Isthmoceles - Accuracy of imaging diagnosis and clinical correlation with histology: A prospective cohort study

Background

Isthmoceles are a growing clinical concern.

Objectives

To evaluate the accuracy of diagnosis of isthmoceles by imaging and to correlate the dimensions with clinical symptoms and histopathology.

Materials and Methods

Prospective study of women (n=60) with ≥1 C-section undergoing hysterectomy. Isthmoceles were measured by imaging before surgery and macroscopically on the specimen after hysterectomy, followed by histological analysis.

Main outcome measures

Accuracy of isthmocele diagnosis, correlation with clinical symptoms, and histopathological findings.

Result

By imaging, isthmoceles were slightly deeper (P=0.0176) and shorter (P=0.0045) than macroscopic measurements. Differences were typically small (≤3mm). Defined as an indentation of ≥2 mm at site of C-section scar, imaging diagnosed 2 isthmoceles consequently not seen by histology and missed 3. Number of prior C-sections increased isthmocele severity but neither the incidence nor the remaining myometrial thickness (RMT) did. Severity correlated positively with symptoms and histology. However, clinical use was limited. Histological analysis revealed presence of thick wall vessels in 100%, elastosis in 40%, and adenomyosis in 38%. Isthmocele lining was asynchronous with the menstrual phase in 31%.

Conclusions

Dimensions of isthmoceles by imaging were largely accurate with occasionally large differences observed. Number of C-sections did not increase isthmocele incidence, only severity. Indication for surgery remains clinical, considering dimensions and symptoms.

What is new?

Dimensions of isthmoceles should be confirmed before surgery since uterine contractions might change those dimensions. Symptoms increase with dimensions of isthmoceles but are not specific. Endometrial lining within the isthmocele can be asynchronous with the menstrual phase.

Ultrasonographic assessment of abnormal fetal growth related to uteroplacental-fetal biometrics and Doppler (U-AID) indices: Protocol for multicenter retrospective cohort study trial

Fetal growth restriction (FGR) is one of the leading causes of perinatal morbidity and mortality. Many studies have reported an association between FGR and fetal Doppler indices focusing on umbilical artery (UA), middle cerebral artery (MCA), and ductus venosus (DV). The uteroplacental-fetal circulation which affects the fetal growth consists of not only UA, MCA, and DV, but also umbilical vein (UV), placenta and uterus itself. Nevertheless, there is a paucity of large-scale cohort studies that have assessed the association between UV, uterine wall, and placental thickness with perinatal outcomes in FGR, in conjunction with all components of the uteroplacental-fetal circulation. Therefore, this multicenter study will evaluate the association among UV absolute flow, placental thickness, and uterine wall thickness and adverse perinatal outcome in FGR fetuses. This multicenter retrospective cohort study will include singleton pregnant women who undergo at least one routine fetal ultrasound scan during routine antepartum care. Pregnant women with fetuses having structural or chromosomal abnormalities will be excluded. The U-AID indices (UtA, UA, MCA, and UV flow, placental and uterine wall thickness, and estimated fetal body weight) will be measured during each trimester of pregnancy. The study population will be divided into two groups: (1) FGR group (pregnant women with FGR fetuses) and (2) control group (those with normal growth fetus). We will assess the association between U-AID indices and adverse perinatal outcomes in the FGR group and the difference in U-AID indices between the two groups.

Abnormal Uterine Involution May Lead to Atony and Postpartum Hemorrhage: A Hypothesis, With Review of the Evidence

Uterine involution has 2 major components-(1) involution of vessels; and (2) involution of myometrium. Involution of vessels was addressed by Rutherford and Hertig in 1945; however, involution of myometrium has received little attention in the modern literature. We suggest that the pathophysiology of myometrial involution may lead to uterine atony and postpartum hemorrhage. The myometrium dramatically enlarges due to gestational hyperplasia and hypertrophy of myocytes, caused by hormonal influences of the fetal adrenal cortex and the placenta. After delivery, uterine weight drops rapidly, with physiologic involution of myometrium associated with massive destruction of myometrial tissue. The resulting histopathology, supported by scientific evidence, may be termed "postpartum metropathy," and may explain the delay of postpartum menstrual periods until the completion of involution. When uterine atony causes uncontrolled hemorrhage, postpartum hysterectomy examination may be the responsibility of the perinatal pathologist.Postpartum metropathy may be initiated when delivery of the baby terminates exposure to the hormonal influence of the fetal adrenal cortex, and may be accelerated when placental delivery terminates exposure to human chorionic gonadotrophin (HCG). This hypothesis may explain why a prolonged third stage of labor, and delays in management, are risk factors for severe hemorrhage due to uterine atony.

