Risk Factor for Urinary Bladder Injury During Caesarean Section

Abstract

Objectives:

During caesarean section (CS), the urinary bladder is at risk of getting injured due to its proximity to the uterus. Globally, with an upward trend in the CS rates, there is an upsurge in the complications associated with CS. Evaluating the risk factors of bladder injury will help in patient counseling and treating team preparedness, recognition, and remedial surgery.

Materials and Method:

This case-control study was conducted from January 2006 to December 2020. Eighteen subjects who had bladder injuries during CS from January 2006 to December 2020 were included in the study as cases. Subjects who had caesarean section without bladder injury (BI) were enrolled as controls. Two controls for each case were enrolled. Thirty-six controls were chosen as subjects who had a caesarean section before and after the case. The proforma was filled out for both cases and controls, with information on their demographics, obstetric history, intraoperative problems, and hospital stay. The type, size, and site of BI and detection time were recorded.

Result:

During the study period, 80,488 deliveries were conducted of which 32,022 caesarean sections (39.7%) were performed. Eighteen patients had BIs at the time of caesarean sections. Incidence of BI during caesarean section was 0.056% (18/32,022). Previous caesarean section, dense adhesions, and difficulty in forming a bladder flap were statistically significant risk factors for BI.

Conclusion:

Previous caesarean section is the most important risk factor for urinary BI during CS. Early detection and good repair have excellent prognosis.

Introduction

The incidence of caesarean section (CS) and repeat CS is increasing day by day. As a result, there is an upsurge in the rate of complications of CS. Due to the proximity of the urinary bladder to the uterus, it is at the highest risk of getting injured during CS. The incidence of bladder injury (BI) and ureteric injury is around 0.13–0.44% and 0.01%–0.08%, respectively.¹ BI should be anticipated in conditions like previous CS, previous abdominal surgery, emergency CS, trial of labor after CS, prolonged or advanced labor, distorted pelvic anatomy, and caesarean hysterectomy.^2,3 Women with more than three CS are at 5 times higher risk of bladder injury.^4,5 As the number of CS increases, the chances of adhesion also increase.^6,7 The adhesions that may develop between the bladder and uterus distort the anatomy making it challenging to identify and create a bladder flap. The expertise of the surgeon is also related to the incidence of BI.⁸

As compared with elective CS, emergency CS is more associated with BI.⁹ Moreover, if CS is performed in advanced labor chances of BI are increased owing to distortion in the anatomy of the upper and lower segments of the uterus.² BI has immediate and long-term implications including prolonged operative time, prolonged catheterization leading to urinary tract infection, kidney damage, and rarely vesicoureteric or vesicovaginal fistula. Therefore, it’s critical to recognize and treat urological damage intraoperatively. Patients should be counseled, a detailed consent form should be filled out preoperatively, and all the necessary precautions should be taken intraoperatively to detect and repair BI.¹⁰

This case-control study was designed to find risk factors, complications, and management of BI during CS.

Materials and methods

This case-control study was conducted in the Department of Obstetrics and Gynecology from January 2006 to December 2020. The institutional ethics committee of the Government Medical College and Hospital approved the study. Patients who had BI during CS from January 2006 to December 2020 were included in the study as cases. BI is defined as the full-thickness injury to the bladder wall requiring surgical repair. Patients who had CS without BI were enrolled as controls. Two controls for each case were included. Patients who had a CS immediately before and after the case preferably performed by the same surgeon and on the same day were elected as controls. Records of both cases and controls were retrieved from the medical record department. Patients who had BI during CS but were operated on in other hospitals were excluded owing to the lack of complete details.

Detailed information of both cases and controls regarding their demographic profile, obstetric history, intraoperative complications, and complete course during the hospital stay was filled in a proforma. Obstetrical history including any previous CS or any other abdominal surgery, number of CS, any complications in previous CS, the indication of present CS, intraoperatively adhesions in the abdominal wall, uterovesical pouch adhesions, or pulled-up bladder were noted. The type, size, and site of BI and the detection time were recorded.

