Repair failure and associated factors among women who underwent obstetric fistula surgery in Southwest Ethiopia: A retrospective study

Abstract

Background:

Surgical repair is one of the management strategies for obstetric fistulae, which are associated with tragic obstetric morbidities.

Objective:

This study assessed the proportion of repair failures and associated factors among women who underwent obstetric fistula surgery at the Mettu Hamlin Fistula Center.

Design:

This study is an institution-based, retrospective, cross-sectional design.

Methods:

This study included 385 patients who underwent obstetric fistula repair surgery at the Mettu Hamlin Fistula Center between 2015 and 2020. Participants were selected using a simple random sampling technique. EpiData version 3.1 and STATA version 14.2 were used for data entry and analysis, respectively. The association between obstetric fistula failure and independent variables was tested using binary logistic regression analysis. In the bivariable analysis, a p-value of less than 0.25 was used as a cut-off point to include variables in the multivariable logistic regression analysis. The statistical significance was finally set at a p-value of less than 0.05.

Results:

Of the 385 participants who underwent obstetric fistula surgical repair, about 18.2% (95% confidence interval = 14.6–22.3) failed to close. Larger fistula size (>3 cm) (adjusted odds ratio (AOR) = 4.6; 95% confidence interval = 2.34–8.91), urethral damage (adjusted odds ratio = 2.8; 95% confidence interval = 1.47–5.44), home delivery (adjusted odds ratio = 5; 95% confidence interval = 2.56–9.77), and malnutrition (body mass index <18.5 kg/m²) (adjusted odds ratio = 2.7; 95% confidence interval = 1.10–6.79) were variables significantly associated with obstetric fistula repair failure.

Conclusion:

Obstetric fistula repair failure was lower in the area compared to the majority, but not all, of previous findings. Home delivery, damaged urethra, larger fistula size, and lower body mass index increased the probability of repair failure. To prevent repair failure early, it is necessary to strengthen pre- and post-operative care, including the assessment of women’s nutritional status, fistula size, and urethral injury. Moreover, maternal care providers should educate mothers about the negative outcomes of home deliveries.

Introduction

An obstetric fistula (OF) is an injury to the birth canal and adjacent tissues during childbirth. It is a tragic condition that results from persistent fetal pressure on the maternal birth canal during prolonged or obstructed labor. ¹ According to the World Health Organization (WHO), obstetric fistulas affect 50,000–100,000 women annually worldwide. ² It frequently occurs in areas of low economic standing and limited access to obstetric care, such as the Sub-Saharan Africa and South Asian regions. For instance, it affects 1.6 and 1.2 per 1000 women of reproductive age in Sub-Saharan Africa and Southern Asia, respectively. ³ Of the 7590 deliveries conducted in the last 5 years in Ethiopia, approximately 32 (0.42%) developed obstetric fistulas. ⁴

OF is an obstetric morbidity that hurts the overall health of the survivor. Thus, women with OF may suffer from physical, psychological, economic, and social problems. ⁵ Fortunately, obstetric fistulae are almost always preventable. ⁶ Important prevention strategies include adequate nutrition for women of reproductive age, avoiding premature marriage and pregnancy, preventing harmful traditional practices (HTPs), and having early access to emergency obstetric care services. ⁷ Surgical repair is a common treatment option for incontinence in women who develop fistulas. The effectiveness of the procedure depends on the size of the bladder or rectal defect. Incontinence may not improve in all patients who undergo surgical repair. Even if the surgeon is masterful, approximately 25%–35% of repaired cases can fail. ⁸ In addition, the degree of scarring and urethral involvement may affect the outcome of the repair.^9,10 Studies showed OF repair failure rates of 14.4% and 30% in Western China ¹¹ and Liberia, ¹² respectively. In Ethiopia, a higher proportion of OF failures was seen in the Bahir Dar Hamlin Fistula Center (35.3%), ¹³ followed by the Yirgalem Hamlin Fistula Center (28.8%). ¹⁴ A low proportion of repair failures was observed in Addis Ababa, the capital city of Ethiopia (11%). ¹⁵

