Total endoscopic thyroidectomy versus conventional open thyroidectomy in thyroid cancer: a systematic review and meta-analysis

Figures & data

Figure 1 Flow diagram for study selection.

Abbreviation: FTC, follicular thyroid cancer.

Table 1 General characteristics of studies included in the meta-analysis

Study (first author, year)	Region	Study type	No of patients		Age (years), mean ± SD ET OT		Gender, M/F		Extent of thyroidectomy, TT/LTT		Surgical approach	Matchinga	Quality score
			ET	OT	ET	OT	ET	OT	ET	OT
Chung 2007^Citation26	Korea	RS	103	198	38.2±8.2	47.2±10.2	1/102	25/173	88/15	172/26	BABA	4, 9	6
Hong 2011^Citation27	Korea	RS	57	60	39.60±7.88	41.77±9.61	6/51	11/49	0/57	0/60	BABA/UABA	1, 2, 4, 7, 9	7
Kim 2011^Citation28	Korea	RS	95	138	39.9±9.1	51.8±8.9	2/93	34/104	95/0	138/0	BABA	9	6
Tae 2011^Citation29	Korea	RS	31	36	36.2±9.9	44.6±11.8	1/30	11/25	3/28	0/36	UABA/TAA	4–9	7
Lee 2012^Citation30	Korea	RS	37	41	42.3±7.6	49.0±10.8	0/37	3/38	0/37	0/41	TAA	2, 4, 5, 7–9	7
Tan 2015^Citation31	China	RS	34	30	30 (16–44)b	43 (25–76)b	2/32	4/26	0/34	0/30	BBA	2, 4, 9	7
Huang 2016^Citation7	China	RS	75	123	37.8±10.6	39.2±11.3	16/59	31/92	75/0	123/0	TAA	1–5, 7–9	7
Kim 2016^Citation32	Korea	RS	173	830	38.90 (17–57)b	49.53 (17–84)b	13/160	96/734	56/117	684/146	BABA	2	5
Lee 2016^Citation33	Korea	RS	75	233	42.2±8.6	52.1±9.3	3/72	15/218	0/75	0/233	BABA/UABA	2, 4, 5, 7, 9	6
Park 2016^Citation34	Korea	RS	50	102	38.0±9.4	50.8±11.5	4/46	14/88	50/0	102/0	UABA	2, 4–7, 9	5
Xiang 2016^Citation35	China	RS	49	47	34.2±7.0	46.9±13.3	0/49	6/41	49/0	47/0	BBA	7, 9	6
Ren 2017^Citation36	China	RS	20	35	36.05±7.536	36.06±5.646	0/20	0/35	0/20	0/35	BBA	1–3, 9	6

Notes:

a Features matching ET and OT: 1 = age; 2 = gender; 3 = body mass index; 4 = tumor size; 5 = multiplicity; 6 = bilaterality; 7 = extrathyroidal extension; 8 = tumor stage; 9 = extent of thyroidectomy.

b Median (range).

Abbreviations: BABA, bilateral axillobreast approach; BBA, bilateral breast approach; ET, endoscopic thyroidectomy; F, female; LTT, less than total thyroidectomy; M, male; OT, open thyroidectomy; RS, retrospective study; TAA, transaxillary approach; TT, total thyroidectomy; UABA, unilateral axillobreast approach.