The relationship of myometrial histopathology (metropathy) to myometrial dysfunction and clinical manifestations

Myometrial morphology and myometrial physiology have been considered to be separate entities; however, observations of myometrial morphology and associated dysfunctions suggest a relationship between myometrial morphology and myometrial physiology that deserves further exploration. Although myometrial electrical activity can be monitored by electrohysterogram, the association of increased myometrial contractions with an increase in electrical activity (due to an increase in gap junctions) is typically not evaluated. Although the association of increased myometrial contractions with increase in pain can be monitored by tocometry and intrauterine pressure catheters, respectively, this is generally not done in the non-pregnant uteri. Although standard morphologic evaluations routinely include evaluation with special stains and immunohistochemistry in other organ systems, such as skeletal and cardiac muscle, these evaluations are not standard or routine for myometrium in hysterectomies. The purpose of this review is to discuss non-neoplastic myometrial histology, with consideration of the potential value of using tools to measure variations in myometrial physiology, in order to reliably correlate myometrial histology with myometrial function (and dysfunction).

The pathogenesis of abnormal uterine bleeding in myopathic uteri

It has been suggested that impaired venous drainage and endometrial vascular ectasia (EMVE), secondary to increased intramural pressure, explains abnormal bleeding in fibroid uteri. Striking EMVE with extravasated red blood cells (ecchymosis) has also been seen in uteri with grossly obvious myometrial hyperplasia (MMH), suggesting that increased intramural pressure can cause EMVE in the absence of fibroids. EMVE with MMH may explain the century old association of clinically enlarged uteri with abnormal bleeding, and this same mechanism may be operative in myopathic uteri with grossly obvious adenomyosis. EMVE with associated thrombosis, ecchymosis, and/or stromal breakdown is commonly seen in random sections of hysterectomies for bleeding. EMVE may also be associated with endothelial hyperplasia, consistent with a reaction to endothelial injury due to impaired venous drainage. This further supports the theory that EMVE bleeds when thrombosis occurs, due to Virchow's Triad (stasis, endothelial injury, and hypercoagulability). EMVE may be "the lesion for which surgery was performed" in hysterectomies with otherwise unexplained bleeding.

A Comparison of Hysterectomies for Bleeding With Hysterectomies for Pain

Objectives. We recently suggested that increased intramural pressure may often explain pain and/or bleeding. Hysterectomies for bleeding tend to have outward bulges and endometrial vascular ectasia, while hysterectomies for pain tend to have deflection of pressure inward by subserosal ridges, which promote inner myometrial elastosis (IME). Study design. We analyzed causes of increased intramural pressure in 58 hysterectomies for pain and/or bleeding, excluding clinically fibroid uteri and prolapsed uteri. Postfixation photographs were used to avoid missing grossly obvious myometrial hyperplasia (MMH). Results. The most common cause of increased intramural pressure was grossly obvious MMH in 40/58 cases (69%). Other causes included clinically occult myomas (3 cases), adenomyosis (6 cases), and multifactorial causes (7 cases). Hysterectomies for bleeding weighed more than hysterectomies for pain ( P = .035). Hysterectomies for pain had more IME than hysterectomies for bleeding ( P = .029). Conclusions. When subserosal ridges deflect pressure inward, bulky MMH may cause pelvic pain and IME, but when they do not, bulkier MMH in heavier uteri may lead to both outward bulges and abnormal bleeding from endometrial vascular ectasia.

Placenta Increta Presenting as Retained Placenta: A Report of 3 Cases

OBJECTIVES

Morbid adherence is a risk factor for retained placenta (RP). We encountered three cases of placenta increta presenting clinically as delayed postpartum hemorrhage.

METHODS

This was a retrospective study of three cases of placenta increta presenting as RP.

RESULTS

One "routine" term placenta had heavy bleeding 2 weeks later; one missed abortion at 16 weeks with fetal and placental tissue submitted, had heavy bleeding 6 weeks later; and one elective abortion (no tissue submitted), had delayed postpartum bleeding leading to a curettage with blood only, then 6 weeks later a hysterectomy for menorrhagia. All 3 pathology specimens showed necrotic villi. However, all three also showed myometrium with keratin-positive interstitial trophoblasts in a zone of damaged myometrium, consistent with increta. All three cases had basal plate myofibers (BPMF) in the placenta, with BPMF recurrence in the two cases with another pregnancy.

CONCLUSION

RP may be a presenting clinical manifestation of placenta increta.