Ovarian torsion and laparoscopy in the paediatric and adolescent population

Abstract

A 9-year-old girl attended the emergency department with right-sided abdominal pain and vomiting. Due to history and following examination, an ultrasound was requested which demonstrated a large complex midline mass. The most likely diagnosis was ovarian torsion, for which the patient underwent laparoscopy, detorsion and ovarian cystectomy. Histology revealed a mature cystic teratoma. Although less common than in the adult population, it is important to consider ovarian torsion in children and adolescents. Presentation is usually with pain accompanied by vomiting and fever, although these symptoms are not always present. Current management is organ-sparing, with laparoscopy±cystectomy. We discuss the adaptations for this procedure with regard to the paediatric and adolescent population. Differences in the anatomy and physiology must lead to consideration for alterations in surgical technique and positioning to ensure the safest and best quality care for these young patients.

Background

Ovarian torsion is defined as complete or partial twisting of the ovary on its ligamentous supply. This twisting will ultimately compromise the ovarian circulation. Adnexal torsion occurs if the Fallopian tube is twisted together with the ovary. Ovarian or adnexal torsion is relatively rare in children, with an estimated incidence of 4.9 per 100 000 girls aged 1–20 years; however, it is an important differential diagnosis in girls presenting with abdominal pain.¹

Ovarian torsion is more common in patients after menarche, but occurs in all ages, even in neonates and in utero. The majority of neonatal and antenatal cases are associated with an ovarian cyst. However, in the adolescent population, as in adults, it can be seen with a normal ovary.¹

The risk factors for ovarian torsion include ovarian masses and cysts, reproductive age, previous torsion and pregnancy. The mechanism for torsion involves the ovary and the tube, twisting around both the suspensory and ovarian ligaments. It is also hypothesised that the ovarian ligament is elongated in premenarchal girls, and this may be a factor in causation. Ovarian torsion is more commonly found on the right side. This is thought to be due to the mobility of the caecum and ileum on the right side, compared with the fixed and often full sigmoid colon on the left. It is also suggested that the higher rate may be due to the higher detection rate due to investigations for possible appendicitis.¹

Ovarian torsion eventually leads to occlusion of the vascular supply, haemorrhagic infarction and necrosis of the ovary. However, due to the dual blood supply, partial torsion or intermittent detorsion, ovaries that appear necrotic on laparoscopy can often remain viable. The long-term effect on fertility is not known.¹

Clinical presentation of torsion is most usually with acute severe pain on either side of the abdomen or the pelvis, and is often intermittent in nature. Nausea and vomiting, fever and/or a palpable abdominal mass may be present. Other symptoms include gastrointestinal or urinary tract symptoms. There is no single symptom or sign that can confirm or exclude ovarian torsion. Premenarchal patients may present with non-specific symptoms. However, in a study looking at ovarian torsion in premenarchal patients, the main presenting symptoms were abdominal pain (92.3%) and nausea and vomiting (84.6%). Physical examination revealed abdominal tenderness in 25 cases (64.1%).²

Case presentation

A 9-year-old girl presented to the children’s assessment unit after being referred by her general practitioner with right iliac fossa (RIF) pain. She had been experiencing abdominal and groin pain intermittently over the previous 4 months. This had been treated as a groin strain since the patient is a gymnast. The pain had worsened over the previous 24 hours, and she had also vomited six times. She had abdominal pain when passing urine, felt feverish and had reduced appetite. On examination there was tenderness in the RIF with guarding. Initial differential diagnoses included urine infection, appendicitis and hip pathology. A plan was made for blood work including full blood count and C reactive protein (CRP), ultrasound of the abdomen and pelvis, and a surgical review.

Ultrasound on the afternoon of admission demonstrated a large complex mass measuring 7×7×9 cm in the midline superior to the bladder. A retracted clot was seen within the structure, and no ovary was seen separately. The patient was reviewed by the gynaecology consultant, and after examination and review of history and ultrasound findings a decision was made for laparoscopy for ovarian cystectomy±oophorectomy.

A three-port laparoscopy (10 mm infraumbilical, 10 mm LIF, 5 mm RIF) was performed on the same day as the admission. The findings included a torted, necrotic right tube and ovary with a large ovarian cyst. Insufflation and operating pressures were 25 mm Hg and 15 mm Hg, respectively. An ovarian cystectomy was carried out, with the capsule removed and the right ovary left in situ. Histology showed a torted 9×4×3 cm mature cystic teratoma with no atypical features. Tumour markers including cancer antigen 125, cancer antigen 19–9, alpha-fetoprotein, beta human chorionic gonadotropin, inhibin and lactate dehydrogenase were taken. Results were not available until after the surgery, and all were within normal ranges.

