Total or near-total thyroidectomy versus subtotal thyroidectomy for multinodular non-toxic goitre in adults

Review question

What are the effects of total or near-total thyroidectomy compared with subtotal thyroidectomy for multinodular non-toxic goitre in adults?

Background

Multinodular goitre refers to a generalised enlarged thyroid gland with recognisable nodules within it. The thyroid gland consists of two connected lobes. People affected by goitre often present with a non-symmetrical enlargement of the thyroid gland with a visible swelling in the anterior aspect of the neck. One or more nodules can be recognised. The most frequent cause of multinodular goitre is iodine deficiency. Non-toxic goitre means that the nodules do not secret thyroid hormones in an uncontrolled way. Total thyroidectomy is an operation that involves the surgical removal of the whole thyroid gland. Near-total thyroidectomy is an operation that involves the surgical removal of both thyroid lobes except for a small amount of thyroid tissue (on one or both sides less than 1.0 mL). Subtotal thyroidectomy leaves 3 g to 5 g on the less affected side of the thyroid gland.

After thyroidectomy one of the most important complications is recurrent nerve palsy because this nerve might be traumatised during the surgery. A wide spectrum of complications to the voice, swallowing mechanisms, or both, can occur. A temporary or permanent voice change can result. If the goitre reappears (goitre recurrence) some time after thyroidectomy, another surgical intervention might be necessary. This surgery is more complicated than the initial surgery because of scar tissue making it difficult to identify nerves and other important tissues. There is also the possibility that subtotal thyroidectomy, which is thought to be somewhat safer than total thyroidectomy, may leave an undetected thyroid cancer in place.

Study characteristics

We included four randomised controlled trials with a total of 1305 participants. A total of 543 participants were randomised to total or near-total thyroidectomy and 762 participants to subtotal thyroidectomy. Two trials had a duration of follow-up between 12 and 39 months and two trials a follow-up of 5 and 10 years, respectively. Most participants were women and the average age was around 50 years.

Key results

In the short-term period after surgery no deaths were reported for both total thyroidectomy and subtotal thyroidectomy groups, however longer-term data on all-cause mortality were not reported. Goitre recurrence was lower for total thyroidectomy compared to subtotal thyroidectomy: the risk for goitre recurrence was 84 per 1000 trial participants for subtotal thyroidectomy and 5 per 1000 participants (with a possible range of 1 to 19) for total thyroidectomy. There was no clear benefit or harm of either surgical technique for re-operations because of goitre recurrence, side effects like permanent recurrent laryngeal nerve palsy or development of thyroid cancer. No data on health-related quality of life or socioeconomic effects were reported in the included trials.

Quality of the evidence

The overall quality was low to moderate, mainly because of the small number of studies and participants as well as low rates of events which makes distinction between harms and benefits of the two surgical techniques difficult.

Currentness of evidence

This evidence is up to date as of June 2015.

Authors' conclusions: 

The body of evidence on TT compared with ST is limited. Goiter recurrence is reduced following TT. The effects on other key outcomes such as re-interventions due to goitre recurrence, adverse events and thyroid cancer incidence are uncertain. New long-term RCTs with additional data such as surgeons level of experience, treatment volume of surgical centres and details on techniques used are needed.

Read the full abstract...
Background: 

Total thyroidectomy (TT) and subtotal thyroidectomy (ST) are worldwide treatment options for multinodular non-toxic goitre in adults. Near TT, defined as a postoperative thyroid remnant less than 1 mL, is supposed to be a similarly effective but safer option than TT. ST has been shown to be marginally safer than TT, but it may leave an undetected thyroid cancer in place.

Objectives: 

The objective was to assess the effects of total or near-total thyroidectomy compared to subtotal thyroidectomy for multinodular non-toxic goitre.

Search strategy: 

We searched the Cochrane Library, MEDLINE, PubMed, EMBASE, as well as the ICTRP Search Portal and ClinicalTrials.gov. The date of the last search was 18 June 2015 for all databases. No language restrictions were applied.

Selection criteria: 

Two review authors independently scanned the abstract, title or both sections of every record retrieved to identify randomised controlled trials (RCTs) on thyroidectomy for multinodular non-toxic goitre for further assessment.

Data collection and analysis: 

Two review authors independently extracted data, assessed studies for risk of bias and evaluated overall study quality utilising the GRADE instrument. We calculated the odds ratio (OR) and corresponding 95% confidence interval (CI) for dichotomous outcomes. A random-effects model was used for pooling data.

Main results: 

We examined 1430 records, scrutinized 14 full-text publications and included four RCTs. Altogether 1305 participants entered the four trials, 543 participants were randomised to TT and 762 participants to ST. A total of 98% and 97% of participants finished the trials in the TT and ST groups, respectively. Two trials had a duration of follow-up between 12 and 39 months and two trials a follow-up of 5 and 10 years, respectively. Risk of bias across studies was mainly unknown for selection, performance and detection bias. Attrition bias was generally low and reporting bias high for some outcomes. In the short-term postoperative period no deaths were reported for both TT and ST groups. However, longer-term data on all-cause mortality were not reported (1284 participants; 4 trials; moderate quality evidence). Goiter recurrence was lower in the TT group compared to ST. Goiters recurred in 0.2% (1/425) of the TT group compared to 8.4% (53/632) of the ST group (OR 0.05 (95% CI 0.01 to 0.21); P < 0.0001; 1057 participants; 3 trials; moderate quality evidence). Re-intervention due to goitre recurrence was lower in the TT group compared to ST. Re-intervention was necessary in 0.5% (1/191) of TT patients compared to 0.8% (3/379)of ST patients (OR 0.66 (95% CI 0.07 to 6.38); P = 0.72; 570 participants; 1 trial; low quality evidence). The incidence of permanent recurrent laryngeal nerve palsy was lower for ST compared with TT. Permanent recurrent laryngeal nerve palsy occurred in 0.8% (6/741) of ST patients compared to 0.7% (4/543) of TT patients (OR 1.28, (95% CI 0.38 to 4.36); P = 0.69; 1275 participants; 4 trials; low quality evidence). The incidence of permanent hypoparathyroidism was lower for ST compared with TT. Permanent hypoparathyroidism occurred in 0.1% (1/741) of ST patients compared to 0.6% (3/543) of TT patients (OR 3.09 (95% CI 0.45 to 21.36); P = 0.25; 1275 participants: 4 trials; low quality evidence). The incidence of thyroid cancer was lower for ST compared with TT. Thyroid cancer occurred in 6.1% (41/669) of ST patients compared to 7.3% (34/465)of TT patients (OR 1.32 (95% CI 0.81 to 2.15); P = 0.27; 1134 participants; 3 trials; low quality evidence). No data on health-related quality of life or socioeconomic effects were reported in the included studies.

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