ELECTIVE CENTRAL COMPARTMENT LYMPH NODE DISSECTION DOES NOT INCREASE THE RISK OF POSTOPERATIVE HYPOPARATHYROIDISM IN PATIENTS TREATED FOR DIFFERENTIATED THYROID CANCER/ELEKTIVNA DISEKCIJA REGIJE VI NE POVECAVA RIZIK POSTOPERATIVNOG HIPOPARATIREOIDIZMA KOD BOLESNIKA LIJECENIH ZBOG DOBRO DIFERENCIRANOG KARCINOMA STITNJACE

• Published in: Acta clinica Croatica (Tisak) Vol. 59; no. S1; p. 115
• Main Authors: Stubljar, Boris, Grgic, Marija PastorCiC, Mayer, Ljiljana, Perse, Pavao, Tomicevic, Tomislav
• Format: Journal Article
• Language: English
• Published: Klinicki bolnicki centar Sestre milosrdnice 01.11.2020
• Subjects: Care and treatment; Complications; Hypoparathyroidism; Lymph nodes; Risk factors; Surgery; Thyroid cancer; Croatia
• ISSN: 0353-9466; 1333-9451
• DOI: 10.20471/acc.2020.59.s1.15

Aim: The aim of this study was to compare the incidence of postoperative hypoparathyroidism in two groups of patients who were treated for differentiated thyroid cancer. Methods: A retrospective analysis of 179 patients who were treated for differentiated thyroid cancer in our institution from January 2011 until December 2018 was performed. Only patients initially treated with total thyroidectomy and those who did not have preoperatively confirmed central compartment and lateral neck lymph node metastases were included in this study. Two main groups of patients were analysed. The patients who were treated with total thyroidectomy and elective central compartment lymph node dissection simultaneously were included in the first group. The patients who were treated only with total thyroidectomy were included in the second group. The rate of transitory and persistent postoperative hypoparathyroidism was compared between the two groups. Results: A total of 117 patients (65.4%) underwent total thyroidectomy and elective central compartment lymph node dissection simultaneously (TT + CCLNd group). The remaining 62 patients (34.6%) underwent total thyroidectomy only (TT group). A total of 22.6% patients in the TT group developed postoperative hypoparathyroidism compared with 25.6% in the TT + CCLNd group. The rate of persistent hypoparathyroidism in the TT and TT + CCLNd groups was 3.2% and 6.0%, respectively. The difference in the rate of transient and persistent postoperative hypoparathyroidism was not statistically significant between the two groups. Within the TT + CCLNd group, 82.9% of patients underwent ipsilateral paratracheal lymph node dissection and 17.1% underwent bilateral paratracheal lymph node dissection. The rate of postoperative hypoparathyroidism was analysed in those two subgroups of patients and did not prove to be statistically significant. Discussion: While its impact on the local recurrence rate is still controversial, elective central compartment lymph node dissection could be a great tool for selection of patients who could profit from adjuvant radioiodine treatment. On the other hand, central compartment lymph node dissection could potentially increase the risk of hypoparathyroidism due to involuntary injury to parathyroid glands and/or their blood supply. Our study did not find a statistically significant difference regarding postoperative hypoparathyroidism between patients who underwent central compartment lymph node dissection compared with patients who underwent total thyroidectomy only. Our data are not in accordance with some of the previously published studies. Conclusion: Our results demonstrated that elective central compartment lymph node dissection is a safe procedure and does not significantly increase the risk of postoperative hypoparathyroidism when it is performed simultaneously with total thyroidectomy. Key Words: differentiated thyroid cancer, total thyroidectomy, central compartment lymph node dissection, paratracheal dissection, postoperative hypoparathyroidism Cilj rada je usporediti incidenciju postoperativnog hipoparatireoidizma izmectu dvije skupine bolesnika lijecenih zbog dobro diferenciranog karcinoma stitnjace. Metode: Retrospektivno smo analizirali 179 bolesnika koji su u nasoj ustanovi lijeceni zbog dobro diferenciranog karicnoma stitnjace u periodu od sijecnja 2011 do prosinca 2018. U studiju su bili ukljuceni samo bolesnici kod kojih je inicijalno ucinjena totalna tiroidektomija te oni koji na osnovu preoperativne obrade nisu imali potvrcene metastaze na lateralnom vratu i u regiji VI. Analizirane su dvije skupine bolesnika. U prvu skupinu su ukljuceni bolesnici kod kojih je u istom aktu ucinjena totalna tireoidektomija i disekcija regije VI. Svi ostali bolesnici kod kojih je ucinjena samo totalna tireoidektomija ukljuceni su u drugu skupinu. Stopa tranzitornog i trajnog hipoparatireoidizma je usporectivana izmectu dvije skupine. Rezultati: Kod ukupno 117 bolesnika (65,4%) ucinjena je disekcija regije VI istodobno s totalnom tireoidektomijom. (TT + CCLNd skupina). Kod preostalih 62 bolesnika (34,6%) ucinjena je samo totalna tireoidektomija. (TT skupina). Ukupno 22,6% bolesnika iz TT skupine je razvilo postoperativni hipoparatireoidizam usporedno s 25,6% bolesnika iz TT + CCLNd skupine. Stope trajnog hipoparatireoidizma u TT i TT + CCLNd skupinama su iznosile 3,2 i 6 %. Stopa tranzitornog kao i trajnog postoperativnog hipoparatireoidizma nije bila statisticki znacajna izmecu dvije skupine. Unutar TT + CCLNd skupine, kod 82,9% bolesnika je ucinjena disekcija ipsilateralnih paratrahealnih limfnih cvorova, za razliku od 17,1% bolesnika kod kojih je ucinjena disekcija bilateralnih paratrahealnih cvorova. Stopa postoperativnog hipoparatireoidizma je analizirana u dvjema podskupinama i nije se pokazala statisticki znacajnom. Rasprava: Iako je utjecaj elektivne disekcije regije VI na lokoregionalno recidiviranje i dalje kontroverzan, ona moze biti odlican alat za probir bolesnika koji mogu imati korist od adjuvantne radiojodne ablacije. S druge strane, disekcija regije VI potencijalno moze povecati rizik hipoparatireoidizma zbog nenamjerne ozljede dostitnih zlijezda ili/i njihove krvne opskrbe. Nasa studija nije pokazala statisticki znacajnu razliku u stopi postoperativnog hipoparatireoidizma izmectu skupine bolesnika kod kojih je ucinjena disekcija regije VI u usporedbi sa skupinom bolesnika kod kojih je ucinjena samo totalna tireoidektomija. Nasi podaci su u proturijecju s nekim ranije publiciranim studijama. Zakljucak: Nasi rezultati su pokazali da je elektivna disekcija regije VI sigurni postupak i znacajno ne povecava rizik postoperativnog hipoparatireoidizma kada se izvodi istodobno s totalnom tireoidektmijom. Kljucne rijeci: dobro diferencirani karcinom stitnjace, totalna tiroidektomija, disekcija regije VI, paratrahealna disekcija, postoperativni hipoparatireoidizam