The Unusual High Origin Radial Artery in a Black Kenyan Population: A Cadaveric Study.

Background: The anatomy of the radial artery draws great interests among anatomists for its frequent involvement in variations. Equally, these variations have gained significant attention from clinicians because of the preference to use the radial artery for catheterization. The commonest of radial artery variations involve its site of origin. In published literature, data on this variations exist, but the prevalence of such variations in a Kenyan population has hitherto been unknown. Methods: Sixty-two upper limbs from 50 formalin-fixed cadavers were studied during dissection in the Department of Human Anatomy, University of Nairobi. Results: Fifty-four (87.1%) radial arteries arose within the cubital fossa, while eight (12.9%) had a high origin. Out of the eight high arteries, two (3.2%) branched off from the axillary artery, another two (3.2%) were branches of the proximal third of the brachial artery and four (6.5%) arose from the middle third of the brachial artery. The high origin radial arteries were more common on the right upper limbs (5 out of the 8 cases). Both axillary and brachial origins were seen bilaterally. Conclusion: The present study details important variations in the anatomy of the radial artery in a Kenyan population. With the radial artery being utilized during clinical, surgical and radiological interventions so frequently, an increased understanding and anticipation of such topographic variances is paramount.

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.

Prevalence and pubo-umbilical index of pyramidalis muscle in a select Kenyan population.

PURPOSE: Pyramidalis is a lower anterior abdominal wall muscle that is considered vestigial and shows variations in prevalence and size. It's been utilized as an anatomical landmark and harvested for use in various surgical procedures. Despite knowledge of its clinical importance, data on the prevalence of pyramidalis remain absent from the Kenyan population with few studies globally reporting on its pubo-umbilical index. We therefore aimed to determine the prevalence and relative lengths (pubo-umbilical index) of pyramidalis muscle in a sample Kenyan population. MATERIALS AND METHODS: Fifty-two cadavers (41 males, 11 females) from the Department of Human Anatomy, University of Nairobi were used. Prevalence and length of the muscle (l) were established, and the distance between pubic symphysis and umbilicus (L) measured and used to calculate pubo-umbilical index (l/L ×100%). Independent and paired T tests were done, using SPSS® version 22. A p value of ≤ 0.05 was considered statistically significant at a 95% confidence interval. RESULTS: Pyramidalis was present in 84% (44) of cadavers; 83% (43) bilaterally, 2% (1) unilaterally, and 85.4% (35) in males, 81.8% (9) in females. Mean length in males and females was 71.8 ± 35 mm and 63.5 ± 37.5 mm, respectively. Mean pubo-umbilical index was 38% ± 18 (39 % ± 18 males, 35% ± 19 females). No statistically significant difference was found. CONCLUSION: Pyramidalis is a highly prevalent muscle in the Kenyan population and, hence, could be exploited for its clinical and surgical utilities. The muscle terminates largely within the 2nd quarter (25-50%) of the infra-umbilical linea alba measured from pubic symphysis. Its pubo-umbilical index would be useful to surgeons making midline infra-umbilical incisions and performing procedures involving the muscle.

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.

Arterial Thrombosis in Coronavirus Disease 2019 Patients: A Rapid Systematic Review.

BACKGROUND: Emerging evidence suggests that severe form of coronavirus disease 2019 (COVID-19) is mediated, in part, by a hypercoagulable state characterized by micro- and macro-vascular thrombotic angiopathy. Although venous thrombotic events in COVID-19 patients have been well described, data on arterial thrombosis (AT) in these patients is still limited. We, therefore, conducted a rapid systematic review of current scientific literature to identify and consolidate evidence of AT in COVID-19 patients. METHODS: A systematic search of literature was conducted between November 1, 2019, and June 9, 2020, on PubMed and China National Knowledge Infrastructure to identify potentially eligible studies. RESULTS: A total of 27 studies (5 cohort, 5 case series, and 17 case reports) describing arterial thrombotic events in 90 COVID-19 patients were included. The pooled incidence of AT in severe/critically ill intensive care unit-admitted COVID-19 patients across the 5 cohort studies was 4.4% (95% confidence interval 2.8-6.4). Most of the patients were male, elderly, and had comorbidities. AT was symptomatic in >95% of these patients and involved multiple arteries in approximately 18% of patients. The anatomical distribution of arterial thrombotic events was wide, occurring in limb arteries (39%), cerebral arteries (24%), great vessels (aorta, common iliac, common carotid, and brachiocephalic trunk; 19%), coronary arteries (9%), and superior mesenteric artery (8%). The mortality rate in these patients is approximately 20%. CONCLUSIONS: AT occurs in approximately 4% of critically ill COVID-19 patients. It often presents symptomatically and can affect multiple arteries. Further investigation of the underlying mechanism of AT in COVID-19 would be needed to clarify possible therapeutic targets.

