injury, splenic injury requiring splenectomy, bowel injury (especially splenic flexure during left adrenalectomy), damage to the tail of the pancreas, injury to bowel during laparoscopic port insertion
Pleural effusion/lower lobe pneumonia
DVT/pulmonary embolism
Pneumothorax
Postoperative adrenal insufficiency (addisonian crisis)
Death (2009 national crude mortality rate 0.6%)2
Blood transfusion necessary
• Group and save
Type of anaesthesia/sedation
• General anaesthesia with appropriate invasive and non-invasive monitoring (central venous pressure (CVP)/arterial line)
Follow-up/need for further procedure
Routine postoperative surgical follow-up to ensure satisfactory healing
Endocrinological follow-up for clinical and biochemical confirmation of cure (e.g. reduction in antihypertensive requirements and potassium supplementation in Conn's syndrome)
Short Synacthen test—indicated following unilateral adrenalectomy in Cushing's syndrome as predictor of return of contralateral adrenal function
References
Parathyroidectomy
Description
Hyperparathyroidism (HPT) is a condition of abnormal excessive parathyroid hormone (PTH) production and a resultant calcium and phosphate disturbance. It is broadly categorized into: primary, secondary (e.g. chronic kidney disease), and tertiary. Primary HPT is the commonest metabolic condition requiring surgical intervention. Commonly, it is as a result of a single hyperfunctioning adenoma (80%) and less frequently due to multiple gland hyperplasia (∼15%). Parathyroid carcinoma is a rare cause (<1%).
Indications for surgery
Symptomatic primary HPT ± evidence of end-organ damage (e.g. nephrolithiasis, osteopaenia/porosis)
Asymptomatic primary HPT (meeting National Institutes of Health (NIH) criteria: age <50 years, osteitis fibrosa cystica, nephrocalcinosis, serum [Ca2+] >1mg/dl above normal range, urinary calcium excretion >400mg/day, reduced bone mineral density >2SD matched controls, surveillance not possible or undesirable)1
Hypercalcaemic crisis (Ca >3.5mmol/L)
Parathyroid carcinoma
Renal HPT (current practice follows evidence-based guidelines, e.g. Kidney Disease Outcomes Quality Initiative (KDOQI))2
Preoperative work-up
Unequivocal biochemical diagnosis is mandatory (exclude other causes, e.g. familial hypocalciuric hypercalcaemia)3
Assessment of severity of HPT and evidence of end-organ damage
Imaging: extensive attempts should be made to localize the abnormal glands with concordance between two imaging modalities.4 The commonest imaging techniques uses are ultrasound and sestamibi-scintigraphy. Other techniques are selectively used (e.g. CT, MRI, PET, selective venous sampling). Localization is seldom indicated in primary surgery for renal HPT. Localization studies do not impact cure rates but influence the choice for targeted approach to parathyroidectomy
Preoperative vocal cord check (mandatory)5
Operative procedure
The surgical management of HPT requires a thorough understanding of the anatomy and embryology of the parathyroid glands. The surgical approach (bilateral cervical exploration versus focused approach) may be dictated by the localization studies and the underlying pathology. Accurate localization allows for the use of focused and minimally invasive techniques.
The open/bilateral cervical exploration remains the gold standard approach. An open parathyroidectomy is performed through a 4–5cm midline cervical incision with dissection through layers as for a thyroidectomy. The superior glands are constant in position and lie in a more posterior plane to the thyroid gland and intimately related to the recurrent laryngeal nerve, which lies in a medial plane at the level of the larynx. The position of the inferior glands is more variable, and they are often found within the thyrothymic ligament. However, they can occur anywhere along the line of decent of the gland from foramen caecum to the mediastinum.
The aim of parathyroidectomy is to remove the pathological gland(s). In multiple gland disease two, three, three-and-half or all four glands may be excised. In rare occurrence of ectopic parathyroid glands, exploration of paraoesophageal space, the carotid sheath and the anterior mediastinum (via a sternotomy) may be required. More recently, rapid intraoperative PTH analysis has been used to aid intraoperative validation of cure.