Sample Size and Statistical Analysis

As the incidence of BI during CS is low, so all the patients with BI during CS were included in the study. Data was entered in Microsoft Excel 2010. Statistical analysis was done with the Stata 16.1 (Stata Corp). The mean or median was calculated for continuous variables. The significance of risk factors for BI was calculated by the Wilcoxon rank sum test and Fisher’s exact test. The data were analyzed using the student’s t-test or Fisher’s exact test to compare categorical variables and the Student’s t-test to compare continuous variables.

Results

This case-control study was conducted in the Department of Obstetrics and Gynecology from January 2006 to December 2020. During the study period, 80,488 deliveries were conducted, of which 32,022 CS (39.7%) were performed. The rate of CS has risen from 32.9% in 2006 to 47.5% in 2020. During this period, 18 patients had BI at the time of CS. The incidence of BI during CS was 0.056% in our study.

Table 1 shows the baseline and clinical characteristics in both cases and controls. Both cases and controls were comparable in age, parity, and gestational age. The comparable outcomes were found in the clinical characteristics like the number of previous CS, elective or emergency CS, and CS during labor. Between the cases and control groups, a statistically significant difference was found in the number of previous CS (0.002) and the type of anesthesia given during CS (<0.001).

Table 1.

Baseline and Clinical Characteristics of Cases and Control

Variable	Cases (n = 18)	Controls (n = 36)	p-value
Age (years)
<25	08 (44.4%)	23 (63.8%)
26–35	08 (44.4%)	13 (36.11%)	0.089
>= 36	02 (11.1%)	00 (0.00%)
Parity
Primigravida	01 (5.5%)	15 (41.66%)	0.06
Multigravida	17 (94.44%)	21 (58.33%)
Gestational age (weeks)
≤33 + 6	05 (27.8%)	01 (2.8%)
34–36 + 6	05 (27.8%)	09 (25%)	0.06
>=37	08 (44.4%)	26 (72.2%)
Number of fetus
Singleton	18 (100%)	32 (88.9%)	0.358
Multiple gestation	00 (0.00%)	04 (11.1%)
Number of previous caesarean section
0	03 (16.7%)	22 (61.1%)
1	10 (55.6%)	13 (36.1%)	0.002
2	04 (22.1%)	01 (2.8%)
≥3	01 (5.6%)	00 (0.00%)
Fetal presentation
Cephalic	17 (94.4%)	33 (91.7%)	1.00
Breech and other	01 (5.6%)	03 (8.4 %)
Labor	13 (72.2%)	29 (80.6%)	0.728
Type of caesarean section
Elective	00 (0.00%)	03 (8.3%)	0.529
Emergency	18 (100%)	33 (91.7%)
Type of anesthesia
Spinal	03 (16.7%)	34 (94.4%)
General	15 (83.3%)	02 (5.6%)	(<0.001)

Fifteen out of 18 cases had a history of previous CS. While in the control group, only 14 out of 36 had a history of previous CS. Intraoperative findings in cases and controls are shown in Table 2. Dense adhesions were found in 33.3% of the cases.

Table 2.

Intraoperative Findings in Cases and Controls

Variable	Cases	Control	p-value
Variable	(n = 18)	(n = 36)	p-value
Adhesions
No	07 (38.9%)	28 (77.8%)	0.004
Mild	04 (22.2%)	07 (19.4%)
Dense	06 (33.3%)	01 (2.8%)
Plastered	01 (5.6%)	0 (0.00%)
Bladder adherent
Yes	08 (44.4%)	10 (27.8%)	0.221
No	10 (55.6%)	26 (72.2%)
Bladder flap
Made	04 (22.2%)	36 (100%)	<0.001
Could not be made	14 (77.8%)	00 (0.00%)
Placental location
Upper uterine segment	15 (83.3%)	36 (100%)	0.033
Previa	02 (11.1%)	00 (0.00%)
Accreta	01 (5.6%)	00 (0.00%)
Uterine rupture
Yes	11 (61.1%)	00 (0.00%)	<0.001
No	07 (38.9%)	36 (100%)
Surgeon expertise
Junior resident	00 (0.00%)	02 (5.6%)	0.00
Senior resident	02 (11.1%)	34 (94.4%)
Consultant	16 (88.9%)	00 (0.00%)

In our study of the 18 cases with BI, 11 cases had uterine rupture as well. Uterine rupture was statistically significant with BI group (p = <0.001). These cases of BI with uterine rupture had a previous 1 CS in 8/11, a previous 2 CS in 2/11, and a previous 3 CS in 1/11 patients. Five of the cases of uterine rupture had undergone a hysterectomy.

