Venous thromboembolism prophylaxis in pregnancy: Are we adequately identifying and managing risks?

Pregnancy is a well-known risk factor of venous thromboembolism. We retrospectively reviewed case histories of 82 pregnant women who developed symptoms of venous pathology, thrombophlebitis, deep vein thrombosis (DVT) or pulmonary embolus (PE) while receiving care at our hospital. We found the VTE risk identification and documentation during their pregnancies were deficient resulting in the omission of appropriate thromboprophylaxis. Many confirmed VTE cases (antenatally or postpartum) were not on thromboprophylaxis prior to diagnosis despite having multiple risk factors. We recommend the use of a risk assessment tool by clinicians for accurate risk identification ensuring proper risk management at different stages of pregnancy.

Surgical anatomy of the mid-vagina.

AIM: The mid-vagina (MV) represents Level II of the vagina. The surgical anatomy of the MV has not been recently subject to a comprehensive examination and description. MV surgery involving anterior and posterior colporrhaphy represents a key part of surgery for a majority of pelvic organ prolapse (POP). METHODS: Literature review and surgical observations of many aspects of the MV were performed including MV length and width; MV shape; immediate relationships; histological analysis; anterior and posterior MV prolapse assessment and anterior MV surgical aspects. Unpublished pre- and postoperative quantitative data on 300 women undergoing posterior vaginal compartment repairs are presented. RESULTS: The MV runs from the lower limit of the vaginal vault (VV) to the hymen. Its length is a mean of 5 cm. Its shape in section overall is a compressed rectangle. Its longitudinal shape is created by its anterior and posterior walls being inverse trapezoid in shape. Histology comprises three layers: (i) mucosa; (ii) muscularis; (iii) adventitia. MV prolapse staging uses pelvic organ prolapse quantification (POP-Q). Anterior MV prolapse can be quantitatively assessed using POP-Q while posterior MV prolapse can be assessed with POP-Q or PR-Q. Around 50% of both cystocele and rectocele are due to VV defects. POP will increase anterior MV width and length. Native tissue anterior colporrhaphy is the current conventional repair with mesh disadvantages outweighing advantages. Posteriorly, Level II (MV) defects are far smaller (mean 1.3 cm) than Level I (mean 6.0 cm) and Level III (mean 2.9 cm). CONCLUSION: An understanding of the surgical anatomy of the MV can assist anterior and posterior colporrhaphy. In particular, if VV support is employed, the Level II component of a posterior repair should be relatively small.

Surgical anatomy of the vaginal introitus.

AIM: The vaginal introitus is the entrance to the vagina, encompassing the anterior and posterior vestibules and the perineum. The surgical anatomy of the vaginal introitus, the lowest level of the vagina, has not been subject to a recent comprehensive examination and description. Vaginal introital surgery (perineorrhaphy) should be a key part of surgery for a majority of pelvic organ prolapse. METHODS: Cadaver studies were performed on the anterior and posterior vestibules and the perineum. Histological studies were performed on the excised perineal specimens of a cohort of 50 women undergoing perineorrhaphy. Included are pre- and postoperative studies which were performed on 50 women to determine the anatomical and histological changes achieved with a simple (anterior) perineorrhaphy. RESULTS: The vaginal introitus is equivalent to the Level III section of the vagina, measured posteriorly from the clitoris to the anterior perineum then down the perineum to the anal verge. The anterior and posterior vestibules, with nonkeratinizing epithelium, extend laterally to the keratinized epithelium of the labia minora (Hart's line). The anterior vestibule has six anatomical layers while the posterior vestibule has three. The perineum has an inverse trapezoid shape. Perineorrhaphy specimens were a mean 2.9 cm wide and 1.6 cm deep. They show squamous epithelium with loose underlying connective tissue. There were no important structures seen histologically, for example, ligaments or muscles. Microscopically, only 6 (12%) were completely normal with 44 (88%) showing minor changes including inflammation and scarring. Considerable anatomical benefits were achieved with such a perineorrhaphy including a 27.6% increase in the perineal length and a 30.8% reduction in the genital hiatus. CONCLUSION: An understanding of the anatomy and histology of the vaginal introitus can assist with performing a simple and effective perineorrhaphy, the main surgical intervention at the vaginal introitus.

Profound Hypokalaemia Resulting in Maternal Cardiac Arrest: A Catastrophic Complication of Hyperemesis Gravidarum?