Table 2 Pathological characteristics of studies included in the meta-analysis

Study (first author, year)	Tumor size (mm)		Multiplicity (n/N)		Bilaterality (n/N)		Extrathyroidal extension (n/N)		Positive LNs (n/N)		No of metastatic LNs
	ET	OT	ET	OT	ET	OT	ET	OT	ET	OT	ET	OT
Chung 2007^Citation26	<10	<10	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR
Hong 2011^Citation27	7.25±2.30	7.10±2.65	NR	NR	NR	NR	10/57	19/60	21/57	26/60	1.30±1.83	1.43±1.87
Kim 2011^Citation28	6.0±2.0	7.0±2.0	NR	NR	NR	NR	NR	NR	NR	NR	0.9±2.0	0.5±0.9
Tae 2011^Citation29	7.6±4.9	6.4±2.3	2/31	2/36	0/31	0/36	2/31	1/36	4/16	2/12	NR	NR
Lee 2012^Citation30	5.0±2.31	4.1±2.64	3/37	5/41	NR	NR	1/37	2/41	5/37	1/41	NR	NR
Tan 2015^Citation31	7.0±3.0	8.0±4.0	NR	NR	NR	NR	NR	NR	8/34	4/30	0.8±2.0	0.2±0.7
Huang 2016^Citation7	4.8±1.9	4.9±2.3	5/75	9/123	NR	NR	2/75	4/123	9/75	11/123	NR	NR
Kim 2016^Citation32	NR	NR	NR	NR	NR	NR	4/173	128/830	34/173	312/830	NR	NR
Lee 2016^Citation33	5.8±3.5	6.2±3.7	12/75	30/233	NR	NR	21/75	93/233	12/75	35/233	NR	NR
Park 2016^Citation34	8.0±3.7	7.6±1.9	7/50	19/102	10/50	18/102	28/50	70/102	NR	NR	0.7±1.4	0.6±1.2
Xiang 2016^Citation35	7.7±4.2	12.4±7.9	26/49	37/47	NR	NR	3/49	8/47	20/49	40/47	NR	NR
Ren 2017^Citation36	<10	<10	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR
Overall	6.4±3.2	6.7±3.7	55/317	102/582	10/81	18/138	71/547	325/1,472	113/516	431/1,376	0.9±1.8	0.7±1.3

Abbreviations: ET, endoscopic thyroidectomy; LN, lymph node; NR, not reported; OT, open thyroidectomy.

Figure 2 Forest plot and meta-analysis of (A) operative time; (B) number of retrieved lymph nodes; (C) blood loss.

Abbreviations: ET, endoscopic thyroidectomy; OT, open thyroidectomy.

Table 3 Outcomes of meta-analysis comparing ET vs OT

Outcomes	No of studies	No of patients		OR/WMD	95% CI	P-value	I^2 (%)
		ET	OT
Intraoperative outcomes
Operative time	11	724	1,640	50.46	40.50, 60.42	<0.00001	87
No of retrieved LNs	10	676	1,640	−0.53	−1.29, 0.22	0.17	80
Blood loss	4	179	290	4.37	−2.62, 11.36	0.22	72
Postoperative outcomes
Duration of drainage	3	104	167	1.88	1.22, 2.54	<0.00001	76
Volume of drainage	5	230	341	111.96	61.66, 162.26	<0.0001	95
Hospitalization period	8	566	1,440	0.65	0.06, 1.24	0.03	90
Transient RLN palsy	11	762	1,832	2.64	1.36, 5.11	0.004	48
Permanent RLN palsy	9	653	1,679	2.04	0.80, 5.23	0.14	0
Transient hypocalcemia	8	555	1,416	0.93	0.46, 1.87	0.84	81
Permanent hypocalcemia	7	521	1,386	0.82	0.39, 1.69	0.58	0
Hematoma or bleeding	10	674	1,538	1.76	0.81, 3.81	0.15	0
Seroma	4	258	357	1.33	0.53, 3.34	0.54	0
Oncological outcomes
sTg <1.0 ng/mL	2	29	343	0.33	0.13, 0.81	0.02	0
Tumor recurrences	6	398	1,170	0.54	0.22, 1.32	0.18	0

Abbreviations: ET, endoscopic thyroidectomy; LN, lymph node; OT, open thyroidectomy; RLN, recurrent laryngeal nerve; sTg, stimulated thyroglobulin; WMD, weighted mean difference.

Figure 3 Forest plot and meta-analysis of (A) duration of drainage; (B) volume of drainage; (C) hospitalization period.

Abbreviations: ET, endoscopic thyroidectomy; OT, open thyroidectomy.