Table 3 shows the characteristics of BI. In our study, directly visualizing Foley’s catheter in the peritoneal cavity was the most common method to detect BI (15/18). In 11/18 cases, BI was detected on opening the peritoneum. These were the cases that presented in labor and had uterine rupture preoperatively. Bladder dome was the most common site of injury, with a mean size of BI of 3.5 cm. In all the cases, BI was repaired in two layers with the placement of Foley’s catheter for 3–4 weeks. Suprapubic catheterization was done in 8 cases.

Table 3.

Characteristics of the Bladder Injury

Variable	Number of bladder injury (n = 18)
Time of bladder injury
Entry/preoperatively	11 (61.1%)
Formation of bladder flap	04 (22.2%)
Uterine incision	03 (16.7%)

Method of detection
Retrograde filling	02 (11.1%)
Visualization of Foley’s bulb	15 (83.3%)
Created iatrogenically	01 (5.6%)

Site
Anterior wall	01 (5.6%)
Posterior wall	02 (11.1%)
Dome	11 (61.1%)
Combined	03 (16.6%)
Vesicourethral	01 (5.6%)
Size
1–2cm	04 (22.2%)
3–4cm	08 (44.4%)
≥5cm	06 (33.3%)

Postoperatively, 4 cases were shifted to the intensive care unit. Two cases had surgical site infections. Pneumothorax developed in one case. Only one patient in the control arm had wound dehiscence.

Discussion

The urinary bladder is the most likely to be injured during CS. While the number of CS performed worldwide has increased, the frequency of bladder damage has stayed relatively constant over time.¹¹The Incidence of BI in our research was 0.056%, which is slightly less than the incidence found in the literature (0.13–0.44%)¹ but this difference is not significant. Despite the large cohort, we found no ureteric injury in our study; nonetheless, the incidence of ureteric injury (0.01%−0.08%) has been documented in the literature.¹

In our study, we analyzed the history of the previous CS was the most influential risk factor correlated with the incidence of BI. Previous research has consistently highlighted CS as a significant risk factor for BI, p-value <0.001.^1,12 Chill et al. conducted a comprehensive multivariate analysis of various risk factors associated with BI during caesarean procedures. Their findings revealed that a history of previous CS was associated with an odds ratio (OR) of 1.714 (95% confidence interval: 0.458–6.424), but the p-value was 0.424. Interestingly, despite this association, previous CS did not emerge as an independent risk factor for BI (p = 0.424). However, it’s important to note that Chill et al. grouped previous CS, malpresentation, and placental abnormality into a single category. Consequently, the exact number of patients with a history of previous CS in their cohort remains ambiguous. Additionally, a significant proportion of patients experienced BI due to the extension of the uterine incision while delivering the fetus at the time of CS. This factor could potentially explain the observed differences in the results by Chill et al.¹³

The number of previous caesarean sections in a patient has a positive correlation with BI. In the multivariate analysis conducted by Shahrani et al., the OR for BI associated with the number of previous CSs was 2.48, with a 95% confidence interval of 1.81 to 3.04.¹⁴ The most probable reason could be adhesions between the lower uterine segment and the bladder. Intrabdominal adhesions have been statistically significantly associated with BI. Studies by Radu et al. and Gungorduk et al. found a statistically significant association between intrabdominal adhesions and BI, with a p-value of 0.001.^1,12 So, a key surgical step to prevent BI during CS is a careful peritoneal entry.¹³

In our study, all patients in the cases group were operated as emergency CS, so the association of BI with elective versus emergency CS could not be made. However, a statistically significant difference had been reported of BI in emergency CS as compared with elective CS.^9,14

