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Cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC) is a complex procedure that often requires ostomy creation to protect high-risk anastomoses. This study aimed to evaluate the authors’ institutional experience with CRS-HIPEC-associated ostomies, determine predictors of ostomy creation and reversal, and assess their impact on survival. The study analyzed clinicopathologic, perioperative, and oncologic data from a prospective database of 1435 CRS-HIPEC procedures for peritoneal metastases. The Kaplan–Meier method was used to estimate survival. Multivariate analyses identified associations with ostomy creation/reversal and survival. Ostomies were created in 34% of the patients, most commonly loop ileostomies (82%). Loop ileostomies were reversed in the majority of patients (83%), whereas non-loop ileostomies were infrequently reversed (

The purpose of this paper was to perform a bibliometric analysis of the production of qualitative research in scientific journals through aggregation by levels and to identify factors of diversity, such as types of designs, in qualitative research on the experience of having an intestinal stoma between 2002 and 2018.Descriptive bibliometric study focused on the production of qualitative research on the subject of study, on three levels: micro, meso and macro.Databases such as PubMed, CINAHL, Web of Knowledge, Scopus, SciELO, CUIDEN, Lilacs and Google Scholar were used to collect the data, between August - November 2018.Nursing was the main area of knowledge. Brazil was the predominant country of origin. The most productive journal was the Journal of Wound, OstomyContinence Nursing. English and Portuguese were the main languages of scientific communication. The number of authors was typically between 2 and 6. Authors conducted descriptive and phenomenological studies.The present bibliometric study helps us to map the qualitative research on the experiences of individuals with an intestinal stoma and to understand patterns in the designs, methods, disciplines and journals involved in this area of research. This will allow nurses to have a leading contribution to stoma care at their disposal.目的: 本文旨在通过分级汇总对科学期刊定性研究成果进行文献计量分析,从而确定2002年到2018年期间发表的有关肠造口术后患者的定性研究中设计类型等多样性因素。 设计: 描述性文献计量研究侧重于在微观、中观和宏观三个层面上对研究对象展开定性研究。 方法: 通过PubMed、CINAHL、Web of Knowledge、Scopus、SciELO、CUIDEN、Lilacs和谷歌学术搜索等数据库对2018年8月至11月间发表的文献数据进行检索。 结果: 护理是一大主要知识领域。巴西是主要来源国。最有成效的期刊为《创面、造口及自制护理杂志》。英语和葡萄牙语是科学交流的两大主要用语。作者人数通常在2到6人之间。作者还开展了描述性和现象学研究。 结论: 当前的文献计量研究有助于我们对肠造口术后患者展开定性研究,了解这一研究领域所涉及的设计、方法、学科和期刊模式。这将使护士在造口护理方面发挥主导作用。.

Purpose The objective of this study was to examine relationships among social interaction, health utility, and peristomal skin status in adults with ostomies. Design Cross-sectional, descriptive. Subjects and setting 15,591 persons residing in the United States were randomly selected from 3 multinational proprietary databases of individuals who had undergone surgery. Methods The study was a cross-sectional assessment utilizing the SF36v2 survey instrument. Potential subjects were sent an e-mail letter of invitation that included instructions for completing the questionnaire, an informed consent form, and nontransferable link to an electronic survey. Health utility was derived from the SF6D, and the Hawthorne Friendship Scale was used to measure social connectivity. Social functioning was derived from the SF36v2. A minimally important social value of health (MISVH) is reported as the minimum quality-adjusted life-days to be of benefit (influence) within indices of social connectivity and function. A self-reported determinant of peristomal skin health was included. Results Increased social interactivity, defined as social functioning and social connectivity, was associated with increased health utility. In addition, health utility decreased as peristomal skin integrity worsened. A MISVH can be demonstrated. Conclusion Findings indicate that peristomal skin complications are more than dermatologic issues. They negatively affect the well-being of those who must cope and adapt to their impact and the community at large. Social interaction is also negatively influenced.