Figure 4 Forest plot and meta-analysis of (A) transient RLN palsy; (B) permanent RLN palsy; (C) transient hypocalcemia; (D) permanent hypocalcemia; (E) hematoma or bleeding; (F) seroma.

Abbreviations: ET, endoscopic thyroidectomy; M–H, Mantel–Haenszel; OT, open thyroidectomy; RLN, recurrent laryngeal nerve.

Figure 5 Forest plot and meta-analysis of (A) number of sTg <1 ng/mL; (B) number of tumor recurrences.

Abbreviations: ET, endoscopic thyroidectomy; M–H, Mantel–Haenszel; OT, open thyroidectomy; sTg, stimulated thyroglobulin.

Table 4 Meta-analysis of the subgroups according to the extent of thyroidectomy

Outcomes	No of studies	No of patients		OR/WMD	95% CI	P-value	I^2 (%)
		ET	OT
TT
Operative time	4	269	410	47.40	34.18, 60.61	<0.00001	84
No of retrieved LNs	4	269	410	−0.10	−0.50, 0.30	0.63	0
Blood loss	2	125	225	2.35	−7.27, 11.97	0.63	79
Volume of drainage	2	145	240	100.31	−33.67, 234.29	0.14	94
Hospitalization period	2	145	240	0.33	0.10, 0.56	0.005	0
Transient RLN palsy	4	269	410	1.58	0.66, 3.79	0.31	0
Permanent RLN palsy	3	194	287	1.89	0.49, 7.33	0.36	20
Transient hypocalcemia	3	194	287	1.48	0.68, 3.20	0.32	70
Permanent hypocalcemia	3	194	287	1.35	0.46, 3.99	0.58	0
Hematoma or bleeding	3	219	308	2.93	0.61, 14.02	0.18	0
Seroma	2	170	261	0.67	0.10, 4.55	0.68	0
LTT
Operative time	4	148	166	45.96	29.33, 62.59	<0.00001	90
No of retrieved  LNs	4	203	364	−0.89	−2.48, 0.70	0.27	90
Blood loss	2	54	65	6.52	−0.72, 13.76	0.08	46
Duration of drainage	2	54	65	2.20	1.82, 2.59	<0.00001	0
Volume of drainage	2	54	65	114.99	99.74, 130.24	<0.00001	0
Hospitalization period	3	114	136	0.81	−0.19, 1.82	0.11	95
Transient RLN palsy	4	186	358	2.83	1.26, 6.36	0.01	44
Permanent RLN palsy	3	152	328	5.29	0.54, 52.22	0.15	0
Transient hypocalcemia	2	54	65	0.31	0.07, 1.36	0.12	0
Hematoma or bleeding	4	148	166	2.20	0.62, 7.84	0.22	0

Abbreviations: ET, endoscopic thyroidectomy; LN, lymph node; LTT, less than total thyroidectomy; OT, open thyroidectomy; RLN, recurrent laryngeal nerve; TT, total thyroidectomy; WMD, weighted mean difference.

Table 5 Pooled surgical outcomes between ET and OT groups from all eligible studies

Outcomes	ET	OT	References
Intraoperative outcomes
Operative time (minutes)	142.0±45.9	92.3±36.6	7, 27–31, 34–36
No of retrieved LNs	4.3±4.1	4.7±4.0	7, 27–31, 33–35
Blood loss (mL)	19.6±24.5	14.5±9.8	7, 31, 34, 36
Postoperative outcomes
Duration of drainage (days)	5.9±1.9	4.6±2.0	31, 34, 36
Volume of drainage (mL)	202.3±142.0	112.7±56.9	28, 29, 31, 34, 36
Hospitalization period (days)	5.3±2.5	4.8±2.9	27–30, 34, 36
Transient RLN palsy, n (%)	64 (8.3)	60 (3.3)	7, 26–29, 31–36
Permanent RLN palsy, n (%)	7 (1.1)	8 (0.5)	26–29, 32–36
Transient hypocalcemia, n (%)	116 (20.9)	366 (25.8)	26, 28, 29, 31, 32, 34–36
Permanent hypocalcemia, n (%)	10 (1.9)	31 (2.2)	26, 28, 29, 32, 34–36
Hematoma or bleeding, n (%)	13 (1.9)	17 (1.1)	7, 26–32, 35, 36
Seroma, n (%)	10 (3.9)	9 (2.5)	7, 27–29
Oncological outcomes
sTg <1.0 ng/mL, n (%)	9 (31.0)	176 (51.3)	26, 32
Tumor recurrences, n (%)	6 (1.5)	31 (2.6)	26, 29–32, 36

