Xenarthras: topografia intestinal e relações vasculares com a serosa / [Xenarthras: intestinal topography and vascular relationships with serosa]

Xenarthras (Mammalia, Dasypodidae) das espécies Dasypus novemcinctus e Euphractus sexcinctus tiveram sua anatomia científica estudada em relação à topografia dos intestinos delgado e grosso, suas relações peritoniais, morfologia externa e irrigação. Medidas dos diferentes segmentos intestinais e do número de vasos a eles destinados foram tomadas para fins comparativos. O método previu: fixação (formol 7%); injeção de látex; dissecação e fotodocumentação. Espacialmente, embora os intestinos sejam fixados por dupla membrana peritoneal, como em outros vertebrados, nestes a serosa conectou o duodeno, o jejuno, o íleo e os cólons em um único ligamento fixado no dorso do animal. Duodeno e pâncreas, intraperitoniais, como o reto, fixaram-se nas pelves maior e menor, respectivamente e dorsalmente. Vasos derivados do tronco celíaco mesentérico e da aorta percorreram o interior do mesoduodeno, do mesentério comum, do mesocólon e do mesorreto, estando estes, ao longo de seus trajetos, relacionados às cadeias linfonodulares intestinais. O modelo de rotação peritoneal, a morfologia externa, bem como o modelo de vascularização intestinal, foram interpretados como basais, diferindo dos vertebrados recentes, conforme o suporte literário.(AU)

Xenarthras (Mammalia, Dasypodidae) of the species Dasypus novemcinctus and Euphractus sexcinctus had their scientific anatomy studied in relation to the topography of the small and large intestines, their peritoneal relationships, external morphology and irrigation. Measurements of the different intestinal segments and the number of vessels destined for them were taken for comparative purposes. The method predicted: fixation (7% formaldehyde); latex injection; dissection and photo documentation. Spatially, the intestines, although fixed by a double peritoneal membrane, as in other vertebrates, in these, the serosa connected the duodenum, jejunum, ileum, and the colon in a single ligament fixed to the animal's back. Duodenum and pancreas, intraperitoneal, like the rectum, were fixed in the major and minor pelvis respectively and dorsally. Vessels derived from the mesenteric celiac trunk and the aorta traveled through the interior of the mesoduodenum, common mesentery, mesocolon and mesoride, being related to the lymph node chains along their pathways. The peritoneal rotation model, the external morphology as well as the model of intestinal vascularization were interpreted as basal, differing from recent vertebrates, according to literary support.(AU)

[Scientific interpretation of membrane anatomy theory and standardized application of membrane anatomy terms].

There has been an upsurge of the theory of membrane anatomy in China, but it is still in the initial stage of establishing preliminary framework. The concept of fasciae in membrane anatomy actually refers to the fasciae constituting the particular plane or the 'holy plane'. Therefore, the membrane anatomy can't simply be defined as the anatomical relationship among fascia. The application of the membrane anatomy is also not just to pursue the avascular plane in the surgical field. Nowadays, nonstandard anatomical terms and diversification of views impede the development of the theory of the membrane anatomy. Fasciae occur in embryonic stage, undergo a series of changes in rotation and fusion, and lose the original features, which bring difficulties in understanding the anatomy of fasciae. In this paper, we restore the origin and continuity of fasciae related to the colorectal surgery by cadaveric study, surgical observation and literature review. Taking the TME for example, we also discuss the core content about the fasciae and plane related to 'mesenteric envelope' and complete mesorectal excision. From the perspective of the fasciae integrity, we illustrate the definitions of important anatomical structure and standardized the terminology of fasciae. To study the origin and architecture of fasciae in the view of embryology, integrity and continuity will contribute to establish the standard theoretical system of membrane anatomy.

A new methodologic approach for clinico-pathologic correlations in invasive placenta previa accreta.

