Scar ectopic pregnancy

Dr. Alka Pandey

1. SCAR ECTOPIC PREGNANCY Dr. Alka Pandey MD, Ph.D., Associate Professor, P.M.C.H., Patna

2. Scar pregnancy is an ectopic pregnancy implanted in the myometrium at the site of a previous CS Scar. It was first described in 1978 by Larsen and Soloman .

3. Prevalence Prevalence of CSP is increasing and to date more than 1000 cases have been reported. This may be attributed to : Increasing Number of CS Increasing awareness Better diagnostic technique

4. Risk Factors May occur after any myometrial trauma - Caesarean Section Manual Removal of placenta Myomectomy D & C

5. Pathophysiology Endometrial and myometrial disruption of scar are predisposing factors. Invasion by the implanting blastocyst through a microscopic tract that develops from the trauma of an earlier CS. The risk of scar implantation might be proportional to the size of the anterior uterine wall defect. Caesarean section for a breech presentation in a previous pregnancy appears to be most frequently at risk of future CSP.

6. Pathophysiology May be secondary to : Systemic diseases – DM (Poor blood flow) Poor tissue quality - Inadequate collagen formation Post operative wound infection Short interval pregnancy Improper closure

7. Diagnosis History of amenorrhoea followed by bleeding. Positive pregnancy test Trans vaginal ultrasound

8. Diagnosis Ultrasound criteria : - Empty uterine cavity , closed and empty cervical canal Placenta and/or a gestational sac embedded in the scar of a previous caesarean section A triangular/round or oval‐shaped gestational sac that fills the niche of the scar A thin or absent myometrial layer between the gestational sac and the bladder Yolk sac, embryo and cardiac activity may or may not be present Evidence of functional trophoblastic /placental circulation on colour flow Doppler examination, characterised by high velocity and low impedance blood flow Negative ‘sliding organs’ sign

9. Diagnosis Trans abdominal pelvic ultrasound is particularly useful in later gestation when a trans vaginal scan may not provide panoramic view.

10. Diagnosis TVS 3D ultrasound with Power Doppler identifies peritrophoblastic vascular flow in the tissue surrounding the sac and measurement of the myometrial thickness is relatively easier.

11. Diagnosis MRI is also a useful adjunct.

12. Hysteroscopic Diagnosis

13. Naked eye / laparoscopic picture

14. Classification Type-1 or endogenic – where implantation occurs on the scar and the gestational sac grows towards the cervico isthmic or uterine cavity. Type-2 or exogenic – CSP occurs when the gestional sac is deeply embedded in the scar and the surrounding myometrium and grows towards the bladder.

15. Types of Scar Ectopic Pregnancy

16. Classification The myometrial layer between the gestational sac and the bladder becomes very thin and may disappear with bulging of the gestational sac through the gap as the pregnancy advances. In two – third of the cases the thickness of the scar may be less than 5 mm.

17. Clinical Presentation Asymptomatic – 37% Painless vaginal bleeding – 39% Generalized abdominal pain – 25%

18. Differential Diagnosis Inevitable miscarriage with a low lying sac – In an impending miscarriage the gestational sac is often irregular and located within the uterine cavity with absent or minimal colour Doppler flow. Gentle pressure at the level of the internal os may displace the gestational sac – sliding sign.

19. Differential Diagnosis Cervical ectopic pregnancy – Present in or close to the cervical canal with ballooning of the cervix. Good colour flow Doppler and a negative sliding sign.

20. Risk factors influencing management choices Management Patient factors Symptoms Fertility wishes Acceptability of prolonged follow up Associated lesions Surgical risk factors Response to initial treatment

21. Management Caesarean scar pregnancy (CSP) Gestational age Human chorionic gonadotropin ( hCG ) levels Size of CSP mass Type of CSP Myometrial thickness Viability Facilities Interventional radiology Surgical expertise/facilities Monitoring facilities

22. Management No consensus on the preferred mode of treatment. All treatment options carry a risk of haemorrhage and subsequent hysterectomy. Treatment should be individualized based on full pre-treatment evaluation. Pregnancy should be ended as soon as possible after confirming the diagnosis.

23. Management Expectant management – Used very rarely in selected cases Patient must be in stable condition and thoroughly counseled. Close monitoring Minimal symptoms Compliant Type – 1 CSP Declining beta HCG No fetal cardiac activity

24. Management Medical management – Candidates – Less than 8 weeks pregnancy Absent fetal cardiac activity Stable Beta HCG <5000 – 12000 IU Myometrial thickness between bladder and gestation sac >2 mm Systemic methotrexate Single dose 1 mg/kg or 50 mg/cm 2 IM at an interval of 2 or 3 days three or four doses.

25. Management Local injection and embolisation – Local injection of methotrexate with sac aspiration Local injection of other embryocides

26. Management Surgical management Dilatation and surgical evacuation Hysteroscopic resection Vaginal excision and resuturing Laparoscopic excision and resuturing Open excision and resuturing Combined laparoscopic and hysteroscopic procedure Combined laparoscopic and vaginal surgery Hysterectomy

27. Management Combined or sequential management – Uterine artery embolisation / chemoembolisation followed by dilatation and evacuation/surgical resection in 24–48 hours Methotrexate followed by surgical evacuation or resection after an interval

28. Intrauterine Balloon Catheter – can be used successfully to compress the gestational sac. Catheter is left for 48 hours Antibiotics given Outer end of the catheter is fastened to the thigh.

29. Prevention Avoid pregnancy 12 to 24 months. Surgical repair of uterine scar defects with single or double layer closure.

30. Summary CSP is an uncommon but potentially life-threatening condition. The incidence is rising as CSR is rising. Precursor of morbidly adherent placenta. Do not confuse CSP with ectopic pregnancy. Early diagnosis is important. TVS is the most effective and preferred diagnostic tool. Determine whether heart activity is present.

31. Summary If heart activity is documented: Counsel the patient. Inform the patient of the risks of pregnancy continuation. If continuation: an additional counseling session: risks should be explained. If termination: a reliable treatment that stops fetal heart beat without delay.

32. Summary Avoid single treatments as they are unlikely to be effective: D&C Suction curettage Single-dose IM MTX, and UAE Removal of Scar ectopic by any of the following (Hysteroscopy, Laparoscopy, Laparatomy , Vaginally) and resuturing of the scar

33. Summary Consider combination treatments: best results. direct injection of MTX or Kcl into GS with TVS guidance. In a future pregnancy, an early visit for TVS is important.

34. Complications Placenta previa / accreta Uterine rupture Massive Haemorrhage : increased maternal morbidity and mortality. 

35. Thank You