Multivariate Analysis of Risk Factors for Postoperative Complications in Benign Goiter Surgery: Prospective Multicenter Study in Germany

Abstract

Risk factors for postoperative complications of benign goiter surgery have not been investigated systematically. To this end, a prospective multicenter study (January 1 through December 31, 1998) was conducted involving 7266 patients with surgery for benign goiter from 45 East German hospitals. High-volume providers (>150 operations per year) performed 69% (5042/7266), intermediate-volume providers 27% (50-150), and low-volume providers 4% (258/7266) of operations. Among the hospital groups, the pattern of thyroid disease did not vary significantly, but there was a trend that small-volume providers tended to perform more operations for uninodular goiter and high-volume providers treated more patients with Graves' disease and recurrent goiter. Extent of resection (p < 0.0001) and remnant size (multinodular goiter and recurrent goiter, p < 0.001), differed significantly, with total thyroidectomy being performed more often in hospitals with more than 150 operations compared to hospitals with an operative volume of less than 150 procedures per year. Despite the larger extent of resection and smaller remnant size, rates of recurrent laryngeal nerve (RLN) palsy or hypoparathyroidism were not increased. When the logistic regression analyses were fitted to evaluate the impact of risk factors on transient and permanent RLN palsy and hypoparathyroidism, larger extent of resection [relative risk (RR) 1.5-2.1] and recurrent goiter (RR 1.8-3.4) consistently evolved as independent risk factors. With hypoparathyroidism, additional significant factors included patient gender (RR 2.1-2.4), hospital operative volume (RR 0.8-1.5), and Graves' disease (RR 2.8). Unlike parathyroid gland identification during hypoparathyroidism, RLN identification (RR 1.6) significantly (p = 0.01) reduced permanent RLN palsy rates. The multivariate analyses clearly confirmed the pivotal role of routine RLN identification, independent of the extent of the thyroid resection. These findings might help hospitals with lower operative volumes to identify patients at increased risk whom they might consider for specialist care.

Permanent hypocalcemia in patients operated for thyroid carcinoma

“…In our study, permanent hypocalcemia rates were higher in patients with reoperative thyroid surgery in comparison with group I, and this increase was signifi cant. Similarly, in many other studies, Table 1 The distribution of the patients according to the types of neck dissection the complication rates had not been shown to be increased with reoperative thyroid surgery [6,7,13]. Also, permanent hypocalcemia rates were found to be increased in patients with neck dissection [13,14].…”

“…In some other studies that compared total thyroidectomy with subtotal thyroid surgeries, permanent hypocalcemia rates were found to be higher in the former group and the conclusion was a correlation between the extent of surgery and the permanent hypocalcemia rates [6][7][8][9]. In a study by Thomusch et al more extensive surgery increased the relative risk of permanent hypocalcemia by 1.5-1.8 times [6].…”

“…In a study of 7,266 patients with benign thyroid disease by Thomusch et al, advanced age was found to be associated with permanent hypocalcemia [6]. In another study of 316 patients with differentiated thyroid carcinoma by Filho and Kowalski, age and gender were not associated with permanent hypocalcemia [13].…”

“…Besides, this rate was correlated with permanent hypocalcemia rates in reoperative thyroid surgery performed group. In another series of 5,846 patients, incidental parathyroidectomy was shown to be a risk factor for permanent hypocalcemia [6].…”

“…In a study by Thomusch et al more extensive surgery increased the relative risk of permanent hypocalcemia by 1.5-1.8 times [6]. However, in some other studies, it was concluded that more radical surgery did not result in higher rates of hypoparathyroidism [10,11].…”