BACKGROUND: The development of new management strategies for women presenting with placenta accreta spectrum requires quality epidemiology data, which have so far been limited by the high variability in clinical and histopathologic data confirming the diagnosis at birth. OBJECTIVE: To evaluate the role of a new methodologic approach for the correlation of clinical and pathological data for women with a history of prior cesarean delivery diagnosed prenatally with placenta previa accreta. MATERIALS AND METHODS: A modified pathologic technique for gross examination of hysterectomy specimens with placenta in situ consisting of intraoperative examination, immediate postoperative examination, and guided histologic sampling was used prospectively in a cohort of 24 patients with singleton pregnancies complicated by placenta low-lying/placenta previa accreta. Maternal characteristics, detailed ultrasound findings, surgical outcomes, and histopathologic examination were compared with those of a group of 24 patients with similar clinical characteristics and in whom a standard pathologic examination method was used. RESULTS: The median reporting time for obtaining the complete histopathology results including the microscopic examination was significantly shorter (7 versus 15 days; P < .001) and the median number of samples taken for histologic examination significantly lower (4 versus 14 samples; P < .001) in the study group than in the controls. The number of histologic slides showing villous invasion was significantly higher (2 versus 1 slide; P = .002), and the ratio of the number of samples taken to the numbers of slides confirming villous invasion was significantly lower (2 versus 9; P < .001) in the study group than in the controls. In all cases in the study group, intraoperative examination identified a dense tangled bed of vessels or multiple vessels running laterally and cranio-caudally in the uterine serosa above the placental insertion that were no longer visible during immediate gross postoperative examination of the hysterectomy specimens. Immediate postoperative dissection enables the differential diagnosis between focal and large increta areas, and between abnormally adherent placenta and invasive placenta accreta. CONCLUSION: Valuable clinical information on the serosal vascularity, uterine dehiscence, and extension of the accreta area is added with the description of the macroscopic examination during the surgical procedure and immediate dissection of the specimen. This methodological approach is cost-effective and increases the quality of the histologic sampling. It thus provides more accurate correlations with the clinical data and more accurate epidemiologic data collection. Perinatal pathologists should be part of multidisciplinary teams involved the management placenta accreta spectrum disorders.

Embedment of the gastroduodenal artery stump into the jejunal serosa: A new technique aiming to prevent post-pancreatectomy hemorrhage.

Post-pancreaticoduodenectomy hemorrhage has an estimated incidence of 5% and a mortality rate of 11-38%. Vascular erosion resulting from pancreatic leak and skeletonization of the arterial wall during pancreatic mobilization may be the two possible mechanisms responsible for this complication, which most commonly affects the gastroduodenal artery stump. A novel technique of wrapping up the gastroduodenal artery stump into the jejunal serosa to decrease postoperative hemorrhage is presented.

Intestinal Mucosal and Serosal Microcirculation at the Planned Anastomosis during Abdominal Surgery.

INTRODUCTION: Intestinal blood flow is often named as a key factor in the pathophysiology of anastomotic leakage. The distribution between mucosal and serosal microperfusion during surgery remains to be elucidated. OBJECTIVE: The aim of this study was to assess if the mucosal microcirculation of the intestine is more vulnerable to a surgical hit than the serosal microcirculation during surgery. METHODS: In an observational cohort study (n = 9 patients), the microcirculation of the bowel serosa and mucosa was visualized with incident dark-field imaging during surgery. At the planned anastomosis, the following microcirculatory parameters were determined: microvascular flow index (MFI), percentage of perfused vessels (PPV), perfused vessel density (PVD), and total vessel density (TVD). Data are presented as median (interquartile range [IQR]). RESULTS: Perfusion parameters and vessel density were significantly higher for the mucosa than the serosal microcirculation at the planned site for anastomosis or stoma. Mucosal MFI was 3.00 (IQR 3.00-3.00) compared to a serosal MFI of 2.75 (IQR 2.21-2.94), p = 0.03. The PPV was 99% (IQR 98-100) versus 92% (IQR 66-94), p = 0.01. The TVD was 16.77 mm/mm2 (IQR 13.04-18.01) versus 10.42 mm/mm2 (IQR 9.36-11.81), p = 0.01, and the PVD was 15.44 mm/mm2 (IQR 13.04-17.78) versus 9.02 mm/mm2 (IQR 6.43-9.43), p = 0.01. CONCLUSIONS: The mucosal microcirculation was preserved, while lower perfusion of the serosa was found at the planned anastomosis or stoma during surgery. Further research is needed to link our observations to the clinically relevant endpoint of anastomotic leakage.

Can sidestream dark field (SDF) imaging identify subtle microvascular changes of the bowel during colorectal surgery?