Cancer is associated with coronavirus disease (COVID-19) severity and mortality: A pooled analysis.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a rapidly escalating pandemic that has spread to many parts of the world. As such, there is urgent need to identify predictors of clinical severity in COVID-19 patients. This may be useful for early identification of patients who may require life-saving interventions. In this meta-analysis, we evaluated whether malignancies are associated with a significantly enhanced odds of COVID-19 severity and mortality. METHOD: A systematic search of literature was conducted between November 1, 2019, to May 26th, 2020 on PubMed and China National Knowledge Infrastructure (CNKI) to identify studies reporting data on cancers in patients with or without severe COVID-19 were included. The primary outcome of interest was the association between malignancies and COVID-19 severity, while the secondary outcome was the association between malignancies and COVID-19 mortality. Data were pooled into a meta-analysis to estimate pooled odds ratio (OR) with 95% confidence interval (95% CI) for either outcome. RESULTS: A total of 20 studies (n = 4549 patients) were included. Overall, malignancies were found to be associated with significantly increased odds of COVID-19 severity (OR = 2.17; 95% CI 1.47-3.196; p < 0.001) and mortality (OR = 2.39; 95% CI 1.18-4.85; p = 0.016). No heterogeneity was observed for both outcomes (Cochran's Q = 6.558, p = 0.922, I2 = 0% and Cochran's Q = 2.91, p = 0.71, I2 = 0% respectively). CONCLUSION: Malignancies were significantly associated with a 2-fold increase in the odds of developing severe COVID-19 disease, as well as mortality. Larger studies are needed to corroborate these findings. These patients should be closely monitored for any signs of unfavorable disease progression.

Acute Kidney Injury is Associated with Worse Prognosis In COVID-19 Patients: A Systematic Review and Meta-analysis.

BACKGROUND: The association between acute kidney injury (AKI) and outcome of coronavirus disease 2019 (COVID-19) has not yet been conclusively established. Therefore, we conducted a meta-analysis of recent scientific literature to assess whether AKI may be associated with worse prognosis and increased mortality in COVID-19 patients. METHODS: A systematic search of literature was conducted between 1st November 2019 and 15th May 2020 on Medline (PubMed interface) and China National Knowledge Infrastructure (CNKI) to identify potentially eligible studies. Cohort or case-control studies reporting data on AKI in patients with or without severe COVID-19 were included. Studies were divided into separate cohorts for analysis based on two endpoints (severity [severe vs non-severe] and mortality [non-survivors vs survivors]). Data were pooled into a meta-analysis to estimate pooled odds ratio (OR) with 95% confidence interval (95% CI) for either outcome. RESULTS: A total of 15 studies (n= 5,832 patients) were included in the analysis. Overall, AKI was found to be associated with significantly increased odds of COVID-19 severity (OR= 18.5; 95% CI 8.99-38.08) and mortality (OR= 23.9; 95% CI 18.84-30.31). No heterogeneity was observed for both outcomes (Cochran's Q= 6.21, p=0.52, I2=0% and Cochran's Q= 4.56, p=0.47, I2=0% respectively). -Conclusion: According to current data, AKI seems to be associated with worse prognosis in COVID-19 -patients. -Further investigation of the underlying mechanism of renal disease in COVID-19 would be needed to clarify possible therapeutic targets. AKI could be used as a clinical characteristic in severity classification and risk -stratification.

A meta-analysis of the relationship between anatomical variations of pulmonary veins and atrial fibrillation.

