AFJOG

REVIEW management of a viable CSP include endogenous CSP, cross- over-sign-2, and a first-trimester myometrial thickness at the site of implantation of >4mm and implantation of the gestational sac above the uterine midline since the risk of placenta accreta syndrome is less. Patients without these features should be strongly counselled against keeping the pregnancy given the high risk of PAS that can reach 100% among women with CSP implanted within the niche. Even with these seemingly favourable features, all women with viable CSP who choose to proceed with expectant management should be advised to seek care at a tertiary hospital with adequate emergency obstetric, critical care, anaesthetic, and blood transfusion services. 6, 1,20,24,25 EXPECTANT MANAGEMENT OF A CSP WITH AN ABSENT EMBRYONIC HEARTACTIVITY CSP without foetal embryonic activity managed conservatively tends to result in an uncomplicated miscarriage. However, there may be a risk of between 3 - 30 % of uterine rupture in the first trimester, although usually not requiring a hysterectomy. Therefore, close observation with serial ultrasound and β-hCG is necessary to confirm pregnancy resolution or allow recourse to interventional treatment such as ultrasound-guided suctional curettage or local methotrexate Factors favouring less adverse outcomes of expectant management include declining levels of β-hCG for non-viable pregnancies. 6, 20, 26 PRIMARY CURETTAGE OF THE UTERINE CAVITY Uterine curettage with sharp curettes is strongly discouraged due to the high risk of severe haemorrhage. Successful treatment of carefully selected patients with suction curettage without severe haemorrhage or recourse to other methods of treatment has been reported among patients who fulfilled the following criteria: • When the gestational sac is <4 cm in diameter • A less-perfused implantation site with high vascular resistance • An anterior uterine wall thickness > 4 mm • A serum β-hCG of <15000 U/l 27 The procedure should be carried out under ultrasound guidance and blind curettage as a primary treatment for CSP is discouraged, as it is associated with inadequate retrieval of the products of conception and is often associated with severe haemorrhage and increased risk of uterine rupture. 28 Inadvertent misdiagnosis of exogenous as endogenous CSP with subsequent management with primary D&C results in severe intraoperative haemorrhage or uterine perforation, especially if ultrasound guidance is omitted. 27 Hence, apart from detailed pre-operative counselling and informed consent, adequate facilities for transfusion and emergency hysterectomy need to be in place before uterine curettage is attempted. Severe haemorrhage after the procedure can be minimized by the insertion of a Foley catheter. 6 The advantages of primary curettage are a success rate of >90% in well-selected patients, shorter duration of the procedure, and shorter hospital stays which lowers the costs when compared to the dual modality or treatment modalities. 27 METHOTREXATE LOCAL INJECTION Injection of methotrexate within the gestational sac as a single modality for the treatment of CSP treatment has been reported to yield favourable outcomes in 25/30 participants (86%) without complications of severe haemorrhage. 29 A single dose of ultrasound-guided local methotrexate 50 mg/2mL was used. Patients were then followed up with serum ß-hCG levels on days four and seven. If a reduction of >15% was achieved, patients were followed up with weekly ultrasound for assessment of sub trophoblastic blood flow, and weekly serum ß-hCG levels until the level was below 5 mIU/ml. Treatment failure and the need for additional intervention were identified as persistent sub- trophoblastic blood flow, or rising serum ß-hCG levels following local methotrexate injection.. B-hCG levels <47 000 IU/L and type 1 CSP were associated with favourable treatment outcomes. The advantage of methotrexate local injection is that it can be used successfully to manage CSP without surgical intervention. Furthermore, in this study, this mode of treatment was associated with less bleeding or systemic effects such as bone marrow suppression, stomatitis, nausea and vomiting. However, it can only be used for asymptomatic patients who are haemodynamically stable. 29 SYSTEMIC METHOTREXATE ALONE The overall success rate of systemic methotrexate has previously been reported to be between 54 and 69.2 % when intermittent doses of intramuscular or intravenous methotrexate (1mg/kg or 50mg/m2) were used. Therefore, the use of systemic methotrexate (a single dose followed by additional doses where necessary) did not receive much approval. Further analysis showed that the factors associated with the successful treatment outcome without major adverse effects from the medication or severe bleeding included gestational age ≤ 8 weeks, serum β-hCG concentration of ≤ 12,000 mIU/ml and absence of embryonic cardiac activity. 30-32 Successful treatment with high-dose systemic methotrexate for patients with interstitial ectopic pregnancy has been reported. 33 Patients with lower serum β-hCG (<20,000 U/l), absence of embryonic cardiac activity, a gestational age ≤7 weeks, gestational sac diameter of ≤21mm, and a crown-rump length of ≤8.6 mm seems to benefit the most from high-dose systemic methotrexate. 33 For carefully selected patients with SCP, systemic methotrexate has the advantage of potentially obviating the need for massive transfusion, especially where laparoscopic or hysteroscopic surgery and uterine artery embolisation are not readily available without major adverse effects from the medication. The main disadvantage is the long follow-up time that is necessary till the serum β-hCG is negative. 30,33,34 HYSTEROSCOPIC RESECTION OF CSP This is a highly effective intervention with success rates ranging from 65% to 96%. 35 The effectiveness is improved by neoadjuvant treatment with either systemic or local methotrexate or uterine artery embolisation that reduces the complications of severe haemorrhage. 36 Hysteroscopic resection is more suitable for CSP with a myometrial thickness of >3mm, and therefore more successful for endogenous, type 2 or COS 2 and 3 CSP. 37 The advantages are short operating time, rapid decline of serum β-hCG, and minimal blood loss. 35 It however requires skilled personnel and appropriate equipment making it more costly than medical treatment. African Journal of Obstetrics and Gynaecology | Volume 1 | Issue 2 | 2023 | 07