BACKGROUND: Recognition of a non-viable bowel during colorectal surgery is a challenging task for surgeons. Identifying the turning point in serosal microcirculatory deterioration leading up to a non-viable bowel is crucial. The aim of the present study was to determine whether sidestream darkfield (SDF) imaging can detect subtle changes in serosal microcirculation of the sigmoid after vascular transection during colorectal surgery. METHODS: A prospective observational clinical study was performed at a single medical centre. All eligible participants underwent laparoscopic sigmoid resection and measurements were taken during the extra-abdominal phase. Microcirculation was measured at the transected bowel and 20 cm proximal to this point. Microcirculatory parameters such as Microvascular Flow Index (MFI), proportion of perfused vessels (PPV), perfused vessel density (PVD), total vessel density (TVD) and the Heterogeneity Index were determined. Data are presented as median (interquartile range) or mean ± standard deviation. RESULTS: A total of 60 SDF images were acquired for 10 patients. Perfusion parameters and perfused vessel density were significantly lower at the transected bowel compared with the non-transected measurements [MFI 2.29 (1.96-2.63) vs 2.96 (2.73-3.00), p = 0.007; PPV 74% (55-83) vs 94% (86-97), p = 0.007; and PVD 7.61 ± 2.99 mm/mm2 versus 10.67 ± 1.48 mm/mm2, p = 0.009]. Total vessel density was similar between the measurement locations. CONCLUSIONS: SDF imaging can identify changes of the bowel serosal microcirculation. Significantly lower serosal microcirculatory parameters of the vascular transected bowel was seen compared with the non-transected bowel. The ability of SDF imaging to detect subtle differences holds promise for future research on microvascular cut-off values leading to a non-viable bowel.

Effects of Thoracic Epidural Anaesthesia on the Serosal Microcirculation of the Human Small Intestine.

BACKGROUND: The effect of thoracic epidural analgesia (TEA) on splanchnic blood flow during abdominal surgery remains unclear. The purpose of this study was to examine whether the hemodynamic effects of TEA resulted in microcirculatory alterations to the intestinal serosa, which was visualized using incident dark-field (IDF) videomicroscopy. METHODS: An observational cohort study was performed. In 18 patients, the microcirculation of the intestinal serosa was visualized with IDF. Microcirculatory and hemodynamic measurements were performed prior to (T1) and after administering a bolus of levobupivacaine (T2). If correction of blood pressure was indicated, a third measurement was performed (T3). The following microcirculatory parameters were calculated: microvascular flow index, proportion of perfused vessels, perfused vessel density and total vessel density. Data are presented as median [IQR]. RESULTS: Mean arterial pressure decreased from 73 mmHg (68-83) at T1 to 63 mmHg (±11) at T2 (p = 0.001) with a systolic blood pressure of 114 mmHg (98-128) and 87 (81-97), respectively (p = 0.001). The microcirculatory parameters of the bowel serosa, however, were unaltered. In seven patients, blood pressure was corrected to baseline values from a MAP of 56 mmHg (55-57), while microcirculatory parameters remained constant. CONCLUSION: We examined the effects of TEA on the intestinal serosal microcirculation during abdominal surgery using IDF imaging for the first time in patients. Regardless of a marked decrease in hemodynamics, microcirculatory parameters of the bowel serosa were not significantly affected. TRIAL REGISTRY NUMBER: ClinicalTrials.gov identifier NCT02688946.

Use of an Image Acquisition Stabilizer Improves Sidestream Dark Field Imaging of the Serosa during Open Gastrointestinal Surgery.

AIM: To investigate whether an image acquisition stabilizer (IAS) mounted on the sidestream dark field camera (SDF) during gastrointestinal surgery improves image stability and acquisition. METHODS: Serosal SDF imaging was compared with SDF imaging combined with an IAS (SDF + IAS) during gastrointestinal surgery. Stability was assessed as the image drift in pixels and the time to obtain stable images. The success rate was determined as the percentage of analyzable images after recording. The effect of negative pressure from the IAS was determined during single-spot measurements and by comparing microvascular parameters between groups. Data are presented as mean ± SD. RESULTS: Sixty serosal measurements were performed per group; 87% were successful in the SDF group and 100% in the SDF + IAS group (p = 0.003). Image drift in the SDF group was 148 ± 36 versus 55 ± 15 pixels in the SDF + IAS group; p < 0.001. Time to stable image was 96 ± 60 s in the SDF group versus 57 ± 31 s in the SDF + IAS group; p = 0.03. No effect of negative pressure was seen. CONCLUSION: The use of an IAS mounted on an SDF camera during serosal microvascular assessment improves the success rate of image acquisition and stability and reduces the time to stable image with no effect on the microcirculation.