Abbreviations: ET, endoscopic thyroidectomy; LN, lymph node; OT, open thyroidectomy; RLN, recurrent laryngeal nerve; sTg, stimulated thyroglobulin.

Figure 6 Funnel plot of transient recurrent laryngeal nerve palsy in all included studies.

ChungYSChoeJHKangKHEndoscopic thyroidectomy for thyroid malignancies: comparison with conventional open thyroidec-tomyWorld J Surg200731122302230617566819

 PubMed Web of Science ®Google Scholar

HongHJKimWSKohYWEndoscopic thyroidectomy via an axillo-breast approach without gas insufflation for benign thyroid nodules and micropapillary carcinomas: preliminary resultsYonsei Med J201152464365421623608

 PubMed Web of Science ®Google Scholar

KimWWKimJSHurSMIs robotic surgery superior to endoscopic and open surgeries in thyroid cancer?World J Surg201135477978421253726

 PubMed Web of Science ®Google Scholar

TaeKJiYBChoSHKimKRKimDWKimDSInitial experience with a gasless unilateral axillo-breast or axillary approach endoscopic thyroidectomy for papillary thyroid microcarcinoma: comparison with conventional open thyroidectomySurg Laparosc Endosc Percutan Tech201121316216921654299

 PubMed Web of Science ®Google Scholar

LeeHLeeJSungKYComparative study comparing endoscopic thyroidectomy using the axillary approach and open thyroidectomy for papillary thyroid microcarcinomaWorld J Surg Oncol20121026923234462

 PubMed Web of Science ®Google Scholar

TanZGuJHanQComparison of conventional open thyroidec-tomy and endoscopic thyroidectomy via breast approach for papillary thyroid carcinomaInt J Endocrinol2015201515

 Web of Science ®Google Scholar

HuangJKMaLSongWHLuBYHuangYBDongHMQuality of life and cosmetic result of single-port access endoscopic thyroidectomy via axillary approach in patients with papillary thyroid carcinomaOnco Targets Ther201694053405927445496

 PubMed Web of Science ®Google Scholar

KimSKKangSYYounHJJungSHComparison of conventional thyroidectomy and endoscopic thyroidectomy via axillo-bilateral breast approach in papillary thyroid carcinoma patientsSurg Endosc20163083419342526511120

 PubMed Web of Science ®Google Scholar

LeeMCParkHLeeBCLeeGHChoiIJComparison of quality of life between open and endoscopic thyroidectomy for papillary thyroid cancerHead Neck201638E827E83125917054

 PubMed Web of Science ®Google Scholar

ParkKNJungCHMokJOKwakJJLeeSWProspective comparative study of endoscopic via unilateral axillobreast approach versus open conventional total thyroidectomy in patients with papillary thyroid carcinomaSurg Endosc20163093797380126659230

 PubMed Web of Science ®Google Scholar

XiangDXieLLiZWangPYeMZhuMEndoscopic thyroidectomy along with bilateral central neck dissection (ETBC) increases the risk of transient hypoparathyroidism for patients with thyroid carcinomaEndocrine201653374775326886901

 PubMed Web of Science ®Google Scholar

RenXDaiZShaHWuJHongXXiuZComparative study of endoscopic thyroidectomy via a breast approach versus conventional open thyroidectomy in papillary thyroid microcarcinoma patientsBiomedical Research2017281253155320

 Google Scholar