Peristomal skin problems represent one of the most common complications of a tracheostomy. A quasi-experimental study was conducted among patients ages 18 to 65 years hospitalized in a Turkish university hospital ear-nose-throat clinic between August 15, 2013, and December 15, 2013, to compare the effect of using or not using a barrier cream on the peristomal skin with regard to pH, moisture, temperature, color, odor, turgor, infections, and lesions after tracheostomy surgery. Patients were selected using a purposeful sampling method and included if they had not undergone another operation for a complication (eg, pneumothorax, tube misplacement, hemorrhage) within 24 hours following the tracheostomy operation. In phase 1 of the study, 9 registered nurses were observed 3 times each by the researcher, who completed an observation form. From these observations and related nursing textbooks, the researcher developed a protocol entitled "Nursing Care Steps for Patients with a Tracheostomy." This protocol was followed during phase 2 of the study during which participants were alternately assigned to either the intervention (a barrier cream containing dimethicone, acrylate terpolymer, oils, paraffin, water, dicapryladipate, isopropyl palmitate, and PPG-15 stearyl ether followed by gauze) or control (gauze only) group (n = 30 each) and observed for 7 days. Demographic characteristics were gathered for each patient upon admission to the study. Peristomal skin was assessed in terms of pH, temperature, and moisture (relative humidity [RH]) using a surface pH meter, surface thermometer, and digital skin moisture tester, as well as for lesions, infection, and maceration. Findings were documented on a skin condition assessment form. Twenty-four (24) hours post surgery, the barrier cream plus gauze was applied over peristomal area in the study group and gauze dressing only in the control group. Peristomal skin pH, moisture, and temperature were within the normal range for both groups during all observations throughout the study but closer to normal ranges in the intervention group. Mean peristomal skin pH in the intervention group was significantly higher (5.452 ± 0.043) than in the control group (5.123 ± 0.057; P &.001), mean peristomal skin moisture in the control group (46.90 ± 0.132 RH) was significantly greater than in the intervention group (41.71 ± 0.774 RH; P &.001), and mean peristomal skin temperature in the control group (33.59 ± 1.3˚ C) was significantly higher than in the intervention group (31.64 ± 0.607˚ C; P &.001). In both groups, Staphylococcus epidermidis was the most commonly cultured microorganism, and S aureus was the most cultured pathological microorganism in addition to the normal skin flora. Peristomal skin condition was maintained for both the intervention and control groups. Use of a barrier cream to protect tracheostomy peristomal skin beneath absorbent dressings (eg, gauze) is recommended, but additional short-term and long-term studies are needed.

Cytoreductive surgery with heated intraperitoneal chemotherapy (CRS/HIPEC) often includes stoma creation. We evaluated the indications, morbidity, and mortality associated with stoma creation and reversal after CRS/HIPEC. Retrospective analysis of a prospective database of 1149 CRS–HIPEC procedures was performed. Patient demographics, type of malignancy, comorbidities, Clavien-graded morbidity, mortality, indications for stoma creation, and outcomes of subsequent reversal were abstracted. Sixteen percent (186/1149) of CRS/HIPEC procedures included stoma creation, whereas 1.1 % (11/963) of patients without initial stoma creation developed anastomotic leaks requiring stoma. Patients who required a stoma had worse preoperative performance status (ECOG 0/1: 77.2 vs. 86.1 %, p = 0.002), greater burden of disease (PCI 17.6 vs. 12.9, p

Lymphatic stomata are small lymphatic openings in the serosal membrane that communicate with the serosal cavity. Although these stomata have primarily been studied in experimental mammals, little is known concerning the presence and properties of lymphatic stomata in the adult human pleura. Thus, adult human pleurae were examined for the presence or absence of lymphatic stomata.A total of 26 pulmonary ligaments (13 left and 13 right) were obtained from 15 adult human autopsy cases and examined using electron and light microscopy. The microscopic studies revealed the presence of apertures fringed with D2-40-positive, CD31-positive, and cytokeratin-negative endothelial cells directly communicating with submesothelial lymphatics in all of the pulmonary ligaments. The apertures' sizes and densities varied from case to case according to the serial tissue section. The medians of these aperture sizes ranged from 2.25 to 8.75 μm in the left pulmonary ligaments and from 2.50 to 12.50 μm in the right pulmonary ligaments. The densities of the apertures ranged from 2 to 9 per mm(2) in the left pulmonary ligaments and from 2 to 18 per mm(2) in the right pulmonary ligaments. However, no significant differences were found regarding the aperture size (p=0.359) and density (p=0.438) between the left and the right pulmonary ligaments.Our study revealed that apertures exhibit structural adequacy as lymphatic stomata on the surface of the pulmonary ligament, thereby providing evidence that lymphatic stomata are present in the adult human pleura.

