A Comparative Analysis of Hypocalcemia Incidence in Patients Undergoing Thyroidectomy: Ligasure vs Conventional Ligation of Vessels by Knot Tying
Phase: NA
Conditions: Hypocalcemia After Total Thyroidectomy, Hypocalcemia
Sponsor: Gulab Devi Hospital

 
 
 
 
 
Dated: 1/03/2024  
 
 
Study Protocol/Synopsis 
 
 
A Comparative Analysis of Hypocalcemia Incidence in Patients Undergoing Thyroidectomy: 
Ligasure vs Conventional Ligation of vessels by knot tying.  
 
 
 
NCT Number: NCT06716632 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

A Comparative Analysis of Hypocalcemia Incidence in Patients Undergoing Thyroidectomy: 
Ligasure vs Conventional Ligation of vessels by knot tying. 
 
Introduction: 
Thyroidectomy is surgical removal of all or part of the thyroid gland, which is located in the 
front of the neck. Depending on how much thyroid tissue is removed, thyroidectomy could 
be classified into Total thyroidectomy, subtotal thyroidectomy, near total thyroidectomy and 
lobectomy. 
In total thyroidectomy, the entire thyroid gland is removed. In thyroid lobectomy, one lobe of 
the thyroid gland is removed. In Thyroid lobectomy with isthmectomy, thyroid lobe along 
with the isthmus is removed. In Subtotal thyroidectomy, a small portion of the thyroid gland 
is left during the surgery. This portion is near the trachea, parathyroid glands and the 
recurrent laryngeal nerve. Indications for thyroidectomy are thyroid cancer, MNG, solitary 
thyroid nodule.  
Complications of thyroidectomy include hoarseness or change in voice (33.3%), damage to 
parathyroid glands causing hypocalcaemia (54.4%), wound infection (3.4%), dysphagia 
(32.8%). Several risk factors may contribute to the occurrence of post-thyroidectomy 
complications, including age, gender, enlarged gland size, type of thyroid disease, presence 
of fibrosis and inflammation, extent of thyroidectomy, and lymph node dissection. Among 
these complications, hypocalcaemia and recurrent laryngeal nerve injury are the most 
frequently observed1,2. 
The superior and inferior parathyroid glands, located near the thyroid gland, play a vital role 
in calcium homeostasis by producing parathyroid hormone (PTH), which regulates calcium 
levels in the bloodstream.  
Hypocalcemia, characterized by low serum calcium levels. It is a frequent and significant 
complication of thyroidectomy due to damage, ischemia, or removal of one or more of the 
parathyroid glands during surgery. It can be categorized into two main types, transient 
hypocalcemia and permanent hypocalcemia. The primary difference between these two 
types lies in the duration. Transient hypocalcemia lasts for 3 months after surgery, while 
permanent hypocalcemia persists for 3 months or longer after surgery3.  
To minimize the risk of parathyroid gland damage, various surgical techniques have been 
developed, including the utilization of energy-based devices such as Ligasure. Ligasure has 
gained popularity in thyroidectomy procedures due to its potential advantages in terms of 
precision, hemostasis, and reduced operative time.  
Ligasure is a bipolar vascular sealing system utilized to achieve effective control of bleeding 
and create a bloodless surgical environment. It operates by utilizing an electrical current 
within the frequency range of 2-4 MHz It induces denaturation of collagen and elastin within 
the vessels and surrounding tissues. The localized tissue temperatures typically range 
between 60-100°C, facilitating the fusion of collagen and elastin in the vessel walls. This 
fusion process creates a durable sealed zone without any carbonization and enables 
hemostasis in vessels with diameters of up to 7 mm4,5. 
Conventional methods of vessel ligation, which involve the use of ties and suture ligatures, 
have long been employed in most medical centers. While these techniques effectively control 
bleeding from vessels, they are time-consuming and carry the risk of harming adjacent 
structures like the recurrent and superior laryngeal nerves. In light of the growing demand 
for time-saving procedures, particularly in high-volume operating theaters where efficient 
patient turnover is essential, there is a growing interest in devices or techniques that 
minimize the reliance on conventional knot-tying or suture ligation for achieving hemostasis. 
This is particularly important to optimize anesthesia time and improve overall efficiency6. 