Additional procedures that may become necessary
Drain insertion
Multiple parathyroidectomy
Rarely thyroid lobectomy for an intra-thyroidal gland
Benefits
Diagnostic: provide histological diagnosis for underlying parathyroid abnormality
Therapeutic: prevention of complications of symptomatic HPT and prevent associated end-organ damage, treatment of parathyroid carcinoma
Alternative procedures/conservative measures
Medical: conservative watchful waiting with serial radiological follow-up, analgesia, biochemical and electrolyte correction with calcium binding agents as necessary, and calcimimetics e.g. Cinacalcet
Serious/frequently occurring risks
Early postoperative haemorrhage requiring reoperation (0.6–0.8%)5
Injury to the recurrent laryngeal nerve (primary surgery = 0.8%, redo surgery 2%)4
Failure to cure (overall ∼5%5—rates are marginally higher in un-localized disease and multiple endocrine neoplasia (MEN) 1)
Postoperative hypocalcaemia
Complication rates are higher in reoperative cases
Blood transfusion necessary
• None/group and save
Type of anaesthesia/sedation
Local/regional anaesthesia may be feasible in minimally invasive/focused approach
General anaesthesia required for cervical exploration
Follow-up/need for further procedure
Interval follow-up to ensure normalization of calcium and PTH
Postoperative vocal cord check (recommended)3
References
www.baets.org.uk/Pages/BAETS%20Guidelines.pdf (accessed 25 May
2011).Thyroidectomy
Description
Thyroid surgery involves a variety of operations including:
Total thyroidectomy
Hemithyroidectomy (excision of one thyroid lobe and the isthmus)
Isthmusectomy (resection of the isthmus only)
Subtotal thyroidectomy (seldom practised due to high recurrence/reoperation rate)
Indications for surgery
Goitre/nodule with local compressive symptoms
Graves’ thyrotoxicosis refractory/unsuitable to medical treatment
Thyroid cancer
Diagnostic procedure for a cytologically indeterminate lesion
Improving cosmesis in a large goitre
Preoperative work-up
Assessment of thyroid function—thyroidectomy is contraindicated in uncontrolled thyrotoxicosis
Cytological assessment of a solitary nodule (fine needle aspiration cytology (FNAC))
Imaging—assessment of functionality with I123 scintigraphy, ultrasound and cross-sectional imaging with CT (for assessment of retrosternal/mediastinal extension and airway compromise)
Preoperative vocal cord check (mandatory)1
Operative procedure
The patient is prepared supine with next extension (Fig. 5.1). A transverse (Kocker's) skin crease incision is made 1–2cm below the cricoid cartilage (Fig. 5.2). Platysmal flaps are raised with preservation of the anterior jugular veins. The strap muscles are separated along their midline raphe and the plane between the thyroid gland and the strap muscles created. Ligation of the middle thyroid vein confers further mobility to the gland.
Patient positioning for thyroidectomy.
Gross anatomy and vascular supply to the thyroid gland.
The upper pole of the thyroid gland is isolated by ligation and division of the superior thyroidal vessels. Care is taken to preserve the external branch of the superior laryngeal nerve in the avascular space between the upper pole and the cricothyroid muscle. The superior parathyroid gland and the recurrent laryngeal nerve (RLN) are identified and preserved. The branches of the inferior thyroidal artery and veins are ligated in the per-capsular plane of the thyroid. Inferiorly, the thyroid gland is dissected from the thyrothymic ligament, while identifying and preserving the inferior parathyroid glands.
Dissection at Berry's ligament requires special care due to the close proximity of RLN entering the larynx. Meticulous attention to haemostasis is mandatory. Occult venous bleeding can be identified by placing the patient head down and increasing venous pressure with the Valsalva manoeuvre. Closure is carried out with approximation of the strap muscles, platysma, and the skin.
In a hemithyroidectomy, the dissection is completed at the level of the isthmus with excision of the pyramidal lobe (present in ∼80%). A total thyroidectomy involves the dissection of the contralateral lobe following the principles already outlined. In the presence of a retrosternal goitre, a sternotomy is occasionally required (<10% of cases).
Additional procedures that may become necessary
Drain insertion
Parathyroid autotransplantation
Benefits
Diagnostic: obtain a histopathological diagnosis of underlying thyroid pathology
Therapeutic: treatment of symptomatic thyroid pathology, remove tumour of thyroid gland whether primary or secondary, restore hormonal equilibrium with surgery and postoperative thyroid hormone replacement as required
Alternative procedures/conservative measures
Selective cervical lymphadenectomy (levels III–VI) is recommended for locoregional control in clinically apparent lymph node metastases. In medullary thyroid cancer bilateral cervical lymphadenectomy is recommended
The role of prophylactic central compartment (level VI) lymphadenectomy in management of papillary thyroid cancer is contentious and currently recommended in patients with clinically uninvolved central compartment nodes and more advanced tumours (stages T3 and T4)3
Radio-iodine thyroid ablation
Chemical (drug induced) thyroid suppression
Serious/frequently occurring risks
Early postoperative haemorrhage requiring reintervention (maximal risk in the first 6–12h, overall rate 0.9%)2
Voice change (overall 4.9%)2
Injury to the RLN (overall 2.5%)2
Hypocalcaemia (may be temporary or permanent; overall rate 11%, long-term 7%)2
Mortality (0.24%)2
Risk of RLN palsy and postoperative hypocalcaemia is greater following lateral cervical lymphadenectomy
Complication rates are higher in reoperative cases. Individual surgeon complication rates vary and may depend on caseload
Blood transfusion necessary
• None/group and save
Type of anaesthesia/sedation
• General anaesthesia
Follow-up/need for further procedure
Check for calcium and PTH homeostasis following a total thyroidectomy
Thyroid function test (thyroxine replacement is titrated against clinical and biochemical response)
Post-operative vocal cord check (recommended)1
References
www.baets.org.uk/Pages/Vocal_cord_check_consenus_document_2010_final.pdf
(accessed 17 May 2011).
