HARMONIC SCALPEL POSSIBILITIES IN THE SURGICAL TREATMENT OF SECONDARY HYPERPARATHYROIDISM

The significant changes in coagulation status during chroniodialysis, performed in patients with secondary hyperparathyroidism require completion of meticulous surgical hemostasis in order to prevent active bleeding in the postoperative period. Aim: To present our experience with harmonic scalpel application in the surgical treatment of secondary hyperparathyroidism. Patients and Methods: 112 patients with secondary hyperparathyroidism (77 males and 35 females, aged from 23 to 60 years) have been operated on in our institution for 10 years period. All patients were on chroniodialysis. Hemostasis was achieved using conventional instruments and electrocautery in 46 patients and in 66 patients harmonic scalpel of Ethicon EndoSurgeryCare has been used. All patients had serum levels of parathormone above 2500ng/l. Ultrasonic examination revealed at least 2 parathyroid glands larger than 10mm in all cases. The amount of blood loss, necessity and type of drainages used, frequency of postoperative complications, postoperative hospital stay were comparatively evaluated. Results: In 12 patients parathyroidectomy with autotransplantation was carried out, in 62 patients subtotal parathyroidectomy was performed. In the rest 35 casesthree of the parathyroid glands were removed (because of the impossibility to identify the fourth parathyroid gland, using ultrasonic and intraoperative methods). All patients were proven to have a sharp decrease in parathormone and Calcium serum levels. In the group of patients, where conventional instruments and electrocautery for hemostasis have been used, corrugated and tube drainages were applied as a rule. For the patients, in whom hemostasis was performed using a harmonic scalpel, simple glove drainages were used. In all patients in the preoperative and post-operative period serial hemodialysis was done with LMW heparin administration. Significantly lower blood loss from the surgical wound was found in the group, where harmonic scission was used. Conclusions: We consider that the application of harmonic scalpel in the surgical treatment of patients with secondary hyperparathyroidism on chroniodialysis leads to safer hemostasis, lower postoperative complications rate and thus shortens the postoperative hospital stay.

The secondary hyperparathyroidism (SHPT) is a common complication in patients with chronic renal failure.Around 40% of patients on chroniodialysis, after a 15 years period undergo parathyroidectomy 1 .During the last 30 years several surgical strategies for the treatment of SHPT were developed: subtotal parathyroidectomy was first published by Stanbury et al. in 1960 [2], total parathyroidectomy by Ogg in 1967 [3] and total parathyroidectomy with autotransplantation by Geis et al. in 1973 [4].
The surgical treatment requires completion of meticulous surgical hemostasis in order to prevent active bleeding as a consequence of the changes in coagulation status during dialysis.This paper aims to present the experience of our institution with harmonic scalpel application in the surgical treatment of SHPT.

PATIENTS AND METHODS
For a 10 years period 112 patients with secondary hyperparathyroidism (77 males and 35 females, aged from 23 to 60 years) underwent surgery in our clinic.All patients have been on chroniodialysis since one to fifteen years before the procedure.
In 46 patients the surgical treatment and hemostasis were performed using conventional equipment and in 66using harmonic scalpel (Ethicon EndoSurgery Care) /Fig.All patients had serum levels of parathormone above 2500 ng/L.Ultrasonography revealed at least two parathyroid glands, above 10 mm in size.
Comparative assessment of intraoperative blood loss, quality of achieved hemostasis, necessity and type of used drainages, rate of postoperative complications and length of postoperative hospital stay has been made.

RESULTS
In 77 patients 4 to 6 hyperplastic parathyroid glands have been detected, from 7 to 25 mm in size /Fig.2/.In the remaining 35 cases three parathyroid glands have been removed because of inability to identify the fourth parathyroid during the diagnostic evaluation or intraoperatively (Table 1).
In the patients group where conventional instruments and electrocautery have been used, the degree of hemostasis was worse, which lead to the need from corrugated or tubular drainages, usually removed after the second postoperative dialysis.In the group with harmonic scalpel use, the intraoperative hemostasis is much better and there was no need for vessel ligatures and the procedure finished as a rule with insertion of gloves drainages.The bleeding established after the first postop dialysis was significantly larger in the group with conventional instruments and electrocautery.The monitoring of serum levels of parathormone and calcium on the 24 th hour demonstrated sharp decrease in their values.
The discharge from the hospital in the group with conventional instruments and electrocautery was not earlier than after the second postoperative dialysis and in the harmonic scalpel group it occurred earlier -after the first postoperative dialysis.

DISCUSSION
Secondary hyperparathyroidism is a mineral homeostasis disturbance predominantly in patients with chronic renal diseases [5, 6, 7].As a consequence of the renal failure, retention of phosphates, vitamin D deficiency and hypocalcaemia occur, leading to pathological increase in parathormone secretion [7].
The pathogenesis of this parathyroid disease is not sill completely clear.In the earlier stage of the disease a polyclonal hyperplasia of parathyroid cells is usually found.For later stages of secondary hyperparathyroidism neoplastic transformation of preexisting polyclonal hyperplasia to monoclonal zones is typical which probably plays leading role in the course of the disease.
Total parathyroidectomy is recommended in patients with hyperparathyroidism refractory to medical treatment [5,8].
The indications to perform parathyroidectomy are still not well defined.There is a lack of studies, which could undoubtedly point the biochemical markers of lack of efficiency from the medicated treatment and requiring surgical intervention to control the hyperparathyroidism.Classic indication for surgical parathyroidectomy is the medication treatment resistant hypercalcemia and hyperphosphatemia in combination with severe hyperparathyroidism (erum level of PTH 8 fold above the normal range).The severe hypercalcemia with PTH above 55 pmol/l is still considered an absolute indication for parathyroidectomy [9, 10].The objectives of the surgical treatment of secondary hyperparathyroidism are to eliminate the symptoms of PTH overproduction, meanwhile escaping the postoperative hypocalcemia as a result of the lack of parathyroid tissue.
Two main surgical techniques are in use: Subtotal parathyroidectomy and total parathyroidectomy with autotransplantation.
The total parathyroidectomy without autotransplantation would result in a complete deficiency of parathormone, which requires lifelong substitution with calcium and vitamin D and may have significant impact on the bone mineralization.That is the reason for this technique has been abandoned by most of the surgeons [5].
To reach the posterior surface of the thyroid gland where the parathyroids are located, particularly precise and bloodless dissection is necessary, in the situation of impaired coagulation status.
The success of the surgical treatment depends exceptionally on: 1) the successful identification of all parathyroid glands and 2) the possibility to leave an optimal amount of remnant parathyroid tissue.
Leaving parathyroid remnants in an exceeding or insufficient amount may lead to serious complications or recurrence of the SPTH [1]

Fig. 1 .
Fig. 1.Distribution of patients with hyperparathyroidism operated on with conventional instruments and with harmonic scalpel.
. Maximal success in the Extent of surgical intervention using conventional equipment and harmonic scalpel.