SHORT COMMUNICATION

An Evaluation of the Intraoperative Staining Technique Using Methylene Blue for the Detection of

Hyperplastic Parathyroid Glands

Shinya KOBAYASHI, Makoto MIYAKAWA, Akira SUGENOYA, Osamu SENGA, Gengo KANEKO, Tamotsu YOKOZAWA, Yoshio KASUGA, Hiroyuki MASUDA, YU Tai CHANG and Futoshi IInA

ABSTRACT: Intraoperative staining with methylene blue was employed during parathyroid surgery on 50 glands from 13 patients, 5 with primary and 8 with secondary hyperparathyroidism. Forty-seven out of the 50 glands (94 per cent) were visualized by the staining and 2 out of the 13 patients were revealed to have supernumerary parathyroid glands. Since we started using this technique, there have been no cases of persistent hypercalcemia. The results of this study support the clinical usefulness of this staining procedure for detecting hyperplastic parathyroid glands in both primary and secondary hyperparathyroidism.

KEY WORDS: hyperparathyroidism, parathyroid gland, methylene blue staining

A _kMthough techniques for the preoperative localization of the parathyroid gland have improved recently, detection of the gland at surgery is not always easy, particularly in patients whose hyperparathyroidism is due to hyperplasia. Since Dudley I initially re- ported the application of methylene blue for intraoperatively detecting the parathyroid gland, there have been several reports sup- porting the usefulness of this method3 -~ In Japan, however, this technique is not yet widely accepted. In this investigation, the authors have therefore attempted to evaluate this technique in Japanese patients.

The Second Department of Surgery, Shinshu Univer- sity School of Medicine, Matsumoto, Japan

Reprint requests to: Shinya Kobayashi, MD, The Second Department of Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390, Japan

This paper was presented at the 19th Annual Meeting of the Japanese Society of Thyroid Surgery held in Beppu, Ohita on November 27th and 28th, 1986.

Fifty parathyroid glands which were re- moved from 13 patients with hyperparathy- roidism (HPT) due to hyperplasia were sub- jected to this study. These 13 patients con- sisted of 5 patients with primary (I ~ HPT) and 8 with secondary hyperparathyroidism (II ~ HPT). Eleven patients underwent surgery for the first time and 2 were re-operated on because of persistent hypercalcemia after their first operation.

All patients were administered 5 mg/kg body weight of methylene blue intravenously diluted in 200-500 ml of lactated Ringer's solution. The intravenous infusion was started one hour before surgery and ceased when surgery commenced, after which the surgeons evaluated the staining of the para- thyroid glands by the methylene blue.

As a control, 12 hyperplasti c patients (I ~ HPT 6 and II ~ HPT 6) who had been operated on before the staining technique was introduced were reviewed. A comparison of postoperative persistent hypercalcemia be-

JAPANESE JOURNAL OF SURGERY, VOL. 18, No. 6 pp. 729-731, 1988

pn. . Surg. 730 Kobayashi et al. N~o~vemb~r 1988

Table 1. Diagnostic Accuracy of Methyl- ene Blue Staining for 50 Diseased Para- thyroid Glands

No. of Glands

Detection 47/50 (94%) False negative 3 False positive 1

tween the staining and control g-roups was made in order to evaluate the different surgical techniques.

Our operative procedure for HPT due to hyperplasia involves removing all the glands and then grafting approximately 50 nag of the gland into the forearm muscle pocket, according to Wells's procedure. 6

Results of the methylene blue staining are summarized in Table t. Out o f the50 glands detected at surgery, 47 (94 per cent) were stained with methylene blue.

Three false negative glands were found, all in one patient, however, this was rather a technical failure, caused by the dye taking too long to reach the glands. A false positive gland was pathologically revealed to be a lymph node, and the thyroid gland was slightly stained on some occasions. There was one thyroid cyst intensely stained with methylene blue, however, this was easily able to be distinguished from the parathyroid gland by its macroscopic appearance.

O f the 50 glands, 47 were located in the orthotopic region, and 3 were located in the lateral surface of the carotid sheath. Two of the 13 patients were found to have more than 4 parathyroid glands. The serum cal- cium level following surgery had decreased to within the normal range in all patients in the staining group, while hypercalcemia per- sisted in 25 per cent of the control patients (3 out of t2).

Two patients complained of nausea and 3 of slight pain at the infusion site postopera- tively. One patient developed postoperative non-A, non-B hepatitis but soon recovered.

This study was limited to patients with hyperplastic parathyroid glands because of

the difficulty in detecting all the glands. Since the staining technique started being used in this department, 47 out of 50 glands (94 per cent) have been detected. This result is as satisfactory as those obtained by Bland 4 (90 per cent) and Wheeler 3 (86 per cent).

In this study, we experienced 2 cases of patients with supernumerary glands which would never have been discovered without the methylene blue staining. Small or ectopic hyperplastic glands are sometimes difficult to detect without the aid of methylene blue. ~dderstrrm 7 reported 64 cases with super- numerary glands among 503 autopsy cases (13 per cent) and Sherlock et al. 8 reported a case of a patient with a fifth parathyroid gland stained with methylene blue at the side of the carotid sheath. Such side effects as nausea and pain at an infusion site were observed in some patients, but they were not severe enough to affect the acceptability of this technique.

Since we commenced using methylene blue staining, there has been no case of pos topera t ive pe r s i s t en t hyperca lcemia , whereas before using this technique, hyper- calcemia persisted in 3 out of 12 patients (25 per cent). Although this difference is not only due to the effect of staining but also to improvements in operative technique, the staining should be highly evaluated as a useful procedure for detecting byperplastic glands in Japanese pa t ients .

(Received for publication on Mar. 1, 1988)

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Volume 18 Detection of hyperplastic parathyroid glands 731 Number 6

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