Thyroidectomy is the partial or total surgical removal of the thyroid gland. A large goiter is defined as having a volume exceeding 100 grams (g). Normal thyroid volume is difficult to determine and varies by region and local iodine status. Until 1950, a normal thyroid was estimated between 20 and 25 g, with an upper limit of 35 g. More recently, studies conducted in countries with sufficient iodine intake have estimated the normal thyroid weight to be 10 g, with an upper limit of 20 g [1][2].

Large goiters are common in regions where iodine deficiency is endemic. They cause a challenge for surgeons due to the anticipated risk of difficult dissection and the increase of surgical complications. Similarly, they are a source of concern for anesthesiologists due to anticipated intubation difficulties and the risk of post-thyroidectomy tracheomalacia. In this study, we aimed to present our experience in managing large goiters, describing our tips and techniques for thyroidectomy.

Due to their prevalence and potential complications, thyroid disorders constitute a significant global public health issue. The prevalence of goiters, nodules, and thyroid cancers continues to rise, particularly in developing countries where iodine deficiency disorders persist [3]. A large goiter (marked thyroid enlargement) carries the risk of compressing the aero digestive tract (causing dyspnea and dysphagia) and the laryngeal nerves (causing dysphonia). Non-toxic goiters often progress to hyperthyroidism [4]. Multinodular goiter represents the advanced stage of an untreated goiter; it is characterized by nodular heterogeneity resulting from the formation of new follicles and alterations of the vascular network, leading to hyper vascular goiters that are prone to hemorrhage.

In the Democratic Republic of the Congo (DRC), thyroid disorders remain common related to iodine deficiency; despite recent efforts toward national iodine supplementation. The gradual development of endocrine surgery services in hospitals, particularly in urban areas, has led to significant improvements in the surgical management and follow-up of patients with thyroid disorders. However, such specialized care is virtually non-existent in rural areas and in most provinces of the DRC [5][6].

The surgical technique for thyroidectomy is well standardized. A distinction is made between the conventional procedure used for the removal of large goiters and the video-assisted technique employed for the removal of small multinodular goiters, which offers an aesthetic advantage (a 2 to 2.5 cm scar) [7]. The conventional technique, which is the most widely used in developing countries, faces three major challenges when dealing with large goiters:

Difficult access to the superior pole of the thyroid for the ligation and division of the superior thyroid arteries;Due to poor exposure, enucleation of large lateral lobes is difficult or even impossible, as they are buried beneath the superficial cervical fascia and the sternocleidomastoid muscles. Consequently, the tearing of vessels that have not been identified and ligated during operative maneuvers leads to massive hemorrhage, endangering the patient’s life.Dissection difficulties resulting from cutaneous-aponeurotic fibrosis associated with long-standing goiters and indigenous treatments (scarification, massage, application of hot poultices, etc.).

Due to these technical challenges, we addressed the following question:

What tips and techniques are best suited for large goiters in the endemic areas?

We performed 104 thyroidectomies over a two-year period, representing an average of 52 cases per year.

The mean age of the patients was 35 ± 6 years. The majority of patients (37.5%) fell within the 40 - 50 age groups, with a peak between 31 and 60 years and a range of 20 to 80 years. Patient age alone is generally not an absolute contraindication for thyroidectomy. Surgeons frequently perform the procedure safely on both paediatric and geriatric populations. However, age often influences the indications for surgery and may present specific relative contraindications or elevated risk factors [8].

The female population was the most affected by goiter (95.2%). The predominance of thyroid disease in women has been reported by other authors [9]-[11]. This clinical situation is linked to the presence of estrogen receptors on thyroid cells which promote the development of goiter during hormonal surges (puberty, pregnancy, and menopause) as well as to iodine deficiency, as iodine requirements increase during pregnancy.

