Effectiveness and Safety of Single-port Versus Multi-port Laparoscopic Surgery in the Treatment of Ectopic Pregnancy
Phase: NA
Conditions: Ectopic Pregnancy
Sponsor: Hung Vuong Hospital

 
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STUDY PROTOCOL AND STATISTICAL ANALYSIS PLAN 
Effectiveness and Safety of Single-port Versus Multi-port Laparoscopic Surgery in 
the Treatment of Ectopic Pregnancy 
 
Principle investigator 
 
Tri Bao Nguyen, MD 
 
 
 
 
 
Obstetrician – Gynecologist 
 
 
 
 
 
Hung Vuong hospital  
 
 
 
 
 
Ho Chi Minh city, Vietnam 
 
Protocol identification number  
5863/QĐ-BVHV (dated April, 2023) 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
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Table of contents  
 
1. Introduction ……………………………………………………………………… 3 
2. Study design ……………………………………………………………………... 3-5 
3. Aims and objectives ……………………………………………………………... 5 
4. Outcomes …….………………………………………………………………….. 5 
5. Populations and subgroups to be analyzed …………………………………........ 6 
6. Analyses …………………………………………………………………………. 6 
7. References ……………………………………………………………………….. 6 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
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1. Introduction 
Single-port laparoscopic surgery has become one of the treatment options for ectopic 
pregnancy with certain advantages such as reduced numbers of incision and scars, fast 
recovery, and increased patient’s satisfaction post-surgery. Although several research 
groups have investigated the differences between single-port and traditional multi-port 
laparoscopic surgery, the investigators have not had such studies carried out at Hung 
Vuong hospital. Therefore, the investigators set out this project to compare the 
effectiveness and safety of single-port versus conventional multi-port laparoscopic surgery 
in the treatment of ectopic pregnancy at Hung Vuong hospital, aiming to gain insights into 
the application potential of this technique to the gynecologic laparoscopy procedures. 
2. Study design  
Study subjects will be recruited from November 2023 to May 2024 at Hung Vuong 
hospital, Ho Chi Minh city, Vietnam. Inclusion criteria for participants in this 
study include pregnant women who are 18 years old or older; who are indicated for 
laparoscopic surgery to treat ectopic pregnancy; and who agree to participate and provide 
a 
consent. 
Exclusion 
criteria include pregnant 
women 
who are 
allergic 
to 
anesthesia; who have hemodynamic instability; or who have ruptured ectopic pregnancies.  
The study is a parallel-group randomized control trial with 2 arms and no blinding. Arm 1 
includes patients who will undergo single-port laparoscopy while aim 2 have patients 
undergo multi-port laparoscopy. All patients are randomized using computer-generated 
sequences with allocation ratio 1:1. Primary outcomes include blood loss, and surgical 
time. Secondary outcomes include pain intensity, surgical complications, hospital stay, and 
pneumoperitoneum. Blood loss and surgical time will be measured right after surgery while 
other outcomes will be measured during hospital stay. Technically, the investigators will 
perform examination 3-4 days post-surgery. Sampling will be stopped and the study will 
be concluded when patients are discharged from the hospital. The study design is visualized 
in Figure 1 below. 
 
 
 
 
 
 
 
 

 
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Figure 1: The CONSORT flow diagram of the study  
 
 
 
 
 
 
 
 
 
 

 
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Sample size calculation  
The sample size is calculated based on the following formula: 
𝑛=
(𝑧1−𝛼
2 +  𝑧1−𝛽)2[𝜎1
2 + 𝜎2
2
𝑟]
∆2
 
 
𝑟= 𝑛1
𝑛2
 
 
∆= 𝜇1 −𝜇2 
 
Where: 
n: required minimum sample size in each group 
µ: outcome in each group  
σ: standard deviation in each group  
z: z score  
α: type I error, α = 0,05  
β: type II error, β = 0,15 (statistical power = 0,85)  
 
Based on Hsu-Dong Sun’s group [1], sample sizes for each variable are as follows 
 
 
 
 
 
 
 
 
 
 
The investigators anticipate to obtain the sample size of 50 for each group. 
 
3. Aims and objectives 
The aim is to compare the effectiveness and safety of single-port versus traditional multi-
port laparoscopic surgery in the treatment of ectopic pregnancy. Specifically, the surgical 
effectiveness will be evaluated via beta-hCG values, ultrasound imaging, and rate of 
switching to open surgery. The surgical safety will be evaluated via surgical time, blood 
loss, pain intensity, and surgical complications. 
Variables 
4-port 
1-port 
Sample size
Bowel recovery time 
6,2 ± 1 
7,2 ± 1,4 
24 
Blood loss 
125 ± 156,9 
335 ± 104 
50 
Visual analogue scale 
3 ± 0,5 
3,6 ± 0,6 
14 

 
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4. Outcomes  
The primary outcomes of interest are the amount of blood loss during surgery, and surgical 
time. Secondary outcomes include pain intensity as indicated by visual analogue scale, 
surgical complications such as organ damages and surgical site infections, hospital stay, 
and pneumoperitoneum. The primary outcomes will be evaluated immediately post-
surgery while the secondary outcomes will be evaluated within 4 weeks post-surgery by 
qualified practitioners. 
 
5. Populations and subgroups to be analyzed 
Populations: intention-to-treat 
Subgroups: single-port versus multi-port group. These 2 subgroups will be analyzed using 
intention-to-treat populations.  
 
6. Analyses  
Data will be analyzed using Stata 16 (StataCorp LLC, College Station, TX). Normally 
distributed data will be expressed as mean ± standard deviation, while non-normally 
distributed data will be shown as medians with interquartile ranges. T-test for normally 
distributed continuous variables and Mann-Whitney-U test for non-normally distributed 
continuous variables will be used to compare between groups. Categorical variables will 
be reported as absolute numbers and percentages; the Chi-square test or Fisher's exact test 
will be utilized for comparison A p-value of <0.05 will be considered statistically 
significant.  
 
7.    References 
[1] Sun, Hsu-Dong, et al. "Comparison of single-port and three-port laparoscopic 
salpingectomy in the management for tubal pregnancy." Journal of the Chinese Medical 
Association 81.5 (2018): 469-474.