Various other intrapartum factors, which had been reported as risk factors for the BI, are the presence of labor, station of fetal parts deeper than or equal to +1, large baby size, active second stage of labor, and failed ventouse delivery were the independent factors for the BI during CS.^11–13 Difficult extraction of the fetus leads to extension of the uterine incision causing BI in these situations. Oliphant et al found a statistically significant risk of BI in advanced maternal age (p < 0.001). The exact reason for this association is not clear, but it may be related to the difficulty in extracting a large-sized baby during CS.¹¹ Urological injuries were significantly seen in CS done for placenta accreta spectrum (PAS) and complete placenta previa. (p-value = <0.01 for both).¹ In PAS, anatomical planes are distorted and bladder invasion by the placenta with enhanced vascularity makes the identification and dissection of anatomical planes challenging leading to BI.¹⁴ Unlike previous studies, we found that 61.1% (11 out of 18) of patients with BI experienced uterine rupture. In studies by Shahrani et al. and Chill et al., the incidence of uterine rupture was reported to be 0.04% and 5.9%, respectively.^13,14 This difference may be attributed to variations in prevalence antepartum and intrapartum care across different regions.

Our study discovered a statistically significant relationship between general anesthesia and BI (p < 0.001). However, no direct association was found between general anesthesia and BI. Of the 18 cases, 15 received general anesthesia due to hemodynamic instability. Similarly, Radu et al. observed a significant association between BI and the type of anesthesia (p < 0.001), noting that 75% of their case group underwent hemostatic caesarean hysterectomy, and 58.3% had PAS.¹ We also explored the association between BI and the experience level of operating surgeons. Our study found a higher incidence of BI during CS performed by senior consultants. However, these cases often involved more complex conditions, such as 11 cases of uterine rupture, 2 of placenta previa, and 1 of PAS. As per our hospital protocol, difficult cases are operated by a senior consultant. In contrast, all CS in the control group were performed by senior residents. This discrepancy may have resulted in a misleading association between surgeon expertise and BI occurrence. Oliphant et al. observed an increased incidence of partial thickness birth injuries during the first half of the academic year (p-value < 0.001), suggesting a correlation with the learning curve in a trainee environment. Therefore, training programs might consider assigning more experienced trainee assistants to higher-risk cases or implementing targeted educational initiatives early in the academic year.¹¹

Saqib et al. did a randomized control trial to study the role of retrograde bladder filling before the formation of bladder flap in preventing BI in patients with adhesions of previous CS. They included patients with previous two CS. The findings showed that the incidence of BI was significantly lower in the group that underwent retrograde bladder filling (2.8% vs. 20.6%, p < 0.0001). Additionally, the size of the BI was significantly smaller (p < 0.0001), and the number of perforations was also significantly reduced (p < 0.0001) in this group. Moreover, the repair of BI was found to be easier and safer in the retrograde filling group due to the higher location of the injuries.¹⁵ In our research, most of the cases of BI (11/18) were identified on opening the peritoneum. This was attributed to the preoperative involvement of the bladder along with uterine rupture. During uterine rupture, the uncontrolled breach in the uterine cavity often involves the bladder, especially if it is adherent and pulled up due to adhesions.

Anticipation of BI is extremely prudent so that suspicion and detection can be made intraoperatively. BI can be detected by direct visualization of urine leakage, visibility of Foley’s bulb in the operative field, extravasation of dye, visible detrusor laceration, or hematuria. In suspected cases, bladder injury must be determined, by retrograde filling or clamping the catheter. In the postoperative period, patients with BI may present with pain in the lower abdominal, paralytic ileus, oliguria, ascites, peritonitis, sepsis and at times, acute renal failure. BI has an excellent prognosis if recognized intraoperatively and is appropriately repaired.

Our study’s strength lies in its elaborate observational design, which includes a comparison group that has assessed a sizable sample size. Also, evaluation of various risk factors of BI during CS. Given the low prevalence of BI during CS, we conducted a retrospective study and acknowledge its inherent limitations. Bias for the risk factors can occur while taking data from the medical records. Furthermore, there can be under-reporting of data like the size of bladder injury, types of adhesions. Due to low incidence of BI adjusted analysis couldn’t be done. Compiling and analyzing data from various studies could be utilized to develop a personalized risk calculator for BI during CS.