Lymphatic stomata are small openings of lymphatic capillaries on the surface of the mesothelium that lines the serous cavity and have the function of active absorption. They play an important role in physiological and pathological conditions. The cavity of the tunica vaginalis is a typical serous cavity of the testis, but the lymphatic stomata of the tunica vaginalis of humans have never been reported. Here, we studied their ultrastructure by scanning and transmission electron microscopy. The submesothelial connective tissue with foramina was investigated after the mesothelial cells were digested using NaOH solution. We found the lymphatic stomata in cuboidal mesothelial cell regions of the parietal layer of the tunica vaginalis of humans with a diameter of about 1–2 μm. Sometimes, closed lymphatic stomata could be observed. Our study is the first to report the existence of lymphatic stomata of the tunica vaginalis of humans. We found that the tunica vaginalis cavity is connected with the lymphatic system through the stomata, which might provide a morphological basis for the drainage of hydrocele and tumor metastasis of the tunica vaginalis of humans.

The contribution of lymphatic drainage through the stomata of parietal mesothelium to the overall removal of labeled albumin from the pleural space was found 89% in sheep with very large hydrothoraces (10 ml/kg), a condition involving a approximately 20 times increase in lymphatic drainage [Broaddus et al., J. Appl. Physiol. 64 (1988) 384]. We determined this contribution in anesthetized rabbits with small (0.12 ml/kg) and large (2.4 ml/kg) hydrothoraces of Ringer-albumin with labeled albumin and labeled dextran-2000 kDa. This dextran was used as marker of liquid removal through the stomata because it should essentially leave the pleural space through the stomata only, owing to its size. The removal of labeled albumin by lymphatic drainage through the stomata was 39% of the overall removal in the small hydrothoraces, and 64% in the large ones. Hence, lymphatic drainage through the stomata does not contribute most of protein and liquid removal from the pleural space under physiological conditions, as it has been maintained. It markedly increases with the increase in pleural liquid volume.

Numerous investigations concerning the fine morphology of diaphragmatic stomata have been performed, but its ultrastructural changes in experimental conditions remain unclear. The present study demonstrates the peritoneal side of the diaphragm in adult Wistar rats by transmission electron microscopy. Ten experimental animals were observed 5 and 8 days after Pseudomonas aeuriginosa instillation (PI) into the peritoneal cavity. A control group of 6 rats showed flat mesothelial covering on basal lamina (BL) and connective tissue layer, as well as cubic mesothelial cells, single stomata over underlying lymphatic lacunae (LL). Five days after PI the mesothelial cells had more numerous microvilli, microvesicles, vacuoles, lysosomes and a lesser number of specialized contacts. The multiplication of the extravasal cells and larger intercellular spaces lead to thickenings of the connective tissue around LL. LL were larger and located in close proximity of the mesothelium. Intercellular spaces in the mesothelial layer and different types of contacts between mesothelial cells and endothelial protrusions of LL (with common BL or without BL) were encountered. Eight days after PI the mesothelium, endothelium of LL, their BL and surrounding connective tissue were interrupted and structurally modified to form typical new channels--stomata. The larger portion of the channels were formed of mesothelial cells, while the endothelial cells participated in the submesothelial part. LL were more numerous than in the previous period, and were arranged in groups. LL increased their vertical (50.59 microm) and horizontal (155.57 microm) diameter, as compared with control animals (respectively 12.37 microm and 74.08 microm). Neighbouring LL were separated by thin or thick septae. Peristomatal mesothelial cells or more rarely endothelium formed valve- or bridge-like structures. Valves on the opposite side of LL were observed. Groups of electron-dense bodies characterized some tall endothelial cells of LL. Cubic mesothelium, endothelium of the LL, both BL, the cell connections that formed new stomata, LL and surrounding connective tissue underwent rapid and parallel changes after PI. Among these elements of the lymphatic regions mentioned above, the mesothelium and endothelium of LL had a main role in experimental conditions.

