Comparison between the parietal foramina observed in samples of African and European population groups / Comparación entre los forámenes parietales observados en muestras de grupos de población africanos y europeos

SUMMARY: Parietal foramina of the human skull act as a passageway for emissary veins, connecting the superior sagittal sinus to the veins of the scalp. This passageway can lead to the spread of infection from the scalp to the dural venous sinuses, but may also assist in relieving intracranial pressure. However, variation in the prevalence of parietal foramina has been noted among population groups. This observational and descriptive study aimed to determine the incidence, size and location of parietal foramina by using osteological specimens of 252 African skulls from the Sefako Makgatho Health Sciences University, South Africa and 95 European skulls from the University of Leipzig, Germany. Parietal foramina were significantly more common in the African sample (61.9 %) compared to the European sample (55.8 %). Moreover, the Central European sample displayed more unilateral foramina (29.5 %), while the African sample exhibited more bilateral foramina (40.8 %). The diameter of the parietal foramen average 1.98 mm and 1.88 mm for the European and African samples, respectively. In this study, a median foramen on the sagittal suture was observed in 14 of the overall skull caps (4 %). This study demonstrated that parietal foramina are more prevalent than anticipated in both population groups. Findings of this study, indicating an increased prevalence, and the subsequent possibility of more emissary veins encountered, can be used to improve the understanding of the variations in the prevalence and clinical implications of the parietal foramen among various population groups located world-wide.

Los forámenes parietales del cráneo humano actúan como una vía para las venas emisarias, conectando el seno sagital superior con las venas del cuero cabelludo. Este pasaje puede conducir a la propagación de infecciones desde el epicráneo (calva) hasta los senos venosos durales, pero también puede ayudar a aliviar la presión intracraneal. Sin embargo, se ha observado una variación en la prevalencia de los forámenes parietales entre los grupos de población. Este estudio observacional y descriptivo tuvo como objetivo determinar la incidencia, el tamaño y la ubicación de los forámenes parietales mediante el uso de muestras osteológicas de 252 cráneos africanos de la Universidad de Ciencias de la Salud Sefako Makgatho, Sudáfrica, y 95 cráneos europeos de la Universidad de Leipzig, Alemania. Los forámenes parietales fueron significativamente más comunes en la muestra africana (61,9 %) en comparación con la muestra europea (55,8 %). Además, la muestra centroeuropea mostró más forámenes unilaterales (29,5 %), mientras que la muestra africana mostró más forámenes bilaterales (40,8 %). El diámetro del foramen parietal promedió 1,98 mm y 1,88 mm para las muestras europeas y africanas, respectivamente. En este estudio, se observó un foramen medio en la sutura sagital en 14 de los cráneos en general (4 %). El estudio demostró que los forámenes parietales son más frecuentes de lo previsto en ambos grupos de población. Los hallazgos de este estudio, que indican una mayor prevalencia y la subsiguiente posibilidad de que se encuentren más venas emisarias, pueden ser útiles para mejorar la comprensión de las variaciones en la prevalencia y las implicaciones clínicas del foramen parietal entre varios grupos de población ubicados en el mundo.

The dorsal nerve of the clitoris in relation to urinary incontinence sling procedures.

INTRODUCTION AND HYPOTHESIS: To avoid injury to the perineal branches of the pudendal nerve during urinary incontinence sling procedures, a thorough knowledge of the course of these nerve branches is essential. The dorsal nerve of the clitoris (DNC) may be at risk when performing the retropubic (tension-free vaginal tape) procedure as well as the inside-out and outside-in transobturator tape procedures. The purpose of this study was to identify the anatomical relationships of the DNC to the tapes placed during the procedures mentioned and to determine the influence of body variations. METHODS: In this cadaveric study, the body mass index (cBMI) of unembalmed cadavers was determined. Suburethral tape procedures were performed by a registered urologist and gynecologist on a sample of 15 female cadavers; six retropubic, seven inside-out and nine outside-in transobturator tapes were inserted. After embalmment, dissections were performed and the distances between the DNC and the tapes measured. RESULTS: In general the trajectory of the outside-in tape was closer to the DNC than that of the other tapes. cBMI was weakly and nonsignificantly correlated with the distance between the trajectory of the tape and the DNC for the inside-out tape and the tension-free vaginal tape, but not for the outside-in tape. CONCLUSIONS: The findings suggest that the DNC is less likely to be injured during the inside-out tape procedure than during the outside-in procedure, regardless of BMI. Future studies on larger samples are desirable to confirm these findings.

The Pudendal Nerve and Its Branches in Relation to Richter's Procedure.

OBJECTIVE: Variations in the branching pattern of the pudendal nerve (PN) have been described in the literature. This study investigated these variations in order to comment on a safe area for the placement of a Richter's stitch. METHODS: Richter's procedure was performed on nine unembalmed female cadavers and followed by dissection. PN dissections were done on another 20 embalmed female cadavers. Variations in the branching pattern of the PN were noted and the distance between the Richter's stitch placed and the PN/or the inferior rectal nerve (IRN) measured. RESULTS: The IRN entered the gluteal region as a separate structure in 6/29 cases. The separate IRN was found to pass between 4.1 and 14.45 mm medial to the ischial spine in 18/29 cases. In one case, the Richter's stitch was found to pierce the IRN. The distance between the stitch and the PN and/or the IRN ranged from 0 to 17.8 mm. CONCLUSIONS: To minimize the risk of nerve damage or entrapment, the Richter's stitch should be placed >20 mm from the ischial spine. This recommended area should be revised for different population groups, as variations might exist between groups.