Conclusion

The incidence of BI is quite low in cases of CSs. Adhesions secondary to previous CS is the most important risk factor for BI. A good repair and the least tissue trauma during primary CS might decrease adhesion formation. Also, early detection and proper repair of BI have excellent prognosis.

Footnotes

Authors’ Contributions

S.R.: Conceptualization, article writing, review, and editing. P.R.: Conceptualization, data curation, article writing, review, and editing. A.S. and V.B.: Article writing, review, and editing.

Author Disclosure Statement

The authors report that there are no competing interests to declare.

Funding Information

No funding was taken.

References

Radu

, Pristavu

, Vinturache

, et al. Risk Factors for Urological Complications Associated with Caesarean Section-A Case-Control Study. Medicina (Kaunas), 2022; 58(1):123; doi: 10.3390/medicina58010123

Manidip

, Soma

. Caesarean bladder injury—obstetrician’s nightmare. J Family Med Prim Care, 2020; 9(9):4526–4529; doi: 10.4103/jfmpc.jfmpc_586_20

Narava

, Pokhriyal

, Singh

, et al. Outcome of multiple caesarean sections in a tertiary maternity hospital in the United Arab Emirates: A retrospective analysis. Eur J Obstet Gynecol Reprod Biol, 2020; 247:143–148; doi: 10.1016/j.ejogrb.2020.01.035

Abdelazim

, Alanwar

, Shikanova

, et al. Complications associated with higher order compared to lower order caesarean sections. J Matern Fetal Neonatal Med, 2020; 33(14):2395–2402.

Makoha

, Fathuddien

, Felimban

. Choice of abdominal incision and risk of trauma to the urinary bladder and bowel in multiple cesarean sections. Eur J Obstet Gynecol Reprod Biol, 2006; 125(1):50–53.

Hesselman

, Hogberg

, Rassjo

, et al. Abdominal adhesions in gynaecologic surgery after caesarean section: A longitudinal population-based register study. Bjog, 2018; 125(5):597–603.

Tulandi

, Al-Sannan

, Akbar

, et al. Clinical relevance of intra-abdominal adhesions in cesarean delivery. Gynecol Surg, 2011; 8(4):399–403.

Wei

, Harley

, O’Callaghan

, et al. Systematic review of urological injury during caesarean section and hysterectomy. Int Urogynecol J, 2023; 34(2):371–389.

Khalil

, Flora

, Hagglund

, et al. Increased bladder injury rate during emergency and repeat cesarean section. J Turk Ger Gynecol Assoc, 2023; 24(2):97–100.

10.

Royal College of Obstetricians and Gynaecologists. Planned cesarean birth.consent advice no 14, august 20. Available from: https://www.rcog.org.uk/guidance/browse-all-guidance/consent-advice/planned-caesarean-birth-consent-advice-no-14/ [Last accessed: November 3, 2023].

11.

Oliphant

, Bochenska

, Tolge

, et al. Maternal lower urinary tract injury at the time of caesarean delivery. Int Urogynecol J, 2014; 25(12):1709–1714.

12.

Gungorduk

, Asicioglu

, Celikkol

, et al. Iatrogenic bladder injuries during caesarean delivery: A case control study. J Obstet Gynaecol, 2010; 30(7):667–670.

13.

Chill

, Karavani

, Reuveni-Salzman

, et al. Urinary bladder injury during caesarean delivery: Risk factors and the role of retrograde bladder filling. Int Urogynecol J, 2021; 32(7):1801–1806.

14.

Al-Shahrani

. Bladder Injury during Caesarean Section: A Case Control Study for 10 Years. Bahrain Medical Bulletin, 2012; 34:1–6. https://www.bahrainmedicalbulletin.com/september_2012/Bladder-Injury.pdf [Accessed November 03, 2023].

15.

Saaqib

, Iqbal

, Naheed

, et al. A randomized controlled trial of cystoinflation to prevent bladder injury in the adhesive disease of multiple caesarean sections. Sci Rep, 2020; 10(1):15297.