This case highlighted the challenges of managing paediatric patients with gynaecological emergencies within a department which does not routinely operate on the paediatric population. In this review we discuss the presentation of ovarian torsion premenarche and postmenarche. We also summarise the importance of recognising special considerations in this population, including differences in anatomy, physiology and possible alterations in surgical technique.

Investigations

Often non-specific biomarker inflammatory responses can be raised with ovarian torsion, such as an elevated white cell count or CRP and increased interleukin-6.^{1 3}

Ultrasound can aid in the diagnosis, with a sensitivity and specificity of 70% and 87%, respectively.⁴ Common findings of ovarian torsion in the paediatric population include asymmetric enlargement of the ovary, peripheral location of the follicles and midline location of the ovary. A mass or cyst within the ovary may also be present.⁵ The role of ultrasound Doppler is unclear, and normal blood flow does not necessarily rule out torsion.^{6 7} CT and MRI are also used, especially when patients have attended emergency departments with acute abdominal pain. Ultimately ovarian torsion is a clinical diagnosis, and unfortunately a normal scan does not rule out ovarian torsion and can often lead to delay in treatment.¹

Differential diagnosis

Differential diagnoses, depending on age and clinical symptoms, include appendicitis, pyelonephritis, renal stones, ruptured or haemorrhagic ovarian cysts, pelvic inflammatory disease (PID), or ectopic pregnancy.¹ Due to the nature of the pain and the ultrasound findings, ovarian torsion was thought to be the most likely diagnosis. The patient was premenarchal and not sexually active, making the likelihood of ectopic pregnancy or PID unlikely. Except for abdominal pain she had no other urinary symptoms and no abnormalities on urine testing, making a renal condition less likely. Appendicitis was a possibility. However, in this case, the presence of a mass on ultrasound indicated the possibility of ovarian pathology, which would increase the chance of ovarian torsion.

Treatment

Ovarian torsion is an emergency. The mainstay of management in the paediatric population is conservative and organ-sparing, involving laparoscopy and detorsion of the ovary±cystectomy.^8–12

Outcome and follow-up

The patient recovered well from her operation and was discharged the day after surgery. Histology showed a torted 9×4×3 cm mature cystic teratoma, with no atypical features. Follow-up ultrasound at 6 months showed no evidence of any recurrence of the cyst.

Discussion

It is usual practice to conserve the ovaries after detorsion. Studies have shown that ovaries which appear infarcted at the time of surgery may show evidence of follicular activity on ultrasound several weeks after conservative surgical management.¹³ If ischaemia and tissue necrosis have occurred, removal of the necrotic tissue would be advised. In the reported case the Fallopian tube was left in situ, as although it initially appeared necrotic there was evidence of tube viability after detorsion.

Laparoscopy compared with laparotomy typically allows for a shorter recovery time, and it may also reduce adhesion formation.¹⁴ Historically ovarian torsion was managed with oophorectomy. There were concerns that if there had been a cyst present, detorsion would risk leaving a potential malignancy in situ. However, ovarian malignancy is very rare in this population, and ovarian-sparing cystectomy is preferred when there is low suspicion for malignancy.¹⁵ Features that increase concern for malignancy on ultrasound and MRI include solid papillary projections, thick septations (>3 mm), and increasing complexity and size.¹⁶ Concern was also raised that detorsion alone would increase the risk of thromboembolism.¹² However, no evidence of thromboembolism caused by detorsion has been seen.¹²

When there is concern for possible malignancy, consulting with a specialist gynaecological oncology centre should be considered. Ovarian tumour markers should also be obtained prior to the procedure.¹² In the reported case tumour markers were obtained. However, the procedure was carried out prior to the results being available. The decision was made, in this case, to carry out detorsion and proceed with cystectomy during the same surgical session. Ultrasound and laparoscopy showed an ovarian teratoma. Majority of ovarian teratomas are benign, although there is a malignancy rate of 2%. Therefore, another option would have been to carry out detorsion locally and then liaise with a specialist centre. Definitive management at the specialist centre could be planned using tumour marker results and possible further imaging, including MRI.