OF repair failure is related to certain risk factors, including severe vaginal scarring, urethral destruction, bladder size, and circumferential involvement.^15,16 Evidence shows that most attributes of OF repair failure are confined to the characteristics of the fistula rather than that of the patient.^9,16 For instance, it is associated with the fistula size,^{11,13,14,17,18} duration of bladder catheterization,^14,17 duration of labor,^13,14,19 repair site, ¹⁷ previous repair attempts,^{12,17 –19} type of fistula, ¹⁴ post-operation infection, ¹³ duration of fistula, ¹⁹ and bladder destruction. ¹³

OF repair procedures have been conducted for centuries; ²⁰ however, little attention has been paid globally. Evaluation of surgical repair outcomes is important for determining further management options and preventing complications related to incontinence and psychological trauma. Although the Federal Ministry of Health (FMOH) of Ethiopia plans to completely eliminate fistulas and escalate the rehabilitation of OF survivors by 2025, ²¹ little is known about the proportion of OF repair failure in Ethiopia, particularly in the southwestern region. Hence, this study aimed to estimate the proportion of repair failures and the associated factors among women who underwent obstetric fistula surgery at the Mettu Hamlin Fistula Center.

Methods and materials

Study design, period, and setting

This institution-based retrospective study was reported based on the “Strengthening the Reporting of Observational Studies in Epidemiology (StroBE) statement: Guidelines for Reporting Observational Studies.” ²² This study was conducted using the records of patients treated between 2015 and 2020 at the Mettu Hamlin Fistula Center. It is located approximately 600 km away from Addis Ababa. This center, established in 2010, was the only fistula center located in the southwestern part of the country among the five national fistula centers that provide services to people from the Western Oromia Region, the Southwest Regional State, and the Gambella Regional State.

Participants and eligibility criteria

All women who underwent OF repair between 2015 and 2020 at the Mettu Hamlin Fistula Center were included in this study. The records of all selected patients who underwent OF treatment at the Mettu Hamlin Fistula Center and those with complete information were extracted.

Sample size and sampling procedure

A single population proportion formula was used to calculate the sample size, assuming a 95% confidence interval (CI) and a 35.5% proportion of OF failure. ¹³ Considering a 10% non-response rate, 385 participants were taken as the final sample size for this study. A sampling frame was created for patients who received treatment at the Mettu Hamlin Fistula Center between 2015 and 2020 using a unique registration number. Finally, participants were selected using a simple random sampling technique.

Data collection tool and collection process

After reviewing the relevant literature, a tool adapted from the national fistula patient management recording format was used to collect data. Data were collected from patient cards, operative notes, and discharge logbooks between January 2015 and January 2020. The data extraction tool included information regarding the sociodemographic factors, pre- and post-operative care factors, nutritional factors, and obstetric characteristics of the patients. Data were collected by three healthcare professionals with BSc degrees and experience in data collection. The data collectors received 2 days of training on data extraction techniques. A midwife with a BSc and researchers oversaw the overall data collection process on a daily basis.

Study variables

The dependent variable was obstetric fistula repair failure. Independent variables included socio-demographics (age, age at first marriage, educational status, and residence), obstetrics (antenatal care (ANC) utilization, parity, place of delivery, mode of delivery, and duration of labor), pre- and post-operative care (antibiotic use and duration of bladder catheterization), and nutrition (body mass index (BMI) and weight).

Operational definitions

• Obstetric fistula repair failure: it refers to failed repair and/or incontinence after successful OF repair surgery after 21 days of surgery. ²³

• Fistula classification: it depends on the distance of the distal edge of the fistula from the external urethral meatus or the hymen (type 1 fistula is greater than 3.5 cm; type 2 fistula is between 2.5 and 3.5 cm; type 3 fistula is between 1.5 and 2.5 cm; and type 4 fistula is less than 1.5 cm from the external urethral meatus or hymen), size (less than 1.5 cm; 1.5–3 cm; and greater than 3 cm in the largest diameter), and the extent of the scarring (none or only mild fibrosis; moderate or severe fibrosis; and special consideration). ¹⁰

• Circumferential defect: this refers to fistula-induced detachment of the urethra from the bladder. ²⁴

Data quality control

The study tool was pre-tested on 20 (5%) records of patients who underwent OF surgery in 2021 at the Mettu Hamlin Fistula Center. It was then evaluated for clarity, instrument adequacy, and time required to complete it and modified accordingly. The data collectors and supervisors received 2 days of training before data collection. The researchers and supervisors double-checked the gathered data each day. Data cleaning was performed to ensure completeness, consistency, and extreme values.

