Thoracoscopic excision of mediastinal parathyroid tumours (interventional procedures consultation)

NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE

Interventional Procedure Consultation Document

Thoracoscopic excision of mediastinal parathyroid tumours

Parathyroid tumours usually develop in the neck, but rarely they are found in the chest, and these mediastinal parathyroid tumours will require major surgery to remove them. Parathyroid tumours may release too much parathyroid hormone, which raises the level of calcium in the bloodstream. Thoracoscopic excision uses 'keyhole surgery' to remove tumours, guided by a flexible camera inserted into the chest.

The National Institute for Health and Clinical Excellence is examining thoracoscopic excision of mediastinal parathyroid tumours and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. The Institute's Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about thoracoscopic excision of mediastinal parathyroid tumours .

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

comments on the preliminary recommendations
the identification of factual inaccuracies
additional relevant evidence.

Note that this document is not the Institute's formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that the Institute will follow after the consultation period ends is as follows.

The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
The Advisory Committee will then prepare draft guidance which will be the basis for the Institute's guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

For further details, see the Interventional Procedures Programme manual, which is available from the Institute's website (www.nice.org.uk/ipprogrammemanual).

Closing date for comments: 25 September 2007
Target date for publication of guidance: December 2007

Note that this document is not the Institute's guidance on this procedure. The recommendations are provisional and may change after consultation.

1	Provisional recommendations

1.1	Limited evidence supports the efficacy of thoracoscopic excision of mediastinal parathyroid tumours. The evidence is very limited in quantity, and in view of potential complications of the procedure it should not be used without special arrangements for clinical governance, consent, audit and research.
1.2	Clinicians wishing to undertake thoracoscopic excision of mediastinal parathyroid tumours should take the following actions. Inform the clinical governance leads in their Trusts. Ensure that patients understand the potential complications of the procedure and provide them with clear written information. Use of the Institute?s information for patients (?Understanding NICE guidance?) is recommended (available from www.nice.org.uk/IPG XXX publicinfo). *[[details to be completed at publication]]* Audit and review clinical outcomes of all patients having thoracoscopic excision of mediastinal parathyroid tumours (see section 3.1). It is recommended that clinicians undertaking this procedure should collaborate in the collection and review of data.
1.3	Patient selection for thoracoscopic excision of mediastinal parathyroid tumours should be carried out in specialist units and in the context of a multidisciplinary team that includes a thoracic surgeon experienced in thoracoscopic techniques. Preoperative imaging should always be undertaken to confirm the location of the mediastinal tumour.

The procedure

2.1

Indications

2.1.1

There are usually four parathyroid glands situated in the neck, but in about 10% of people one or more of the glands are located in the mediastinum. Parathyroid tumours (most commonly benign adenomas) can develop in any of these glands.

2.1.2

Parathyroid adenomas are a cause of primary hyperparathyroidism, characterised by the excessive production of parathyroid hormone, which results in high blood calcium levels. Symptoms include tiredness, depression, confusion, constipation, polydipsia, polyuria, development of kidney stones, bone pain and fractures.

2.1.3

The management of hyperparathyroidism may include dietary modification and the use of parathyroid hormone inhibitors. Surgical treatment may be required for some patients.

2.1.4

Parathyroid tumours situated in the neck can be removed surgically, usually through a cervical incision; however tumours located in the mediastinum require a thoracotomy. Mediastinal parathyroid adenomas may also be treated by angiographic ablation or by computed tomography (CT)-guided ethanol ablation. Thoracoscopic excision of mediastinal parathyroid adenoma aims to reduce the morbidity and potential complications that may be associated with open procedures.

2.2

Outline of the procedure

2.2.1

The location of the tumour is determined by imaging (for example CT, ultrasound or scintigraphy). Under general anaesthesia, a number of ports are placed in the intercostal spaces for the thoracoscope and instruments. One lung may be deflated to aid visualisation. The ectopic parathyroid gland is identified and dissected while keeping its capsule intact. The vascular pedicle is clipped and the gland is removed through one of the ports. A chest drain may be inserted. The ports are closed and the lung is inflated if necessary.

2.3

Efficacy

2.3.1

In three case series and in five case reports (7/7, 4/4, 4/4, 3/3, 2/2, 1/1, 1/1, 1/1) successful excision without conversion to open surgery was achieved in 100% of patients.

2.3.2

In the first case series of four patients, a case report of two, and all three case reports of one patient, serum calcium levels were normalised in all patients immediately following thoracoscopic excision of mediastinal parathyroid adenoma, with mean levels of 8.6 mg/100 ml, 8.6 and 10.3 mg/100 ml, 1.9 mmol/l, 9.2 mg/100 ml and 5.7 mg/100 ml, respectively, shortly after surgery. In the first single case report a normalised serum calcium level (2.5 mmol/l) was maintained at 3-year follow-up. For more details, refer to the sources of evidence (see appendix).

2.3.3

The Specialist Advisers listed key efficacy outcomes as improvement in serum calcium and parathyroid hormone levels, and in rates of histological confirmation of parathyroid adenoma and conversion to open surgery.

2.4

Safety

2.4.1

One case report described hypocalcaemia (severity not stated) immediately following the procedure, which had normalised at 3 day follow-up.

2.4.2

One case report described a small apical pneumothorax following the procedure, which had resolved at 2-week follow-up.

2.4.3

A case series of three patients recorded transient hoarseness in one patient, which was presumed to have resulted from damage to the left recurrent laryngeal nerve.

2.4.4

The Specialist Advisers stated that anecdotal and theoretical complications include bleeding, infection, chest wall pain, arrhythmias and catastrophic damage to the mediastinal contents, including the great veins and major arteries.

2.5

Other comments

2.5.1

It was noted that some tumours may be malignant and this may influence the technique used.

3	*Further information*
3.1	This guidance requires that clinicians undertaking the procedure make special arrangements for audit. The Institute has identified relevant audit criteria and is developing an audit tool (which is for use at local discretion), which will be available when the guidance is published.
3.2	The Institute has produced technology appraisals guidance on cinacalcet for the treatment of secondary hyperparathyroidism in patients with end-stage renal disease on maintenance dialysis therapy (www.nice.org.uk/TA117).

Bruce Campbell
Chairman, Interventional Procedures Advisory Committee
August 2007

Appendix:

Sources of evidence

The following document, which summarises the evidence, was considered by the Interventional Procedures Advisory Committee when making its provisional recommendations.

' Interventional procedure overview of thoracoscopic excision of mediastinal parathyroid tumours', June 2007.

Available from: www.nice.org.uk/ip406overview.

This page was last updated: 30 March 2010