ORIGINAL ARTICLE
Predictive factors for difficult robotic thyroidectomy using the bilateral axillo-breast approach Hee Yong Kwak, MD, PhD, Hoon Yub Kim, MD, PhD,* Hye Yoon Lee, MD, PhD, Seung Pil Jung, MD, PhD, Sang Uk Woo, MD, PhD, Gil Soo Son, MD, PhD, Jae Bok Lee, MD, PhD, Jeoung Won Bae, MD, PhD Department of Surgery, Korea University College of Medicine, Seoul, Korea.
Accepted 14 May 2015 Published online 20 August 2015 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/hed.24135
ABSTRACT: Background. The purpose of this study was to identify predictors of difficult robotic thyroidectomy using the bilateral axillo-breast approach (BABA) for the management of patients with papillary thyroid carcinoma (PTC). Methods. We examined a database containing details of patients with PTC who had undergone robotic thyroidectomy with cervical lymph node dissection between July 2008 and June 2013. Patients were subgrouped into difficult thyroidectomy and non-difficult thyroidectomy to identify predictors associated with difficult thyroidectomy corresponding to the time of operation. Clinicopathologic characteristics, surgical outcomes, and postoperative morbidities were investigated. Results. Male sex was the only significantly different clinicopathologic factor between the 2 groups (p 5 .013). Other factors, such as age (p 5 .809) and body mass index (BMI; p 5 .202), were comparable between the 2 groups. The rates of postoperative complications, such as
hypoparathyroidism, vocal cord palsy, and seroma, in the difficult thyroidectomy group were not significantly different from those in the nondifficult thyroidectomy group. There was no hematoma or wound infection. Male sex was the only independent factor associated with difficult thyroidectomy (odds ratio [OR] 5 5.379; 95% confidence interval [CI] 5 1.052–27.502; p 5 .043), according to the multivariate logistic regression model. Conclusion. Male sex was the only predictive factor for difficult robotic thyroidectomy using BABA. Further evaluations should be performed to ascertain additional factors associated with difficult robotic thyroidecC 2015 Wiley Periodicals, Inc. Head Neck 38: E954–E960, 2016 tomy. V
INTRODUCTION
As the experience of surgeons in robotic surgery grows, the ability to perform robotic thyroidectomy has also developed. Nevertheless, most surgeons still believe that ideal patients for this procedure are thin female patients with a small unilateral nodule (25 kg/m2 Preoperative size >1 cm Predicted thyroiditis
p value
OR
95% CI
.032 .203 .230 .190 .793
6.217 0.516 1.090 1.656 1.155
1.168–33.100 0.186–1.430 0.947–1.255 0.779–3.520 0.393–3.394
Abbreviations: OR, odds ratio; CI, confidence interval; BMI, body mass index.
FIGURE 2. The decreased volume of redundant breast tissue makes an angle limitation when the camera port and other arms approach the field of operation in men (A), as compared with women (B). Hence, a slight Trendelenburg’s position for robotic arms was created to cross over the clavicle as a solution for retaining an adequate angle and field of operation in men.
longer time to tunnel a flap, has an angle limitation when the camera port and other arms approach the field of operation (see Figure 2), and has a limitation in the range of motion of the robotic arms in performing robotic thyroidectomy using BABA. In male patients, we created a slight Trendelenburg’s position for robotic arms to cross over the clavicle as a solution for retaining an adequate angle and field of operation. This method is still used at our institution. Thyroiditis is a common disease of the thyroid, in which the immune system primarily reacts against a variety of thyroid antigens.20 Therefore, in humans, the physiological processes to prevent tissue damage results in inflammation. It is well known that thyroiditis is potentially a risk factor causing difficult thyroid surgery.21,22 However, we found no significant difference in thyroiditis between difficult thyroidectomy and non-difficult thyroidectomy in the current study (OR 5 1.155; 95% CI 5 0.393–3.394; p 5 .793). Obese patients are not usually regarded as adequate candidates for robotic thyroidectomy.13 In this study, HEAD & NECK—DOI 10.1002/HED
APRIL 2016
E959
KWAK ET AL.
although patients in the difficult thyroidectomy group tended to be more obese than those in the non-difficult thyroidectomy group, the difference in the number of obese patients was not significant (24.01 6 3.37 vs 22.84 6 3.99; p 5 .451). We speculate that this might be because the average body size of Asians is smaller than that of Westerners, and that Asians have lesser body fat. In fact, obesity is regarded as a BMI >25 kg/m2 in Korea and only 5 of the 94 patients in the subgroup analysis showed BMI >30 kg/m2 in our study. With regard to adequate lymph node dissection, our data revealed that the number of retrieved lymph nodes (7.40 6 6.13 nodes vs 5.65 6 4.42; p 5 .226) and metastatic lymph nodes (1.30 6 1.91 nodes vs 0.88 6 1.22; p 5 .125) were larger and the lymph node ratio was lower in difficult thyroidectomy than non-difficult thyroidectomy (0.17 6 0.27 vs 0.18 6 0.27; p 5 .830) without significant difference, indicating that the status of lymph nodes does not affect the duration of robotic total thyroidectomy. The incidence of transient (p 5 .201) and permanent hypoparathyroidism (p 5 .380) did not differ between the 2 groups, although they had slightly smaller values. The incidence of either transient or permanent vocal cord palsy was even smaller, but, again, no significant difference between the 2 groups was noted because of the large deviations. These results are comparable to those of previous studies reporting that transient hypocalcemia levels after open thyroidectomy ranged from 0.3% to 49% and permanent hypocalcemia levels ranged from 0% to 13%.23 In addition, the incidence of transient vocal cord palsy previously ranged from 0% to 6%, and the incidence of permanent vocal cord palsy was
Predictive factors for difficult robotic thyroidectomy using the bilateral axillo-breast approach Hee Yong Kwak, MD, PhD, Hoon Yub Kim, MD, PhD,* Hye Yoon Lee, MD, PhD, Seung Pil Jung, MD, PhD, Sang Uk Woo, MD, PhD, Gil Soo Son, MD, PhD, Jae Bok Lee, MD, PhD, Jeoung Won Bae, MD, PhD Department of Surgery, Korea University College of Medicine, Seoul, Korea.