We present a case of a 39-year-old G8P6 Pacific Islander woman who at 15+5 weeks' gestation had an out-of-hospital cardiac arrest secondary to profound hypokalaemia which was associated with severe hyperemesis gravidarum (HG). Her clinical course after arrest was complicated by a second 5-minute cardiac arrest in the Intensive Care Unit (ICU) (pre-arrest potassium 1.8), anuric renal failure requiring dialysis, ischaemic hepatitis, and encephalopathy and unfortunately fetal demise and a spontaneous miscarriage on day 2 of admission. Despite these complications, she was discharged home 4 weeks later with a full recovery. Following a plethora of inpatient and outpatient investigations, the cause of her cardiac arrest was determined to be profound hypokalaemia. The hypokalaemia was presumed second to a perfect storm of HG with subsequent nutritional deficiencies causing electrolyte wasting, extracellular fluid (ECF) volume reduction, and activation of the renin-angiotensin-aldosterone axis (RAAS). This combined with the physiological changes that promote potassium wasting in pregnancy including volume expansion, increased renal blood flow, increased glomerular filtration rate, and increase in cortisol contributed to the patient having a profoundly low total body potassium level. This diagnosis is further strengthened by the fact that her pre- and post-pregnancy potassium levels were within normal limits in the absence of supplementary potassium. This case highlights the potentially life-threatening electrolyte imbalances that can occur with HG and the importance of recognising the disease, comprehensive electrolyte monitoring, and aggressive management in pregnancy.

Posterior vaginal compartment repairs: Does vaginal vault (level I) fixation significantly improve the vaginal introital (level III) repair?

INTRODUCTION: Limited data exist associating vaginal vault and introital defects before and after posterior repairs (PR). We hypothesize: (i) a positive association between the size of vaginal vault and introital defects preoperatively; and (ii) a positive association between the reduction of these defects postoperatively if vault fixation (sacrospinous colpopexy-SSC) is used with the PR. METHODS: In a cross-sectional study of 300 consecutive PRs, the following were measured pre- and immediately postoperatively: (i) from POP-Q: genital hiatus (GH-Level III); (ii) from PR-Q: perineal gap (PG-Level III), posterior vaginal vault descent (PVVD-Level I). The data for introital defects (GH, PG) were separated according to the need for vault fixation using a SSC due to a larger vaginal defect (PVVD over 5 cm). RESULTS: Mean (SD) preoperative GH and PG were both significantly larger in the SSC versus no SSC group: GH (3.73 [0.94] vs 3.36 [0.83] cm, P = 0.01); PG (2.91 [1.0] vs 2.61 [0.91] cm, P = 0.05). SSC performed with the PR (84%); not performed (16%) cases. The mean (SD) postoperative reduction in GH (antero-posterior) was significantly (29%-P = 0.002) greater-1.1 (0.69) cm (29.5%) in the SSC group and 0.77 (0.49) cm (22.9%) in the no SSC group. The decrease in the PG (transverse) was greater by 11% (0.05). CONCLUSIONS: Levels I and III defects are associated with PRs; preoperatively larger vaginal vault (PVVD over 5 cm) and larger introital defects (GH, PG). Postoperatively, vault fixation resulted in significantly greater reduction in the introital defects. SUMMARY: Vaginal vault fixation (SSC) significantly improves the vaginal introital repair.

Efficacy and safety of once daily low molecular weight heparin (tinzaparin sodium) in high risk pregnancy.

Low molecular weight heparin (LMWH) is widely regarded as the anticoagulant treatment of choice for the prevention and treatment of venous thromboembolism during pregnancy. However, previous studies have demonstrated that the pharmacokinetic profiles of LMWH vary significantly with increasing gestation. Consequently, it remains unclear whether LMWH regimens recommended for use in nonpregnant individuals can be safely extrapolated to pregnant women. The aims of this study were to assess the safety and the efficacy of tinzaparin sodium (Innohep) administered only once daily during pregnancy. A systematic retrospective review identified a cohort of 37 high-risk pregnancies which had been managed using tinzaparin 175 IU/kg once daily. In 26 cases, the index pregnancy had been complicated by development of an acute venous thromboembolism (17 deep vein thrombosis and nine pulmonary embolism). For each individual, case notes were examined and data extracted using a predetermined questionnaire. No episodes of recurrent venous thromboembolism were identified amongst this cohort of pregnancies managed using once daily LMWH administration. However, two unusual thrombotic complications were observed, including a parietal infarct in one patient, and a postpartum cerebral venous thrombosis in another. Once daily tinzaparin was well tolerated, with no cases of heparin-induced thrombocytopaenia, symptomatic osteoporosis, or foetal malformations. Tinzaparin dose modification based upon peak anti-Xa levels occurred in 45% of the cases examined. The present study is the largest study to have examined the clinical efficacy of once daily LMWH for use in pregnant women at high risk of venous thromboembolism. Our data support the safety and efficacy of antenatal tinzaparin at a dose of 175 IU/kg. In order to determine whether this once daily regimen provides equivalent (or indeed greater) thromboprophylaxis to twice daily LMWH regimens during pregnancy will require highly powered direct comparative studies.