Total thyroidectomy was the most frequently performed procedure (68.3%) for large multinodular goiters, followed by cases of simple goiter (13 patients, 12.5%) and thyroid cancer (3 patients, 2.8%). These indications are consistent with most recent literature [12]-[14]. The majority of large goiters (83.7%) were operated on using the cervicotomy technique at the junction of the lower and middle thirds, combined with a cruciform aponeurotomy. The conversion rate for conventional thyroidectomy was 9.6%. Total thyroidectomy offers the advantage of providing radical, definitive treatment for the goiter, with no risk of recurrence. In our context, it is justified by the unavailability of intraoperative biopsy, the late management of thyroid diseases, and the limited use of minimally invasive techniques

We found a positive correlation between the duration and volume of the goiter (r = 1; p = 0.042). The largest volume of goiter in the series was 980 g, associated with duration of 42 years at a patient of 73 years old. The mean duration of goiters was 15 years. There is a linear positive correlation between the duration of goiters and thyroid volume, with the increasing of 4.5% per year [14][15]. This gradual increase, due to the persistence of growth factors, raises the risk of compressive symptoms and nodular transformation over time.

About 93% of patients underwent indigenous treatment before surgery (thyroid massage, poultices, and scarification). These practices, common in areas of endemic goiter in the DR Congo, trigger an inflammatory reaction leading to fibrosis of the cutaneous, fascial, and thyroid structures, thereby increasing the difficulty of dissection.

The majority of large goiters (83.7%) were operated on using a cervicotomy procedure performed at the junction of the lower and middle thirds, combined with a cruciform aponeurotomy. The conversion rate for Kocher cervicotomy was 9.6%. Our results differ from those of Gardner (Edinburgh, 1995), who performed 474 thyroidectomies for large goiters, including 47 total thyroidectomies (10%) [16][17]. This difference is likely attributable to the difficulty of performing a total thyroidectomy using the conventional procedure (Kocher’s thyroidectomy) in cases of large goiters.

Most complications were minor. We observed 4 cases (3.8%) of acute hemorrhage intraoperatively and 2 of them (0.9%) required blood transfusion, there were no cases of reoperation. There were 2 cases (0.9%) of dysphonia; no transient recurrent laryngeal nerve palsy was observed. 3 cases of hypocalcemia (2.8%) and 1 death (0.9%). This result differs from that of CATHY study [18], which reported 8% of recurrent laryngeal nerve palsy. We believe this discrepancy may be due to the fact that we relied solely on voice assessment rather than nerve monitoring to detect recurrent laryngeal nerve palsy. The same study indicates a relationship between surgeon experience and the rate of postoperative complications.

Large goiters are common in regions with endemic iodine deficiency and cause technical challenges for surgeons due to the anticipated difficulty of dissection and the increase of surgical complications. A cervicotomy performed at the junction of the middle and lower thirds, combined with a cruciform aponeurotomy and transverse section of the infrahyoid muscles, provides excellent exposure and facilitates dissection, thereby reducing both perioperative and long-term postoperative complications.

Age of the patients (year), Indications of thyroidectomy (%), weight of specimens (g), duration of goiter (year), treatment prior to thyroidectomy (%), Surgical procedures (%), Surgical complications (%).

We thank all the authors for their contribution to this article.

DKR developed the study protocol, collected, analyzed the data and wrote the first draft of manuscript. MMD reviewed Methods and Materials, made critical revision of the manuscript according to scientific point of view. LJ organized the study framework and availability of surgical instruments.

The datasets used and analyzed during the current study are available from the corresponding author and can be verified on request.

We obtained approval from the Medical Ethics of Provincial Health administration N˚221/CAB/MINIPRO/SP-TPS-FP/N-UB/DBC/2022, and the authorization of Nord-Ubangi and Sud-Ubangi Provincial Divisions of Health.

DRC: Democratic Republic of Congo, WHO: World Health Organization, HZ: Health Zone, T4: Tetra-iodo-thyroxine, T3: Tri-iodo-thyronine.