Case Report Double Recurrent Laryngeal Nerve with Thyroid Carcinoma Ann. Ital. Chir., 2024 95, 3: 281–283 https://doi.org/10.62713/aic.3305 281 Ann. Ital. Chir., 95, 3, 2024 Ugur Kesici 1 , Mehmet Guray Duman 1 , Ahmet Furkan Mazlum 2 , Leman Damla Ercan 2 1 Department of General Surgery, Prof. Dr. Cemil Tascioglu City Hospital, University of Health Sciences, 34384 Istanbul, Türkiye 2 Department of General Surgery, Sultan II. Abdulhamid Han Training and Research Hospital, University of Health Sciences, 34380 Istanbul, Türkiye The most important and serious complication of thyroid surgery is recurrent laryngeal nerve (RLN) injury, and it has been noted that this risk increases considerably in the presence of anatomical variations. Double recurrent laryngeal nerve (DRLN) is very rare among RLN anatomical variations. There are only a few case reports on DRLN in the literature It is crucial to possess surgical expertise and ensure complete visualization of the nerve to minimize the likelihood of RLN injury. Intraoperative nerve monitoring (IONM) is particularly useful in identifying anatomical variations. In a 54-year-old woman undergoing diagnostic left lobectomy+isthmectomy, a left DRLN was identified during intraoperative exploration and meticulous nerve exploration with the assistance of IONM monitoring verified that the impulse conduction in both branches was identical. The surgical procedure was successfully performed without causing any harm to the nerve. Based on the case reports in the literature and our experience with this patient, we believe that surgical expertise and the utilization of IONM can decrease RLN nerve damage and reveal its anatomical variations during thyroid surgery. Keywords: double recurrent laryngeal nerve; thyroid; carcinoma; nerve; intraoperative nerve monitoring Introduction Thyroidectomy is frequently performed for diffuse toxic goiter (Graves’ disease), toxic multinodular goiter (Plum- mer disease); for benign thyroid diseases with symptoms like dysphagia, dyspnea, voice change, neck discomfort, and also for thyroid malignancies [1, 2, 3]. One of the most important and serious complications of thyroid surgery is recurrent laryngeal nerve (RLN) injury. The RLN normally arises from the vagus nerve in the upper mediastinum. It traverses the tracheoesophageal sulcus and enters the lar- ynx lateral to the Berry ligament. It innervates all intrinsic laryngeal muscles except the cricothyroid muscle. The key steps in thyroid surgery are the identification and conserva- tion of the RLN [4, 5]. The RLN has many anatomical vari- ations, more frequently on the right side than on the left [4]. Hence, good dissection and thorough visualization during surgery are crucial for protecting nerves and ensuring surgi- cal safety [6]. Double recurrent laryngeal nerve (DRLN) is very rare among RLN anatomical variations. There are only a few case reports in the literature [4, 6, 7]. RLN damage causes various problems, from voice changes to respiratory failure Identifying variations such as DRLN is important to reduce the risk of intraoperative RLN damage [4]. Intraop- erative nerve monitoring (IONM) is used by most thyroid surgeons IONM contributes to the recognition of RLN in- jury, identification of its anatomical variations and reduc- Correspondence to: Ugur Kesici, Department of General Surgery, Prof. Dr. Cemil Tascioglu City Hospital, University of Health Sciences, 34384 Istanbul, Türkiye (e-mail: ugurkesici77@mynet.com). tion of the risk of damage [8]. We report a case of DRLN identified in a female patient during diagnostic left lobec- tomy+isthmectomy. Case Report Written informed consent for scientific study was obtained from the patient. The patient was a 54-year-old woman who complained of swelling in the neck for one year. Dur- ing the neck examination, a well-defined and mobile nod- ule measuring approximately 30 × 20 mm was detected in the left lobe of the thyroid gland. Ultrasound examination of the patient’s neck revealed the presence of several hy- poechoic solid nodules, with the largest measuring 40 × 25 mm, in the left lobe. The patient’s thyroid function tests were within the normal limits. The ultrasound-guided fine needle aspiration cytology performed on the 40 × 25 mm nodule in the left lobe revealed a typical follicular cytology of unknown significance. Informed consent was obtained from the patient and she underwent diagnostic left lobec- tomy+isthmectomy due to the 40 mm size of the left lobe nodule and Bethesda 3 cytology. During intraoperative ex- ploration, the left DRLN was identified (Fig. 1) and IONM verified that the impulse conduction in both branches was identical. There were no complications and the patient was discharged on the first postoperative day. Based on the pathology results, the patient was diagnosed with four focal papil- lary carcinoma oncocytic variants, measuring 35 mm, 10 mm, 4 mm, and 4 mm. Therefore, it was decided to ad- minister radioactive iodine (RAI) treatment. The patient underwent completion thyroidectomy in a second proce-