Surface microdialysis on small bowel serosa in monitoring of ischemia.

BACKGROUND: Ischemic injury of an organ causes metabolic change from aerobic to anaerobic metabolism. It has been shown in experimental studies on the heart and liver that such conversion may be detected by conventional microdialysis probes placed intra-parenchymatously, as well as on organ surfaces, by assaying lactate, pyruvate, glucose, and glycerol in dialysate. We developed a microdialysis probe (S-µD) intended for use solely on organ surfaces. The aim of this study was to assess whether the newly developed S-µD probe could be used for detection and monitoring of small bowel ischemia. METHODS: In anesthetized normoventilated pigs, a control S-µD probe was applied on the jejunal serosa 50 cm downstream from the duodenojejunal junction (DJJ). Starting 100 cm from DJJ, a 100-cm long ischemic segment was created by division of all mesenteric vessels. S-µDs were applied at 2.5, 5, 20, and 50 cm from the starting point of ischemia by serosal sutures. A standard µD probe was placed in the abdominal cavity as a further control. Dialysate was harvested before inducing ischemia and subsequently every 20 min for 4 h. Central venous blood was drawn every hour to monitor systemic lactate, C-reactive protein, and white blood cell count. RESULTS: Microdialysis lactate levels were significantly higher than baseline from 20 min on into protocol time in the ischemic segment and in the control S-µD probe. The peritoneal cavity probe showed no significant elevation. Lactate levels from the ischemic segment reached a plateau at 60 min. Courses of pyruvate, glucose, and glycerol levels were in accordance with transition from an aerobic to anaerobic metabolism in the bowel wall. No statistically significant changes in hemoglobin, white blood cell count, or lactate values in central venous blood were recorded. CONCLUSIONS: Assaying the aforementioned compounds in dialysate, harvested by the newly developed S-µD probe, allowed detection and monitoring of small bowel ischemia from 20 min on following its onset.

Sidestream dark field imaging of the serosal microcirculation during gastrointestinal surgery.

AIM: The study aimed to describe the serosal microcirculation of the human bowel using sidestream dark field imaging, a microscopic technique using polarized light to visualize erythrocytes through capillaries. We also compared its feasibility to the current practice of sublingual microcirculatory assessment. METHOD: In 17 patients sidestream dark field measurements were performed during gastrointestinal surgery. Microcirculatory parameters like microvascular flow index (MFI), proportion of perfused vessels (PPV), perfused vessel density (PVD) and total vessel density (TVD) were determined for every patient, sublingually and on the bowel serosa. RESULTS: Sixty measurements were done on the bowel of which eight (13%) were excluded, five owing to too much bowel peristalsis and three because of pressure artefacts. Image stability was in favour of sublingual measurements [pixel loss per image, bowel 145 (95% CI 126-164) vs sublingual 55 (95% CI 41-68); P < 0.001] and time to acquire a stable image [bowel 96 s (95% CI 63-129) vs. sublingual 46 s (95% CI 29-64); P = 0.013]. No difference in the MFI was observed [bowel 2.9 (interquartile range 2.87-2.95) vs sublingual 3.0 (interquartile range 2.91-3.0); P = 0.081]. There was a difference in the PPV [bowel 95% (95% CI 94-96) vs sublingual 97% (95% CI 97-99); P < 0.001], PVD [bowel 12.9 mm/mm2 (95% CI 11.1-14.8) vs sublingual 17.4 mm/mm2 (95% CI 15.6-19.1); P = 0.003] and the TVD [bowel 13.6 mm/mm2 (95% CI 11.6-15.6) vs sublingual 17.7 mm/mm2 (95% CI 16.0-19.4); P = 0.008]. CONCLUSION: Sidestream dark field imaging is a very promising technique for bowel microcirculatory visualization and assessment. It is comparable to sublingual assessment and the analysis produces a similar outcome with slightly differing anatomical features.