Accepted 14 May 2015 Published online 20 August 2015 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/hed.24135
ABSTRACT: Background. The purpose of this study was to identify predictors of difficult robotic thyroidectomy using the bilateral axillo-breast approach (BABA) for the management of patients with papillary thyroid carcinoma (PTC). Methods. We examined a database containing details of patients with PTC who had undergone robotic thyroidectomy with cervical lymph node dissection between July 2008 and June 2013. Patients were subgrouped into difficult thyroidectomy and non-difficult thyroidectomy to identify predictors associated with difficult thyroidectomy corresponding to the time of operation. Clinicopathologic characteristics, surgical outcomes, and postoperative morbidities were investigated. Results. Male sex was the only significantly different clinicopathologic factor between the 2 groups (p 5 .013). Other factors, such as age (p 5 .809) and body mass index (BMI; p 5 .202), were comparable between the 2 groups. The rates of postoperative complications, such as
hypoparathyroidism, vocal cord palsy, and seroma, in the difficult thyroidectomy group were not significantly different from those in the nondifficult thyroidectomy group. There was no hematoma or wound infection. Male sex was the only independent factor associated with difficult thyroidectomy (odds ratio [OR] 5 5.379; 95% confidence interval [CI] 5 1.052–27.502; p 5 .043), according to the multivariate logistic regression model. Conclusion. Male sex was the only predictive factor for difficult robotic thyroidectomy using BABA. Further evaluations should be performed to ascertain additional factors associated with difficult robotic thyroidecC 2015 Wiley Periodicals, Inc. Head Neck 38: E954–E960, 2016 tomy. V
INTRODUCTION
As the experience of surgeons in robotic surgery grows, the ability to perform robotic thyroidectomy has also developed. Nevertheless, most surgeons still believe that ideal patients for this procedure are thin female patients with a small unilateral nodule (25 kg/m2 Preoperative size >1 cm Predicted thyroiditis
p value
OR
95% CI
.032 .203 .230 .190 .793
6.217 0.516 1.090 1.656 1.155
1.168–33.100 0.186–1.430 0.947–1.255 0.779–3.520 0.393–3.394
Abbreviations: OR, odds ratio; CI, confidence interval; BMI, body mass index.
FIGURE 2. The decreased volume of redundant breast tissue makes an angle limitation when the camera port and other arms approach the field of operation in men (A), as compared with women (B). Hence, a slight Trendelenburg’s position for robotic arms was created to cross over the clavicle as a solution for retaining an adequate angle and field of operation in men.
longer time to tunnel a flap, has an angle limitation when the camera port and other arms approach the field of operation (see Figure 2), and has a limitation in the range of motion of the robotic arms in performing robotic thyroidectomy using BABA. In male patients, we created a slight Trendelenburg’s position for robotic arms to cross over the clavicle as a solution for retaining an adequate angle and field of operation. This method is still used at our institution. Thyroiditis is a common disease of the thyroid, in which the immune system primarily reacts against a variety of thyroid antigens.20 Therefore, in humans, the physiological processes to prevent tissue damage results in inflammation. It is well known that thyroiditis is potentially a risk factor causing difficult thyroid surgery.21,22 However, we found no significant difference in thyroiditis between difficult thyroidectomy and non-difficult thyroidectomy in the current study (OR 5 1.155; 95% CI 5 0.393–3.394; p 5 .793). Obese patients are not usually regarded as adequate candidates for robotic thyroidectomy.13 In this study, HEAD & NECK—DOI 10.1002/HED
APRIL 2016
E959
KWAK ET AL.
although patients in the difficult thyroidectomy group tended to be more obese than those in the non-difficult thyroidectomy group, the difference in the number of obese patients was not significant (24.01 6 3.37 vs 22.84 6 3.99; p 5 .451). We speculate that this might be because the average body size of Asians is smaller than that of Westerners, and that Asians have lesser body fat. In fact, obesity is regarded as a BMI >25 kg/m2 in Korea and only 5 of the 94 patients in the subgroup analysis showed BMI >30 kg/m2 in our study. With regard to adequate lymph node dissection, our data revealed that the number of retrieved lymph nodes (7.40 6 6.13 nodes vs 5.65 6 4.42; p 5 .226) and metastatic lymph nodes (1.30 6 1.91 nodes vs 0.88 6 1.22; p 5 .125) were larger and the lymph node ratio was lower in difficult thyroidectomy than non-difficult thyroidectomy (0.17 6 0.27 vs 0.18 6 0.27; p 5 .830) without significant difference, indicating that the status of lymph nodes does not affect the duration of robotic total thyroidectomy. The incidence of transient (p 5 .201) and permanent hypoparathyroidism (p 5 .380) did not differ between the 2 groups, although they had slightly smaller values. The incidence of either transient or permanent vocal cord palsy was even smaller, but, again, no significant difference between the 2 groups was noted because of the large deviations. These results are comparable to those of previous studies reporting that transient hypocalcemia levels after open thyroidectomy ranged from 0.3% to 49% and permanent hypocalcemia levels ranged from 0% to 13%.23 In addition, the incidence of transient vocal cord palsy previously ranged from 0% to 6%, and the incidence of permanent vocal cord palsy was
