Collagen content and growth factor immunoexpression in uterine lower segment of type IA osteogenesis imperfecta: Relationship with recurrent uterine rupture in pregnancy

Pregnancy complicated by severe osteogenesis imperfecta poses a challenge for the anaesthetist: A case report

Pregnant women with severe osteogenesis imperfecta (OI) are uncommon, and there are limited data regarding anaesthesia for caesarean section in these high-risk individuals. The presence of anatomical and physiological abnormalities can pose technical challenges for the anaesthetist. This report describes the successful implementation of epidural anaesthesia in a parturient with severe OI. To our knowledge, this is the first documented use of ultrasound-assisted neuraxial anaesthesia and wrist blood pressure monitoring in such patients undergoing caesarean section. Understanding the pathophysiological changes associated with OI is crucial for ensuring safe administration of anaesthesia to these women.

Uterine wound healing after caesarean section: A systematic review

The rate of caesarean section (CS) is increasing worldwide. Defects in uterine healing have a major gynaecological and obstetric impact (uterine rupture, caesarean scar defect, caesarean scar pregnancy, placenta accreta spectrum). The complex process of cellular uterine healing after surgery, and specifically after CS, remains poorly understood in contrast to skin wound healing. This literature review on uterine wound healing was mainly based on histological observations, particularly after CS. The primary objective of the review was to examine the effects of CS on uterine tissue at the cellular level, based on histological observations. The secondary objectives were to describe the biomechanical characteristics and the therapies used to improve scar tissue after CS. This review was performed using PRISMA criteria, and PubMed was the data source. The study included all clinical and animal model studies with CS and histological analysis of the uterine scar area (macroscopic, microscopic, immunohistochemical and biomechanical). Twenty studies were included: 10 human and 10 animal models. In total, 533 female humans and 511 female animals were included. Review articles, meeting abstracts, case series, case reports, and abstracts without access to full-text were excluded. The search was limited to studies published in English. No correlation was found between cutaneous and uterine healing. The histology of uterine scars is characterized by disorganized smooth muscle, fibrosis with collagen fibres and fewer endometrial glands. As for skin healing, the initial inflammation phase and mediation of some growth factors (particularly connective tissue growth factor, vascular endothelial growth factor, platelet-derived growth factor, tumour necrosis factor α and tumour necrosis factor β) seem to be essential. This initial phase has an impact on the subsequent phases of proliferation and maturation. Collagen appears to play a key role in the initial granulation tissue to replace the loss of substance. Subsequent maturation of the scar tissue is essential, with a decrease in collagen and smooth muscle restoration. Unlike skin, the glandular structure of uterine tissue could be responsible for the relatively high incidence of healing defects. Uterine scar defects after CS are characterized by an atrophic disorganized endometrium with atypia and a fibroblastic highly collagenic stromal reaction. Concerning immunohistochemistry, one study found a decrease in tumour necrosis factor β in uterine scar defects. No correlation was found between biomechanical characteristics (particularly uterine strength) and the presence of a collagenous scar after CS. Based on the findings of this review, an illustration of current understanding about uterine healing is provided. There is currently no validated prevention of caesarean scar defects. Various treatments to improve uterine healing after CS have been tested, and appeared to have good efficacy in animal studies: alpha lipoic acid, growth factors, collagen scaffolds and mesenchymal stem cells. Further prospective studies are needed.

Incidence and outcomes of uterine rupture in women with unscarred, preterm or prelabour uteri: data from the international network of obstetric survey systems

OBJECTIVE

Analysis of atypical cases of uterine rupture, namely, uterine rupture occurring in unscarred, preterm or prelabour uteri.

DESIGN

Descriptive multi-country population-based study.

SETTING

Ten high-income countries within the International Network of Obstetric Survey Systems.

POPULATION

Women with unscarred, preterm or prelabour ruptured uteri.

METHODS

We merged prospectively collected individual patient data in ten population-based studies of women with complete uterine rupture. In this analysis, we focused on women with uterine rupture of unscarred, preterm or prelabour ruptured uteri.

MAIN OUTCOME MEASURES

Incidence, women's characteristics, presentation and maternal and perinatal outcome.

RESULTS

We identified 357 atypical uterine ruptures in 3 064 923 women giving birth. Estimated incidence was 0.2 per 10 000 women (95% CI 0.2-0.3) in the unscarred uteri, 0.5 (95% CI 0.5-0.6) in the preterm uteri, 0.7 (95% CI 0.6-0.8) in the prelabour uteri, and 0.5 (95% CI 0.4-0.5) in the group with no previous caesarean. Atypical uterine rupture resulted in peripartum hysterectomy in 66 women (18.5%, 95% CI 14.3-23.5%), three maternal deaths (0.84%, 95% CI 0.17-2.5%) and perinatal death in 62 infants (19.7%, 95% CI 15.1-25.3%).