Noninvasive in vivo assessment of the skeletal muscle and small intestine serous surface microcirculation in rat: sidestream dark-field (SDF) imaging.

The pathophysiology of microcirculation is intensively investigated to understand disease development at the microscopic level. Orthogonal polarization spectral (OPS) imaging and its successor sidestream dark-field (SDF) imaging are relatively new noninvasive optical techniques allowing direct visualization of microcirculation in both clinical and experimental studies. The goal of this experimental study was to describe basic microcirculatory parameters of skeletal muscle and ileal serous surface microcirculation in the rat using SDF imaging and to standardize the technical aspects of the protocol. Interindividual variability in functional capillary density (FCD) and small vessels (<25 microm in diameter) proportion was determined in anesthetized rats on the surface of quadriceps femoris (m. rectus femoris and m. vastus medialis) and serous surface of ileum. Special custom made flexible arm was used to fix the SDF probe minimizing the pressure movement artifacts. Clear high contrast images were analyzed off-line. The mean FCD obtained from the surface of skeletal muscle and ileal serous surface was 219 (213-225 cm/cm(2)) and 290 (282-298 cm/cm(2)) respectively. There was no statistically significant difference between rats in mean values of FCD obtained from the muscle (P = 0.273) in contrast to ileal serous surface, where such difference was statistically significant (P = 0.036). No statistically significant differences in small vessels percentage was detected on either the muscle surface (P = 0.739) or on ileal serous surface (P = 0.659). Our study has shown that interindividual variability of basic microcirculatory parameters in rat skeletal muscle and ileum is acceptable when using SDF imaging technique according to a highly standardized protocol and with appropriate fixation device. SDF imaging represents promising technology for experimental and clinical studies.

[The effects of desensitization of capsaicin-sensitive neurons on the blood flow in microvessels of the rat gastric serous muscular membrane with normal and insufficient contents of glucocorticoids].

The effects of desensitization of capsaicin-sensitive neurons on the blood flow velocity in microvessels of the gastric muscular membrane were investigated before and after indomethacin (35 mg/kg) administration in adrenalectomized rats with or without corticosterone replacement (4 mg/kg sc) and in sham-operated animals. Desensitization of capsaicin-sensitive neurons was performed with neurotoxic dose of capsaicin (20 + 30 + 50 mg/kg sc) two weeks before the experiment. Adrenalectomy was created one week before the experiment. The in vivo microscopy technique for direct visualization of gastric microcirculation and analysis of red blood cell (RBC) velocity was employed. Indomethacin decreased the RBC velocity. Adrenalectomy by itself profoundly decreased the RBC velocity, whereas corticosterone replacement prevented this effect. Desensitization of capsaicin-sensitive neurons did not influence the RBC velocity in sham-adrenalectomized rats; however, it induced further fall of both basal and indomethacin-induced RBC velocity in adrenalectomized rats that was prevented by corticosterone. We conclude that glucocorticoid hormones have a beneficial effect on the blood flow velocity in microvessels of the gastric muscular membrane in rats with desensitization of capsaicin-sensitive neurons.

The role of laparoscopy in the diagnosis of intestinal vascular anomalies affecting two small infants.

Two infants affected by intestinal vascular anomalies causing lower gastrointestinal hemorrhage are reported. Upper and lower gastrointestinal tract endoscopy and radionuclide scan were negative. The authors found laparoscopic exploration very useful in detecting the cause and the site of bleeding. Because the usual investigations for gastrointestinal bleeding have been proven to be time-consuming and often unreliable in small infants, the authors suggest considering laparoscopic exploration as a first-line diagnostic tool in this subset of patients. A new diagnostic algorithm for gastrointestinal bleeding in infants is proposed.

Spontaneous haemoperitoneum secondary to a Meckel's diverticulum.