According to a recent study, hypocalcemia occurred in 6.7% of individuals who underwent 
surgery using the Liga Sure method7. In a separate study, 32.4% of patients who had surgery 
utilizing the traditional knot tying technique experienced hypocalcemia8.  
However, despite the increasing use of Ligasure and other energy devices, there is a paucity 
of research comparing their efficacy in preventing hypocalcemia after thyroidectomy. 
Therefore, this study aims to address the existing gap in knowledge by conducting a 
comprehensive comparison of the incidence of hypocalcemia in patients undergoing 
thyroidectomy using Ligasure versus the conventional artery forceps/knot tying technique. 
Objective:  
This study aims to address the existing gap in knowledge by conducting a comprehensive 
comparison of the incidence of hypocalcemia in patients undergoing thyroidectomy using 
Ligasure versus conventional ligation of vessels by knot tying. Additionally, secondary 
outcomes such as operative time, intraoperative bleeding, length of hospital stay, and 
postoperative complications will be assessed to provide a holistic understanding of the two 
surgical approaches. 
Hypothesis:  
The incidence of hypocalcemia in patients undergoing thyroidectomy using Ligasure is less 
versus conventional ligation of vessels by knot tying. 
Operational definition: 
1)Hypocalcemia: Patients having calcium level below 8.0 mg/dL will be labelled as 
hypocalcemia. 
Material and methods: 
1)Study design: 
Randomized control trial 
2)Study setting: 
Surgical unit I Gulab Devi hospital, Lahore 
3)Duration of study: 
6 months after approval of study. 
4)Sample size: 
Sample size will be 76 patients (38 in each group) calculated by WHO calculator, with confidence 
interval of 95% and margin of error 5%, power of test at 90% taking 6.7 % in Liga Sure7 vs 32.4% in 
conventional knot tying technique8.  
5)Sampling technique: 
Non-probability purposive sampling for including patients in study and random allocation for 
grouping of patients using lottery method. 
6)Sample Selection:  
Inclusion criteria: 
1) Patients from both genders.  
2) Age between 20 years to 50 years. 
3) Patients undergoing Total thyroidectomy for benign thyroid disease. 
Exclusion criteria: 
1) Patients having pre-operative hypocalcaemia. 
2) Patients having malignant thyroid disease. 
3)Patients having recurrent thyroid disease. 
4)Patients having lobectomy + isthmectomy. 
5)Patients having pro-operative calcium supplements. 
Data collection procedure: 
After approval from hospital ethical committee,76 patients (38 in each case) will be enrolled 
presenting in department of Surgery, Gulab Devi Hospital, Lahore for total thyroidectomy. 
Informed consent will be taken from each patient. Demographic information including age 
and address will be noted. Patients will be divided into two groups by using lottery method. 

Group A will be managed with Ligasure and group B will be managed with conventional 
ligation of vessels by knot tying. All the patients will be subjected to their treatment 
according to their respective groups by single experienced surgeon having minimum 
experience of five years. Calcium levels will be taken pre operatively, 24 and 48 hours 
postoperatively. All the data will be collected in a pre-designed proforma. All information 
regarding patients will be kept confidential and bias will be addressed by single blind data 
collection procedure. 
Data Analysis: 
Statistical analysis will be done using Statistical Package for Social Sciences (SPSS) version 24. 
Mean and standard deviation was calculated for all quantitative variables like age, BMI, 
serum calcium level. Qualitative data like gender, presence of hypocalcemia will be presented 
as frequencies and percentages. Chi square test will be applied to compare two treatments 
effectiveness by taking P value 0.05 as significant. 
References: 
1. Algahtani SM, Alatawi AS, Alalawi YS, Alatawi AS, Alalawi Y. Post-thyroidectomy 
hypocalcemia: a single-center experience. Cures. 2021;13(11). 
 
2. Chahardahmasumi E, Salehidoost R, Amini M, Aminorroaya A, Rezvanian H, Kachooei A, Iraj 
B, Nazem M, Kolahdoozan M. Assessment of the early and late complication after 
thyroidectomy. Advanced biomedical research. 2019;8. 
 
