Uterocutaneous Fistula Following Cesarean Section

Author Information

Swaminathan G*, Warke H**, Mayadeo NM***
(* Third Year Resident, ** Associate Professor, *** Professor, Department of Obstetrics and Gynecology,  KEM Hospital, Mumbai, India.)

Abstract
Uterocutaneous sinus tract is indeed a rare phenomenon. These generally occur following uterine surgery. As these patients present with discharge from the scar site, they can be misdiagnosed as wound infection or abscess at the scar site. Clinical suspicion should be aided by radiological investigations mainly ultrasonography. Computed tomography or MRI may be done if required for confirmation. We present a case report of a sinus tract which developed after cesarean section extending from the skin upto the uterine fundus and later resulted into an uterocutaneous fistula. Failed conservative management in this case facilitated the need for exploratory laparotomy with excision of the entire fistulous tract.

Introduction

Sinus tract is an opening below the skin that can extend and create a dead space with potential for abscess formation. A fistula is an abnormal tract formed between two epithelial surfaces. Fistulas are generally  lined by granulation  tissue  but  can  get  epithelized.[1] Uterocutaneous fistulas are mostly seen postoperatively. Prompt diagnosis can be made with contrast enhanced computed tomography or MRI.[2] Uterine perforation due to a migrated laminaria tent or an intrauterine contraceptive device may also lead to the formation of an uterocutaneous fistula.[3] We present a case report of a discharging uterocutaneous sinus tract leading to a fistula following cesarean section.

Case Report

A 24 year old Para 2 Living 2 previous 2 LSCS came to our emergency department with complaints of tender swelling at the cesarean scar site. Patient had undergone an emergency lower segment cesarean section (LSCS) with bilateral tubal ligation seven months ago in view of previous LSCS not willing for vaginal birth. Intraoperatively there were dense adhesions between the omentum and the anterior uterine wall which were released and tied with linen. Postoperative course was uneventful and patient was discharged on day 7. Suture removal was done on day 10 and there was no wound discharge or gape. 
Six months later patient started noticing a 2 - 3 cm painful nodule at the suture line on left side. There was no fever or discharge from the nodule. She had no complaints of pain in abdomen or bowel or bladder complaints. Her menstrual history was normal. On examination, she perceived tenderness over the nodule. Ultrasound examination revealed a small collection of 1-2 ml extending from the fundus upto the skin surface. MRI pelvis showed features suggestive of an abscess underneath the skin scar site with extension into the intermuscular plane, reaching up to the anterior wall of the uterine fundus. Ultrasound guided tapping of this abscess was done and the pus was sent for culture and antibiotic sensitivity. It revealed growth of staphylococcus aureus species sensitive to linezolid, clindamycin and gentamicin. No acid fast bacilli were seen on ZN staining and TB PCR was negative. Patient was managed conservatively with linezolid based on her culture report and was discharged. 
A month later, she presented to us with complaints of watery discharge from the scar site on left side. On examination, she was clinically stable with all parameters normal. Pfannensteil scar was present with a sinus tract opening on the left side with induration and sero-purulent discharge. On vaginal examination, the uterus was bulky, anteverted, mobility appeared restricted; both fornices were free and non-tender. Blood investigations were normal. She underwent examination under anesthesia with probing of the sinus tract from the abdomen which revealed a sinus tract extending up to the uterus. Ultrasound examination revealed a sinus tract of about 2 -2.5 cm width extending from the fundus of the uterus upto the skin with surrounding inflammation. MRI pelvis, with instillation of saline through the sinus opening for better visualization of the tract, showed features suggestive of a sinus tract extending from the abdominal wall up to serosa of fundus of the uterus without evidence of any extension into the uterine myometrium or endometrium, or bowel or bladder. In view of above findings and failure of conservative management a decision for exploratory laparotomy with excision of the sinus tract was taken. Patient then gave history of bleeding through the sinus opening during the last menses.


Figure 1. Probe through the sinus tract opening on the skin.

Preoperative workup was done and the patient underwent exploratory laparotomy with sinus tract excision along with surgeons. Methylene blue dye was instilled into the sinus tract through the opening on the skin. Probe was inserted into sinus tract and tissue dissection done around the probe. Approximately 1 cm of skin and subcutaneous tissue around the sinus tract was excised. Rectus sheath around the sinus tract was dissected from underlying muscle and 1.5 cm of rectus sheath was excised. Rectus muscle was separated. Uterus was found to be adherent to parietal peritoneum and extension of sinus tract was noted up to the uterine fundus on left side as the entire tract was delineated with methylene blue.


Figure 2. Dissection of the sinus tract.

Abdomen was opened in layers till the peritoneum. Peritoneum was adherent to anterior abdominal wall. Sinus tact extended up to the uterine fundus on left side. Anterior wall of uterus was adherent to anterior abdominal wall.


Figure 3. Sinus tract seen extending up to the uterine fundus.

Multiple linen threads were seen which were cut and removed. Tubal ligation sites were seen on bilateral fallopian tubes at isthmic region. 2 x 3 cm cyst was noted on right ovary. Left ovary was normal. Bladder was advanced up to lower third of the anterior uterine wall. Sinus tract extending to left side of uterine fundus was excised by sharp dissection. Approximately 0.5 cm of myometrium was excised around the sinus tract and in the process, endometrial cavity was opened. Sinus tract delineated by methylene blue was excised completely.


Figure 4. Uterus after excision of the sinus tract showing opened endometrial cavity.


Figure 5. Uterine fundus after suturing.

Endometrium was approximated with no. 2- 0 in continuous interlocking manner. Myometrium was approximated with polyglactin no.1-0 in 2 layers. Intraperitoneal drain was inserted and abdomen closed in layers. Postoperative course was uneventful and she went home on day 7.
Discussion

A fistula is an abnormal tract formed between two epithelial surfaces. Fistulas are generally lined by granulation tissue but they can get epithelized. Most fistulas arise as a result of trauma or after some kind of infectious process resulting in disruption of the continuity of the tissues involved.[4] Septic abortion caused by insertion of laminaria tent into the cervix leading to uterocutaneous fistula was reported by Gupta et al.[5] LSCS as a cause of uterocutaneous fistula was reported by Jain et al.[6] Other causes of uterocutaneous fistulas include: previous history of abdominal surgeries, improper closure of uterine incision following cesarean section, intra-abdominal sepsis in previous scar and secondary abdominal pregnancy. Once a fistula is diagnosed, the basic principle in the treatment is to obliterate the entire fistulous tract. There is no role of conservative management for fistula. Our patient had a sinus tract which extended from the skin upto the uterine fundus which later became an uterocutaneous fistula which had most probably developed as a result of foreign body reaction to the linen that was used for adhesiolysis during her cesarean section. Initially conservative management was tried but later surgical excision of entire fistulous tract had to be done after which the patient's symptoms settled.

References
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Citation

Swaminathan G, Warke H, Mayadeo NM. Uterocutaneous Fistula Following Cesarean Section. Volume 3 No. 8. Available from: http://www.jpgo.org/2016/08/uterocutaneous-fistula-following.html