Statistical analysis

EpiData version 3.1 and STATA version 14.2 were used for data entry analysis, respectively. Univariate analysis was performed based on frequency and percentage, and the results are presented as narratives, tables, and graphs. The rate of failure of OF repair was also calculated. The association between independent variables and OF repair failure was tested using binary logistic regression analysis. Variables that yielded p-values of less than 0.25 in the bivariate analysis were considered candidates for multivariable logistic regression analysis. Multicollinearity between the independent variables included in the model was checked using the variance inflation factor (VIF). The absence of multicollinearity between variables was confirmed at a VIF value of less than 10. The Hosmer–Lemeshow test was used to select the best-fitting model. Multivariable outputs were presented as adjusted odds ratios (AORs). Statistical significance was set at p < 0.05.

Results

Socio-demographic characteristics of participants

A total of 385 patient records were reviewed. Most of the patients, 299 (77.7%), were rural residents. Regarding educational status, 274 (71.2%) women had a formal education. The average age of the participants was 30 years, with a standard deviation (SD) of ±5.7. Moreover, 118 (30.6%) women were married before the age of 18 years (Table 1).

Table 1.

Socio-demographic characteristic of women who had obstetric fistula surgery at Mettu Hamlin Fistula Center, Southwestern Ethiopia (n = 385).

Variable	Category	Frequency	Percent
Age at marriage	<18 years	118	30.6
	>18 years	267	69.4
Residence	Urban	86	22.3
	Rural	299	77.7
Age during repair in years	<20 years	6	1.6
	20–34 years	258	67
	⩾34 years	121	31.4
Educational status	Have formal education	111	28.8
	Do not have formal education	274	71.2

Obstetric characteristics of participants

Two hundred ninety-eight (77.4%) participants gave birth at a health institution. Most women (264 (68.6%)) did not receive ANC. Regarding the duration of labor, about 280 (72.7%) women were in labor for more than 2 days, while 105 (27.3%) were in labor for less than 2 days. More than half the participants, 200 (52%) were multiparous. Approximately 211 (54.4%) women delivered via spontaneous vaginal delivery (Table 2).

Table 2.

Obstetric characteristics of women who had obstetric fistula surgery at Mettu Hamlin Fistula Center, Southwestern Ethiopia (n = 385).

Variable	Category	Frequency	Percent
Place of delivery	Home	87	22.6
	Health institution	298	77.4
Antenatal care utilization	Yes	121	31.4
	No	264	68.6
Duration of the labor	⩽2 days	105	27.3
	Greater than 2 days	280	72.7
Parity	Primiparous	185	48
	Multiparous	200	52
Modes of delivery	Spontaneous vaginal	211	54.8
	Instrumental or cesarean section	174	45.2

Fistula characteristic

The proportions of women with none, mild, or moderate-to-severe vaginal scarring were 40 (10.4%), 180 (46.7%), and 165 (42.9%), respectively. The majority of the participants, 217 (56.4%), had a hole less than 2 cm in diameter, while 165 (42.9%) had a hole greater than 3 cm in diameter. A total of 262 (68%) participants had an intact bladder neck and 176 (45.7%) had a damaged urethra. Approximately 281 women (73%) had no circumferential defects. Regarding the duration of bladder catheterization, 24 (6.8%), 73 (19%), and 288 (74.8%) women underwent catheterization for less than 7, 7–10, and >10 days, respectively (Table 3).

Table 3.

Fistula characteristics of women who had obstetric fistula surgery at Mettu Hamlin Fistula Center, Southwestern Ethiopia (n = 385).