3. Eismontas V, Slepavicius A, Janusonis V, Zeromskas P, Beisa V, Strupas K, et al. Predictors of 
postoperative hypocalcemia occurring after a total thyroidectomy: results of prospective 
multicenter study. BMC surgery. 2018;18(1):1-12. 
 
4. Mishra V. Comparative study between harmonic scalpel and ligasure vessel sealing system: 
in open and laparoscopic surgery. World J Laparosc Surg. 2013;6(2):74-6. 
 
5. Arowolo OA, Olasehinde 0, Adisa AO, Adeyemo A, Alatise Ol, Wuraola F. Early experience 
with ligasure thyroidectomy in a Nigeria Teaching Hospital. Nigerian Journal of Surgery. 
2019;25(1):64-9. 
 
6. Hassan MF, Mahdi QA. Use of Bipolar Vessel Sealing Device (Ligasure) Versus Conventional 
Suture Ligation in Thyroid Surgery. IRAQI POSTGRADUATE MEDICAL JOURNAL. 2021;20(2). 
 
7. Ahmed H. Khafagy a, Ibrahim Abdelnaby. Total thyroidectomy: Ligasure versus Clamp & 
Knot technique for intraoperative hemostasis. Egyptian Journal of Ear, Nose, Throat and 
Allied Sciences (2013) 14, 59–65. 
 
8. Feng-Yu Chiang, Kang Dae Lee, Kyung Tae, Ralph P Tufano, Che-Wei Wu, I-Cheng Lu, Pi-Ying 
Chang, Yi-Chu Lin, Tzu-Yen Huang. Comparison of hypocalcemia rates between LigaSure and 
clamp-and-tie hemostatic technique in total thyroidectomies. Head Neck. 2019 
Oct;41(10):3677-3683. doi: 10.1002/hed.25884. Epub 2019 Jul 26. 
 
 
 
 
 
 
 
 

Questionnaire 
 
1)Demographic Information: 
a. Name: ________________  
b. Age: ___________ years 
c. Gender: Male / Female 
d. Address: _______________ 
e. Occupation: ____________ 
 
2)Pre-operative diagnosis: _________________ 
 
3)Type of surgery: 
a. Total thyroidectomy  
 
 
4)Surgery done by: 
a. Professor 
 
b. Associate Professor 
 
c. Assistant Professor 
 
d. Senior Registrar 
 
 
5)Symptoms of hypocalcaemia: 
                                                                   Pre-operatively                                  Post operatively 
a. Tingling:                                                
  Yes    
  No                                   
  Yes  
  No                                    
b. Muscle spasms:                                   
  Yes    
  No                                   
  Yes  
  No                                    
c. Seizures:                                                
  Yes    
  No                                   
  Yes  
  No                                    
d. Paraesthesia/Numbness:                   
  Yes    
  No                                   
   Yes 
  No                                     
e. Laryngospasm:                                     
  Yes   
  No                                    
  Yes  
  No                                    
f.  Tetany:                                                   
  Yes   
  No                                    
  Yes  
  No                                                        
g. Chvostek’s sign:                                    
  Yes   
  No                                    
  Yes  
  No                                    
h. Trousseau’s sign:                                  
  Yes   
  No                                    
  Yes  
  No                                    
 
6)Treatment Allocation: 
a. Group A: Ligasure 
b. Group B: Conventional ligation technique 
 
7)Surgical Outcomes: 
a. Operative Time: ___________ minutes 
b. Intraoperative Bleeding (Estimated amounts_ _________________ 
c. per-operative parathyroid identified: 
 Yes      
 No    How many: ___________ 
d. Length of Hospital Stay: ___________ days 
e. Postoperative Complications: None / Infection / Hoarseness / Other (Please specify: ___________) 
f. Drain output :1st day________,2nd day_________,3rd day_________. 
 
8)Hypocalcaemia Assessment: 
a. Preoperative Calcium Level: ___________ mg/dL 
b. Calcium Level at 24 Hours Postoperatively: ___________ mg/dL 
c. Calcium Level at 48 Hours Postoperatively: ___________ mg/dL 
 
9)Histology of Specimen: _______________________ 
 
 
10)Hypocalcaemia Management: 
a. Injection Ca gluconate  
 
b. Tab Qalsan D  
 
c. Tab one Alpha  
 
d. Others