Background: Our aim was to provide an evidence-based assessment of the relationship between pulmonary vein variants and atrial fibrillation (AF).Methods: A comprehensive systematic search was performed on the databases PubMed, EMBASE, Cochrane library and Science Direct. Following assessment of eligibility and methodologic quality, data on PV variants were extracted and pooled into a meta-analysis.Results: A total of 12 studies (1337 cases and 1250 controls) were included. Presence of a right middle pulmonary vein was significantly associated with AF (OR = 1.85, 95% CI 1.26-2.72, p = .002). No significant association was however noted between presence of a common pulmonary vein ostia and AF. In the analysis of ostial diameters, the strongest association was observed between increased left common ostia diameter and AF (OR = 2.71, 95% CI 0.99-4.44, p = .002), followed by right superior (OR = 2.39, 95% CI 1.76-3.02, p < .00001), left superior (OR = 2.30, 95% CI 1.48-3.13, p < .00001), right inferior (OR = 2.19, 95% CI 1.69-2.69, p < .00001) and left inferior (OR = 1.79, 95% CI 1.25-2.34, p < .00001) pulmonary veins.Conclusion: The findings of the current study support the hypothesis that pulmonary vein variations predispose to AF. Further studies into the role of structural abnormalities of the pulmonary veins variations in the genesis of AF are recommended.

Surgical anatomy of the external branch of the superior laryngeal nerve: a systematic review and meta-analysis.

PURPOSE: To provide a comprehensive evidence-based assessment of the anatomical characteristics of the external branch of the superior laryngeal nerve (EBSLN). MATERIALS AND METHODS: A thorough systematic search was performed on the major electronic databases PubMed, EMBASE, Cochrane library, and ScienceDirect to identify eligible studies. Data were extracted and pooled into a meta-analysis. The primary outcomes were the EBSLN identification rate (total number of EBSLN identified divided by the total number of dissected hemilarynges) and the prevalence of various EBSLN types. RESULTS: A total of 56 studies (n = 13,444 hemilarynges) were included. The overall pooled EBSLN identification rate was 89.24% (95% CI 85.49-92.49). This rate was higher for cadaveric (95.00%; 95% CI 89.73-99.35) compared to that reported in intraoperative studies (86.99%; 95% CI 82.37-91.01). Significantly higher identification rates were reported for studies in which intraoperative nerve monitoring was used (95.90%; 95% CI 94.30-97.25) compared to those which only relied on direct visual identification of the EBSLN (76.56%; 95% CI 69.34-83.08). Overall, Cernea type IIa (nerves crossing the superior thyroid artery less than 1 cm above the upper edge of the superior thyroid pole) and Friedman type 1 (nerves running their entire course superficial to the inferior pharyngeal constrictor) were the most prevalent (41.84%; 95% CI 33.28-48.08 and 50%; 95% CI 29.90-65.62, respectively). The combined prevalence of Cernea IIa and IIb (nerves crossing the superior thyroid artery below the upper edge of the superior thyroid pole) was higher in intraoperative studies compared to that in cadaveric studies (64.3% vs 49.4%). The EBSLN coursed medial to the superior thyroid artery in 70.98% (95% CI 55.14-84.68) of all cases. CONCLUSION: The use of intraoperative nerve monitoring improves EBSLN identification rates. In light of the highly variable anatomical patterns displayed by the EBSLN, thorough pre-operative knowledge of its anatomy can be crucial in minimizing incidences of its iatrogenic injury.

Conventional and variant termination of the portal vein in a black Kenyan population.

BACKGROUND: Knowledge of the variant terminations of the portal vein is important in surgical and interventional radiological procedures of the liver. Their pattern and frequency are important in planning surgery to minimize complications. They differ between populations, but data from Africa is unavailable. AIM: To investigate the variant termination of the main portal vein. MATERIALS AND METHODS: One hundred livers from adult black Kenyans (age range 35 - 79 years) were studied at the Department of Human Anatomy, University of Nairobi, Kenya, by gross dissection. The livers were cleared of blood, fixed with 10% formaldehyde solution and the venous system infused with Acrylate monomers to keep the veins firm. The level of termination relative to the capsule and the branching pattern of the portal vein were examined. Various patterns were photographed using a digital camera. Data was analyzed using SPSS version 16.0 for windows and presented in tables and macrographs. RESULTS: Main portal vein termination was extracapsular in 14%, capsular in 40% and intrahepatic in 46%. Variant termination occurred in 49% of cases while conventional bifurcation occurred in 51% cases. Types, 2, 3 and 4 pattern of termination of main portal vein occurred in 15%, 22% and 12% cases respectively. The level of termination of the MPV had a positive correlation with its pattern (p=0.05). CONCLUSIONS: The high prevalence of variant termination of MPV in the current study suggests that the population is more vulnerable to inadvertent injury during surgery and radiological intervention. Besides, an extra hepatic termination of the MPV is more likely to have a conventional branching pattern compared to an intra-hepatic termination.