Variable	Category	Frequency	Percent
Scaring level	None	40	10.4
	Mild	180	46.7
	Moderate/severe	165	42.9
Width of fistula hole	Less or equal to 3 cm	220	57.1
	Greater than 3 cm	165	42.9
Length of fistula hole	Less or equal to 2 cm	217	56.4
	Between 3 and 5 cm	162	42
	Greater than 5 cm	6	1.6
Urethral status	Intact	209	54.3
	Damaged	176	45.7
Bladder neck status	Intact	262	68
	Partially damaged	116	30.2
	Completely damaged	7	1.8
Circumferential defect	Absent	281	73
	Present	104	27
Duration of bladder catheterization	Less than 7 days	24	6.2
	Between 7 and 10 days	73	19
	Greater than 10 days	288	74.8

Nutritional status of participants

Seventy-four percent of the participants weighed less than 50 kg. Nearly two-thirds (64.4%) of the women had a height >150 cm. The majority of the patients (297 (77%)) had a BMI lower than normal (<18.5 kg/m²) (Table 4).

Table 4.

Nutritional status of women who had obstetric fistula surgery at Mettu Hamlin Fistula Center, Southwestern Ethiopia (n = 385).

Variable	Category	Frequency	Percent
Weight (in kg)	< 50	294	76.4
	⩾50	91	23.6
Height (in cm)	<150	137	35.6
	⩾150	248	64.4
BMI (in kg/m2)	<18.5	297	77.1
	18.5–24.9	80	20.8
	⩾25	8	2.1

BMI: body mass index.

Proportion of obstetric fistula repair failure among participants

The proportion of OF repair failure among participants was 18.2% (95% CI = 14.6–22.3) (Figure 1).

Figure 1.

Proportion of fistula repair failure among women who had obstetric fistula failure at Mettu Hamlin Fistula Center, Southwestern Ethiopia (n = 385).

Associated factors with obstetric fistula repair failure

The multivariable logistic regression included eight variables (educational status, place of delivery, urethral condition, circumferential defect, fistula size, antibiotic use, height, and BMI) that were associated with OF repair failure at a p-value of less than 0.25 in a bivariable analysis. After adjusting for potential confounders, four variables—including place of delivery, urethral health, fistula size, and BMI—were found to be independently associated with OF repair failure (p < 0.05).

Fistula repair failure increases by fivefold (AOR = 5; 95% CI = 2.56–9.77) among women who gave birth at home as compared to those who gave birth at a health institution. In this study, participants with damaged urethras had a threefold increase in the likelihood of OF repair failure (AOR = 2.8; 95% CI = 1.47–5.44) than those who had intact urethras. The odds of OF repair failure were 4.6-fold (AOR = 4.6; 95% CI = 2.34–8.91) higher among women who had fistula sizes greater than 3 cm when compared to their counterparts. The odds of OF repair failure were nearly three times higher (AOR = 2.7; 95% CI = 1.10–6.79) among those who had a BMI less than 18.5 kg/m², as compared to those who had a normal BMI. The odds of fistula repair failure were nearly three times higher (AOR = 2.8; 95% CI = 1.47–5.44) among women whose urethra was damaged as compared to their counterparts. Moreover, the chances of developing OF repair failure were fivefold higher (AOR = 5; 95% CI = 2.56–9.77) among women who gave birth at home than among those who gave birth at a health institution (Table 5).

Table 5.

Results of the multivariable logistic regression among women had obstetric fistula surgery at Mettu Hamlin Fistula Center, Southwestern Ethiopia (n = 385).

Variable	Categories	Obstetric fistula repair failure		AOR (95% CI)	p-value
		Yes	No
Educational status	Have formal education	26 (6.8%)	85 (22.1%)
	Do not have formal education	44 (11.4%)	230 (59.7%)	0.62 (0.32–1.22)	0.174
Place of delivery	Health institution	35 (9.1%)	263 (68.3%)	(1)
	Home	35 (9.1%)	52 (13.5%)	5 (2.56–9.77)	<0.001
Urethral status	Intact	22 (5.7%)	187 (48.6%)	(1)
	Damaged	48 (12.5%)	128 (33.2%)	2.8 (1.47–5.44)	0.002
Circumferential defect	Absent	44 (11.4%)	237 (61.6%)	(1)
	Present	26 (6.7%)	78 (20.3%)	1.6 (0.59–2.26)	0.667
Fistula size	⩽3 cm	15 (3.9%)	205 (53.2%)	(1)
	>3 cm	55 (14.3%)	110 (28.6%)	4.6 (2.34–8.91)	<0.001
Antibiotics use	Yes	38 (9.9%)	78 (53.8%)	0.87 (0.46–1.64)	0.671
	No	32 (8.3%)	108 (28%)	(1)
Height	<150 cm	40 (10.4%)	208 (54%)	1.38 (0.72–2.62)	0.325
	⩾150 cm	30 (7.8%)	107 (27.8%)	(1)
BMI	<18.5 kg/m2	60 (15.6%)	237 (61.6%)	2.7 (1.10–6.79)	0.030
	⩾25 kg/m2	3 (0.8%)	5 (1.3%)	4.2 (0.53–32.3)	0.171
	18.5–24.9 kg/m2	7 (1.8%)	73 (19%)	(1)