CONCLUSIONS

Uterine rupture in preterm, prelabour or unscarred uteri are extremely uncommon but were associated with severe maternal and perinatal outcome. We found a mix of risk factors in unscarred uteri, most preterm uterine ruptures occurred in caesarean-scarred uteri and most prelabour uterine ruptures in 'otherwise' scarred uteri. This study may increase awareness among clinicians and raise suspicion of the possibility of uterine rupture under these less expected conditions.

Clinical manifestations of osteogenesis imperfecta in adulthood: An integrative review of quantitative studies and case reports

Osteogenesis imperfecta (OI) is a rare genetic disorder of the bones caused by a mutation in Type I collagen genes. As adults with OI are aging, medical concerns secondary to OI may arise. This integrative review sought to review, appraise, and synthesize the clinical manifestations faced by adults with OI. Four electronic bibliographic databases were searched. Published quantitative, qualitative, and mixed-methods studies, as well as case reports from 2000 to March 2019, addressing a clinical manifestation in adulthood, were reviewed. Eligible studies and case reports were subsequently appraised using the Mixed Methods Appraisal Tool and Case Report Checklist, respectively. Twenty quantitative studies and 88 case reports were included for review regardless of the varying methodological quality score. These studies collectively included 2,510 adults with different OI types. Several clinical manifestations were studied, and included: hearing loss, cardiac diseases, pregnancy complications, cerebrovascular manifestations, musculoskeletal manifestations, respiratory manifestations, vision impairment, and other clinical manifestations. Increased awareness may optimize prevention, treatment, and follow-up. Opportunities to enhance the methodological quality of research including better design and methodology, multisite collaborations, and larger and diverse sampling will optimize the generalizability and transferability of findings.

Anesthetic Management in a Gravida with Type IV Osteogenesis Imperfecta

Osteogenesis imperfecta (OI) is an inherited disorder of the connective tissues caused by abnormalities in collagen formation. OI may present many challenges to the anesthesiologist. A literature review reveals a wide range of implications, from basic positioning to management of the difficult airway. We present the anesthetic management of a 25-year-old gravid woman with OI, fetal demise, and possible uterine rupture, admitted for an exploratory laparotomy.

Closure of the uterine incision with one or two layers after caesarean section: a randomized controlled study in sheep

OBJECTIVE

To compare the quality of the uterine scar with one or two layer closure after caesarean section by studying biomechanical and pathological properties of the scar.

METHODS

A randomized controlled trial performed on eight term pregnant ewes assigned into two groups during caesarean according to type of uterine closure: single-layer or double-layer. Hysterectomy was performed 8 months after caesarean delivery. Tensile strength of all scars and of unscarred myometrium was measured. Pathological properties of the scars were analyzed histologically.

RESULTS

The force required to reach the yield point was similar between scarred and unscarred myometrium (p=0.96), and between the scars in single-layer and double-layer closure groups (p=0.65). There was a significant increase in fibrosis width on the superficial part of the uterus in the double-layer closure group compared to the single-layer group (p=0.02).

CONCLUSIONS

Double-layer uterine closure modified wound healing without significant change in biomechanical properties.

Severe secondary postpartum hemorrhage 3 weeks after cesarean section: alternative etiologies of uterine scar non-union

A case of secondary postpartum hemorrhage that occurred 3 weeks after cesarean section requiring total abdominal hysterectomy is reported. The patient's history and pathologic features of the removed uterus did not allow the authors to clearly recognize a previous reported cause of this potentially life-threatening complication. Alternative causes of the non-union of the uterine incision are suggested.

Uterine dehiscence in term pregnant patients with one previous cesarean delivery: growth factor immunoexpression and collagen content in the scarred lower uterine segment

OBJECTIVE

This study aimed at investigating the relationship between the occurrence of uterine dehiscence in term pregnant scarred uteri and the presence of altered biochemical behavior of the scarring process.

STUDY DESIGN

Collagen content and the expression of transforming growth factor-beta and its isoforms transforming growth factor-beta1 and transforming growth factor-beta3, connective tissue growth factor, basic fibroblast growth factor, vascular endothelial growth factor, platelet-derived growth factor, and tumor necrosis factor-alpha in myometrium of lower uterine segment were assessed in 19 otherwise healthy term patients with one previous cesarean delivery who were not in labor. We were searching for differences between patients who showed uterine dehiscence (9 cases) and patients who showed a normal-appearing scarred lower uterine segment (10 cases). We also evaluated all these features in lower uterine segment from unscarred uteri of 10 otherwise healthy patients who were not in labor.

RESULTS

In the case of uterine dehiscence, the scarred lower uterine segment showed a higher collagen content, a reduction of pan transforming growth factor-beta expression because of a marked decrease or absence of transforming growth factor-beta3, a reduction of connective tissue growth factor, an increase in basic fibroblast growth factor and a slight enhancement in vascular endothelial growth factor, platelet-derived growth factor, and tumor necrosis factor-alpha expression.

CONCLUSION

These findings contribute to meliorate our knowledge about uterine scar healing and allow us to hypothesize that uterine dehiscence of a scarred uterus may be related to altered biochemical behavior of the scarring process.