Morphometry of Placentae of Anaemic and Non-anaemic Preeclamptic Patients

Background The etiology of preeclampsia (PE) still remains elusive. Nevertheless, early onset PE has been hypothesized to develop following defective implantation of the conceptus into the endometrium and subsequent placentation. Defective placentation leads to insufficient remodeling of spiral arteries thus hypoperfusion of the placenta and clinical manifestations. Anaemia is highly prevalent amongst pregnant women. It is postulated that hypoxia is one of the mechanisms by which PE develops. The severity of symptoms seen in patients with coexisting preeclampsia and anaemia has been linked to uteroplacental insufficiency. Few studies however, have defined the placental morphometry when the two conditions occur concurrently.   Methods This unmatched case-control study was carried out at the Kenyatta National Hospital where 42 placentae were obtained; 21 from preeclamptic mothers who had anaemia in the first and third trimesters of pregnancy (cases) and 21 from preeclamptic mothers without a history of anaemia in pregnancy (controls). The tissues were obtained and macroscopically and microscopically examined to determine relative differences. Photographs of the placentae were taken using a 12 MP (f/1.8, 26mm wide, 1/2.55", 1.4μm, dual pixel PDAF, OIS) camera. Photomicrographs were taken using a ZeissTM digital photomicroscope at ×400 magnification for stereological analysis. SPSS (Version 25.0) was used to input data where median values, interquartile ranges and frequency tables were obtained. Mann-Whitney U tests were run to compare differences in medians of the clinical, gross and histological features between the 2 groups. A p-value of ≤ _0.05 was considered statistically significant.   Results Hemoglobin levels in the anemic group ranged between 7.0-10.5 g/dl in the 1st trimesters and 7.6-10.9g/dl in the 3rd trimester with patients being mild to moderately anemic. Gross placental infarction was observed in 17/21 (81.0%) of the cases and 15/21 (71.4%) of the controls. The gross morphometric parameters that were lower in cases were the placental weight and volume (p-values of <0.001, 0.001 respectively). The histopathological features observed were extensive perivillous and intervillous fibrin deposition and larger volumes of syncytial knots in the case group. The harmonic mean thickness of the interhaemal membrane was higher in the cases when compared to controls (p -value: <0.001). The estimated mean morphometric diffusing capacity was higher in cases when compared to controls (p-value: 0.001).   Conclusion The frequency of gross and histopathological lesions seen in the PE placentae was increased when the patients had both preeclampsia and anaemia. Anaemia may thus exacerbate the pathology caused by preeclampsia. This may be the structural basis for the uteroplacental insufficiency observed when the two morbidities co-exist. It may therefore be prudent for clinicians to monitor maternal hemoglobin levels, in order to reduce the severity of preeclampsia when the two conditions co-exist.  

Surgical anatomy of the accessory middle colic artery: a meta-analysis with implications for splenic flexure cancer surgery

AIM

Surgical resection of splenic flexure cancers (SFCs) is technically demanding due to the complex regional anatomy, characterized by the presence of embryological adhesions, close proximity to the pancreas and spleen, and a highly heterogeneous arterial supply and lymphatic drainage. The accessory middle colic artery (AMCA) is increasingly being recognized as an important source of blood supply to the splenic flexure. The aim of this study is to determine the prevalence and anatomical features of the AMCA.

METHOD

A systematic search of the scientific literature was conducted on PubMed and Embase from inception to November 2020 to identify potentially eligible studies. Data were extracted and prevalence was pooled into a meta-analysis using MetaXL and Meta-Analyst software.

RESULTS

A total of 16 studies (n = 2203 patients) were included. The pooled prevalence (PP) of the AMCA was 25.4% (95% CI 18.1-33.4). Its prevalence was higher in patients without a left colic artery (LCA) (PP = 83.2%; 95% CI 70.4-93.1). The commonest origin for the AMCA was the superior mesenteric artery (PP = 87.9%; 95% CI 86.4-90.7). The AMCA shared a common trunk/gave rise to pancreatic branches in 23.1% of cases (95% CI 15.3-31.9).

CONCLUSION

The AMCA contributes to the vascularization of the splenic flexure in approximately 25% of individuals, and may be an important feeder artery to SFCs, especially in the absence of a LCA. Preoperative identification of this artery is important to ensure optimal surgery for SFC and minimize complications.

The prevalence of the Rouviere's sulcus: A meta-analysis with implications for laparoscopic cholecystectomy

Rouvière's sulcus (RS) is increasingly being recognized as an important extra-biliary landmark during laparoscopic cholecystectomy (LC). The aim of this study was to conduct a systematic analysis of the prevalence and morphological types of RS. A systematic search was conducted through the major databases PubMed, ScienceDirect, Google Scholar, China National Knowledge Infrastructure (CNKI), SciELO, and the Cochrane Library to identify studies eligible for inclusion. The data were extracted and pooled into a random-effects meta-analysis using STATA software. The primary and secondary outcomes of the study were the pooled prevalence of RS and its morphological types, respectively. A total of 23 studies (n = 4,495 patients) were included. The overall pooled prevalence of RS was 83% (95% confidence interval [CI] [78, 87]). There were no significant differences in prevalence between cadaveric studies (82%, 95% CI [76, 87]) and laparoscopic studies (83%, 95% CI [77, 88]). The open RS constituted 66% (95% CI [61, 71]) of all cases, while the closed type was present in 34% (95% CI [29, 39]). RS is a relatively constant anatomical structure that can be reliably identified in most patients undergoing cholecystectomy. It can therefore be used as a fixed extra-biliary landmark for the appropriate site at which to start dissecting during LC to help prevent iatrogenic bile duct injury.

Sex variations in the structure of human atrioventricular annuli

Atrioventricular annuli are important in haemodynamic flexibility, competence, and support for tricuspid and mitral valves. The anatomical features of the annuli, such as circumference, organisation of connective tissue fibres, myocardium, and cellularity, may predispose to annular insufficiency and valvular incompetence. These pathologies occur more commonly in females, although the anatomical basis for this disparity is unclear. Sex variation in the structure of the annuli is important in providing a morphological basis for the patterns of these diseases. This study therefore aimed to determine the sex variations in the structure of human atrioventricular annuli. One hundred and one hearts (48 males, 53 females) obtained from the Department of Human Anatomy of the University of Nairobi were studied. Annular circumferences were measured using a flexible ruler and corrected for heart weight. Results were analysed using SPSS version 17.0 and sex differences determined using student's t-test. A p-value of less than 0.05 was considered significant. For light microscopy, specimens were harvested within 48 hours post-mortem, processed, sectioned, and stained with Masson's trichrome and Weigert's elastic stain with van Gieson counterstaining. Females had significantly larger annular circumferences than males after correcting for heart weight (p ≤ 0.05). Histologically, myocardium was consistently present in all male annuli while this was absent in females except in one specimen. The annuli were more elastic and cellular in males especially in the annulo-myocardial and annulo-valvular zones, respectively. The corrected larger annular circumference in females may limit heart valve coaptation during cardiac cycle and may be a risk factor for valvular insufficiency. The predominance of myocardium, annular cellularity, and elasticity may be more protective against heart valve incompetence in males than in females.