There is currently no definite guidance on how to prevent recurrence of torsion. The role of oophoropexy or ovarian fixation remains controversial. Oophoropexy can be carried out laparoscopically where the ovary is plicated to the round ligament.¹⁷ Ovarian fixation is usually considered on a case-by-case basis, and may be beneficial if there is high risk of recurrence, especially if there is no ovarian cyst or a long ovarian ligament.^18–20

Preoperatively working with paediatric patients may present challenges. Consent may present issues, as well as differences with presentation and imaging modalities.¹² Perioperatively positioning of the patient may be different from the adult population.¹² A uterine manipulator may not be appropriate and may also not be required due to the small size of a premenarchal uterus.¹² If a manipulator is not required, then a supine position may be appropriate. A small swab, on a sponge holding forceps, placed in the posterior fornix for manipulation, may also be appropriate and may be considered. If access to the vagina is required during surgery, positioning will depend on the size of the patient. Some adolescents will fit adult stirrups for dorsal lithotomy position, and some hospitals will have paediatric stirrups available. If no appropriately sized stirrups are available, a frog-leg position may be adequate.¹² Vaginal cleaning may also have to be adjusted to prevent hymenal damage in children or non-sexually active adolescents. The size of the urinary catheter will also have to be considered, with a size 10 or 12 usually being appropriate in older children and adolescents.

Maximum insufflation pressures also need to be altered, depending on the age of the patient. The range is from 6 to 8 mm Hg in infants, 8–10 mm Hg in children, and 10–15 mm Hg in older children and adolescents. However, no standard age cut-offs have been reported, and it may be more dependent on a patient’s size.^{21 22} Potential contraindications to laparoscopic surgery in the paediatric population may include volume-dependent congenital heart disease or chronic lung diseases.^{21 22}

Anatomical differences in the paediatric population and their effects on surgery must also be considered.^{12 14} For example, the abdominal wall around the umbilicus is thinner in children and adolescents than it is in adults. The distance between the umbilicus and the major blood vessels is also shorter. Therefore, there is higher risk for major blood vessel injury, although it remains extremely rare.¹⁴ The upper margin of the bladder is also higher, carrying the risk of bladder injury during suprapubic port insertion.¹⁴ The uterine length has been demonstrated to be shorter in premenarchal girls compared with postmenarchal, and this could have an impact on placement of uterine manipulator and on the risk of perforation.²³ The ovaries also remain part of the abdominal organs in premenarchal children, and are often found above the pelvic brim.²⁴

Traditional techniques of entry during gynaecological laparoscopy include preinsufflation of the abdomen using a Veress needle, Hasson open entry and direct trocar entry with simultaneous laparoscopic visualisation.²⁵ Abdominal wall tissue laxity and strength vary greatly with age, and considerable force of entry may be required for trocar placement in adolescents.²⁶ With these anatomical differences, it has been suggested that the open entry technique may be the preferred method to avoid inadvertent entry complications.²⁷ Due to the differences in pliability of abdominal wall tissues, it may also be of benefit to anchor the ports with sutures or use balloon ports.²⁸ Fascial incisional herniation has also been shown to be more common in the paediatric population. Herniations through very small diameters (3 and 5 mm) have been described. Therefore, it has been suggested that smaller incisions be used if possible, and that routine fascial closure to all port sites may be beneficial for paediatric patients, especially those under 5.¹² However, it is acknowledged that incision size and instrument use may depend on other surgical factors. There is some discussion regarding single-incision laparoscopy; however, this requires specific equipment and training.²⁹ In some situations a mini-laparotomy approach may be considered for large benign adnexal lesions, with recovery comparable with that of laparoscopy.^{30 31}

Ovarian cyst fluid spillage can present a number of risks, including chemical peritonitis, pseudomyxoma peritonei and dissemination of malignant cells.³² Due to these risks there are several reported methods to prevent cyst spillage during surgery. Direct puncture and suction tube have been used, although cyst spillage may still occur with this method. Watanabe et al³² described a technique using a sterilised surgical sheet to cover the cyst through a small Pfannenstiel incision. The sheet prevents cyst spillage when it is punctured.³²

A Cochrane review³³ in 2009 looked at laparoscopy versus laparotomy for benign ovarian tumours. The findings showed laparoscopic surgery was associated with significantly less postoperative pain, fewer adverse events of surgery and a shorter length of stay in the hospital. Overall, the frequency of unintentional rupture of the cysts during operation was higher in the laparoscopy group than in the laparotomy group.³³ However, in the dermoid cyst group, there was no statistical difference between the laparoscopy and laparotomy arms in terms of adverse events.^{34 35} In cases where smaller cysts are encountered (<5 cm), there may also be an option for conservative management, with detorsion and follow-up with imaging and tumour markers, rather than cystectomy.

Learning points.

• Ovarian torsion should be considered when a female child or adolescent presents with lower abdominal pain and vomiting, although symptoms can be non-specific.

• Ultrasound may aid in the diagnosis, but a normal scan does not rule out torsion.

• Risk factors include ovarian masses and cysts, although these are not always present.

• Management is often conservative and organ-sparing, involving laparoscopy and detorsion of the ovary±cystectomy; however, liaison with a specialist centre, open procedures and conservative management with close monitoring may also play a role.

• Surgical technique may need to be adjusted in the paediatric population to ensure the best quality and safest care for these patients.