BMI: body mass index; AOR: adjusted odds ratio.

(1) denotes reference category.

The values are bolded to emphasize the significantly associated variables.

Discussion

This study estimated the incidence of repair failure and identified its associated factors among women who underwent OF repair surgery at the Mettu Hamlin Fistula Center, Southwestern Ethiopia. Accordingly, 18.2% (95% CI = 14.6–22.3) of OF repair failures were found within the study area. In comparison to research conducted in Rwanda, where only 13.7% of OF repair failures have been reported; ¹⁹ the current proportion was higher. This discrepancy could be related to pre- and post-operative conditions and individual factors, such as nutritional status. This proportion was lower than that reported in studies conducted in West China (14.4%), ¹¹ Liberia (30%), ¹² Yirgalem, Southern Ethiopia (28.8%), ¹⁴ and Bahir Dar, Northern Ethiopia (35.3%). ¹³ This variation might be related, but not limited, to individual client characteristics, the degree of fistula, pre- and post-operative factors, and the degree of urethral injury.

Similar to previous findings,^7,9,10,13,14 the size of the fistula size was significantly associated with repair failure in the current finding. Accordingly, the likelihood of repair failure was more than four times higher among participants who developed a fistula size greater than 3 cm compared to those who had a fistula size less than or equal to 3 cm. This association may be attributed to the fact that the larger the wound edge, the higher the risk of infection and dehiscence.

In this study, the place of delivery was significantly associated with OF repair failure. Participants who gave birth at home had a fivefold higher chance of developing OF repair failure than those who gave birth at a health institution. This finding is consistent with the research conducted in Bahir Dar. ¹³ In reality, labor complications are extremely high when women give birth at home. As a result, severe injury to adjacent tissues, such as the bladder neck, may impede the healing of the repaired wound.

BMI less than 18.5 kg/m² was found to be a factor enhancing OF repair failure among the nutrition-related factors studied. The odds of repair failure were about threefold higher among participants whose BMI was less than 18.5 kg/m² as compared to those who had a BMI of 18.5–24.9. This could be related to poor wound closure due to impaired nutrition. This finding is in line with that of Hollander and Janszen. ⁷ Another piece of evidence has revealed that malnutrition is a risk factor for wound complications, including dehiscence. ²⁵

Furthermore, in this study, urethral involvement was associated with OF repair failure. Participants with damaged urethra had a nearly threefold higher chance of OF repair failure than those with intact urethra. This finding is supported by previous findings.^{13 –15} This could be related to persistent irritation of the wound site caused by urinary incontinence in cases of urethral damage.

Limitations of the study

To the best of our knowledge, this is the first study to assess the neglected conditions of reproductive-aged women in Southwest Ethiopia. In addition, the nutritional status of patients, which is an important factor affecting wound closure after surgery, was included in this study. A shortcoming of this study is that it uses secondary data. Therefore, future studies in this area should consider better designs that can show a cause–effect relationship.

Conclusion

The proportion of OF repair failures in the study area was lower than that in the majority, but not all, of previous local and global findings. This study also identified factors associated with repair failure. Accordingly, home delivery, damaged urethra, larger fistula size, and below-normal BMI (malnutrition) were found to be factors that enhance OF repair failure. Therefore, fistula management teams must strengthen pre- and post-operative care, including the assessment of the nutritional status, fistula size, and urethral injury in women to prevent early repair failure. In addition, maternal care providers should raise awareness of the negative outcomes of home delivery.