Meckel's diverticulum is a relatively common gastrointestinal entity which occasionally causes complications. Meckel's diverticulum is classically described to mimic acute appendicitis when inflamed as well as being a cause of unexplained luminal gastrointestinal bleeding. An unusual cause of spontaneous non traumatic haemoperitoneum found during surgery performed for a suspected acute appendicitis in a 22-year old female is described. The patient was found to have a significant haemoperitoneum due to a bleeding serosal vessel of a Meckel's diverticulum. The diverticulum was routinely excised. It was macroscopically and histologically devoid of inflammation. The bleeding vessel was not found to be abnormal or part of an arteriovenous malformation.

Spontaneous nontraumatic hemoperitoneum due to a bleeding arteriovenous malformation on the serosal surface of the transverse colon: a case report.

Arteriovenous malformations of the gastrointestinal tract are a very common entity and a frequently cited cause of lower gastrointestinal bleeding in adults. They are characteristically found in the mucosa or submucosa of the bowel wall, and the vast majority do not cause any symptoms. We discuss the rare case of an extraluminal arteriovenous malformation of the transverse colon in an elderly woman who presented to the emergency department in hypovolemic shock after collapsing at home. An exploratory laparotomy was performed after a diagnostic peritoneal lavage yielded gross blood. The patient was found to have a spontaneously bleeding lesion confined to the serosal surface of the right transverse colon, which histological examination revealed to be an arteriovenous malformation. The lesion was excised and the patient recovered without sequelae. To date there have been no other documented cases of an arteriovenous malformation on the serosal surface of a visceral abdominal organ.

[The reactivity of the links in the blood microcirculatory bed of the gallbladder in an experiment]. / Reaktivnost' zven'ev gemomikrotsirkuliatornogo rusla zhelchnogo rusla v éksperimente.

By means of TM-1 television capillaroscope morphofunctional changes of the gall bladder hemomicrocirculatory bed were studied in 40 male rabbits on the day 16 of starvation and 15 days after taking the animals on their normal ration. The data obtained demonstrated the stageness of reorganization of hemomicrocirculatory bed of serous coat of the gall bladder and indicated its high mobility and significant resistance, thus confirming the possibility of correction in exerting influence upon the organism.

Reduction in tissue blood flow in J-shaped pelvic ileal reservoirs.

PURPOSE: This study sought to evaluate tissue blood flow during J-shaped ileal reservoir construction. METHODS: Using laser Doppler flowmetry, tissue blood flow was measured at various locations in J-shaped ileal reservoirs constructed in 10 dogs before pouch-anal anastomosis. For 12 weeks postoperatively, animals were assessed for clinical complications. In another five dogs, tissue blood flow was measured at various stages of J-pouch construction. RESULTS: Tissue blood flow in the reservoir was reduced and was lowest at the "apex" of the "J", the site of clinical stricture in one animal. During reservoir construction, longitudinal enterotomy was associated with the greatest reduction in tissue blood flow. Lowest blood flow in the reservoir was at the site of the intended pouch-anal anastomosis (11.5 +/- 1.6 ml/100 g/min vs. 43.4 +/- 3.4 ml/100 g/min (controls); P < 0.05). CONCLUSIONS: Operative maneuvers of J-shaped ileal reservoir construction, particularly longitudinal enterotomy, significantly reduce tissue perfusion in the involved bowel segment. Tissue blood flow in the pouch is lowest at the site of intended pouch-anal anastomosis, and this may contribute to development of complications seen clinically.

[Relationship between venous invasion and hematogenous metastasis in the gastric cancer].

We investigated the correlation between venous invasion and hematogenous metastasis in gastric cancer. In 70 patients with gastric cancer, 8 cases had hepatic metastasis at operation (group A), 26 cases were identified with hematogenous recurrence after operation (group B) and 36 cases were disease free over 5 years after operation (group C). Specimens were all step-sectioned and serial sections were stained both with HE and EM. Rates of venous invasion were calculated as following formulae; (number of cancer involving veins/total number of veins investigated) x 100 (%). Results were as follows. 1. Average rates of venous invasion (ARVI) of groups A and B were significantly higher than that of group C (A; 7.6%, B; 2.6%, C; 0.7% p < 0.05). 2. In subserosal or serosal layer, there is no significant difference between ARVI of group A and that of group B. 3. No significant difference was seen between group A and B in rates of venous invasion to larger vein (diameter > 200 microns). These observations suggest that cancer invasion to the veins located in deeper than subserosal layer or ranged in diameter over 200 microns relates to hematogenous metastasis.