Review of the anatomic concepts in relation to the retrorectal space and endopelvic fascia: Waldeyer's fascia and the rectosacral fascia

OBJECTIVE

A precise anatomical study of the fascias within the retrorectal space is reported, analyzing and clarifying the anatomical concepts previously employed to describe Waldeyer's and the rectosacral fascia.

METHOD

The pelvis was dissected in 15 cadavers (10 males and five females). All specimens were divided in the median sagittal plane including the middle axis of the anal canal, to allow a correct visualization of and access to the retrorectal space.

RESULTS

The retrorectal space was limited anteriorly by the rectum and posterior mesorectum covered by a fine visceral fascia, and posteriorly by the sacrum covered by the parietal presacral fascia. The rectosacral fascia divided the retrorectal space into inferior and superior portions in 80% of the male and 100% of the female specimens. It originated from the presacral parietal fascia at the level of S2 in 15%, S3 in 38% and S4 in 46% of specimens. In all cases it passed caudally to join the rectal visceral fascia 3-5 cm above the anorectal junction. As described by Waldeyer, the floor of the retrorectal space is formed by the fusion of the presacral parietal fascia and the rectal visceral fascia and lies above the levator ani muscle at the level of the anorectal junction.

CONCLUSION

The rectosacral fascia divides the retrorectal space into inferior and superior portions. This must be differentiated from Waldeyer's description of the fascia lying in the inferior limit of the retrorectal space, formed by the fusion of the rectal visceral and parietal fascias.

A photophase and seasonal study of the pineal parenchyma and melatonin serum levels in the albino rat subjected to immobilization stress

Sixty-four male Wistar rats (mean weight 215 +/- g) were divided into two groups of 32 animals each, with four additional subgroups (n = 8). The experimental group was subjected to immobilization stress for 24 hours and sacrificed during the photo - (10:00-14:00 hours) and scotophases (00:00-02:00 hours) of spring and winter. Photophase and seasonal differences were observed (p < 0.0001) between the corticomedullary karyometric values obtained in the control group. Similar results were obtained in the experimental group, though the seasonal differences were greater and favored spring (p < 0.0001), while the photophase differences were less important (p < 0.03). The number of synaptic ribbons showed a significant inversion of the physiological day/night ratio in both seasons. Similar results were obtained for the melatonin serum levels. The results suggest that photophase and season may be conditioning factors in the albino rat regarding pineal response to stress immobilization.

Endoscopic enhancement of the healing of high-risk colon anastomoses by low-power helium-neon laser. An experimental study

Recent studies suggest that helium-neon (He-Ne) lasers at low energy can enhance wound healing in intestinal anastomoses. In this experimental study, we tested the strength and collagen concentration of high-risk anastomoses of the rat colon after endoscopic irradiation by helium-neon laser. Our results show that repeated helium-neon laser irradiation (1.9 J/cm2) increases the bursting strength of the anastomoses by almost 100% on the fourth postoperative day. This effect is not observed by increasing the radiation dose (6.4 J/cm2). Differences in collagen (hydroxyproline) concentration did not reach statistical significance.

Stimulation of the healing of experimental colon anastomoses by low-power lasers

Anastomotic leakage following colorectal surgery remains a complication with high mortality and morbidity. Recent studies suggest that helium-neon (He-Ne) lasers at specific energy densities can be used to enhance wound healing in different tissues. In this experimental study we have tested the strength of end-to-end anastomosis of the rat colon irradiated by He-Ne laser by measuring bursting pressures and bursting wall tensions at 2, 4 and 7 days after operation. The study shows that He-Ne laser radiation induces a significant increase in colonic strength at the anastomosis. The laser does not cause the luminal narrowing observed in non-irradiated specimens.