The peritoneal stomata, lymphatic drainage units and subperitoneal terminal lymphatics, called lymphatic lacunae, form a specialized drainage system in the diaphragm, by which absorption of fluid in bulk, particles and cells is carried out in the peritoneal cavity. The aim of this study is to elucidate the three-dimensional organization and function of the subperitoneal lymphatic lacunae and lymphatic drainage units by using lymphatic casts in the scanning electron microscope (SEM), ODO (OsO4-DMSO-OsO4) freeze fracture, conventional SEM and the transmission electron microscope (TEM). The subperitoneal lymphatic lacuna is unique for its large size and its multiple morphology and can be recognized by its broad, flattened enlargement and the blind-ends of lymphatic vessels, from which extend numerous main lymphatic vessels and side branches. These lymphatic vessels communicate with each other and form a rich lymphatic plexus under the diaphragmatic peritoneum. Two layers of lymphatic networks, i.e. the subperitoneal plexus and the deeper plexus are found in the muscular portion. Only one layer is present in the tendinous portion of the human diaphragm. The lymphatic plexus is denser in the tendinous portion than that in the muscular portion. The lymphatic lacunae occur exclusively in the muscular portion of the human diaphragm. The lumina of lymphatic lacunae are separated from the peritoneal cavity by a barrier consisting of cuboidal mesothelial cells, endothelial cells of the lymphatic lacunae and intervening connective tissue forming a lymphatic drainage unit. All these three components of the lymphatic drainage unit abut upon each other, but are not linked by specialized junctions. The cuboidal mesothelial cells frequently extend valve-like cytoplasmic processes that bridge the subperitoneal channel and make give it a tortuous course. The fibrous layer of the connective tissue is arranged in fiber bundles and gives a three-dimensional network forming the floor of the peritoneal stomata and the roof of the lymphatic lacunae. Via the fibrous network, the cuboidal mesothelial cells and the endothelial cells of the lacunae come into close contact with each other and form short subperitoneal channels which connect the peritoneal cavity with the subperitoneal lymphatic lacunae. The lymphatic drainage units may regulate the material absorption of the peritoneal stomata from the peritoneal cavity. It is suggested that the peritoneal stomata together with the subperitoneal channels, lymphatic drainage units and lymphatic lacunae comprise an important diaphragmatic lymphatic drainage system which plays an important role in the absorption of materials from the peritoneal cavity.

In 15 rats the morphology and distribution of stomata and mesothelial cells of the diaphragm and of different serosal areas were studied by light and electron microscopy. Cell surface patterns, identified by SEM, varied according to location. Mesothelial cells of the diaphragmatic peritoneum were either cuboidal or flattened. Stomata were found only among cuboidal cells and were consistently and exclusively observed on the muscular part of the diaphragm, predominantly on the peritoneal surface. Stomata appeared oval or rounded, 4–10 μm in diameter. When India ink was introduced into the peritoneal cavity as a tracer, carbon particles were rapidly removed through stomata into the subjacent lymphatic lacunae of the diaphragm. Mesothelium overlying the diaphragm differed morphologically from that over the remaining peritoneal and pleural cavities. Mesothelium of the latter formed a continuous sheet of flattened cells whose surfaces were studded with numerous microvilli. Stomata were absent. It is suggested that stomata are exclusive to the diaphragm and may serve as the main drainage channels for fluid and particles from the peritoneal cavity. This has important clinical implications. Thus stomata could represent a liability by providing a route for the escape of tumor cells and pathogens from the peritoneal cavity. However, they may represent an asset by providing an accessible route for blood transfusion and for peritoneal dialysis in treating chronic renal failure. © 1994 Wiley-Liss, Inc.

A morphological study of the lymphatic system in the diaphragm of adult Japanese monkeys was carried out using intraperitoneal injection with India ink, light microscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) techniques. For SEM examination of the subperitoneal connective tissue, the peritoneal mesothelium was stripped by either the NaOH/sonication microdissection techniques or the NaOH digestion method. Light microscopy of 1 micron Epon sections and TEM of thin sections demonstrated that lymphatic capillaries were distributed in the subperitoneal connective tissue of the muscular and tendinous portions. Gaps (stomata) between neighboring cells of the peritoneal mesothelium were occasionally encountered. In SEM observations, stomata with oval shapes and various sizes were abundantly seen in the peritoneal mesothelium, but were absent from the pleural mesothelium. It deserves particular note that a large number of foramina were detected in the subperitoneal connective tissue. The cluster of the foramina was similar in appearance to the "macula cribriformis" depicted by KIHARA (1956). Carbon particles injected into the monkey peritoneal cavity passed through the peritoneal stomata and then the macula cribriformis, ultimately to enter the lymphatic capillaries. This paper also discusses the functional implication of the lymphatic system in the diaphragm.

Lymphatic stomata are small openings of lymphatic capillaries on the free surface of the mesothelium. The peritoneal cavity, pleural cavity, and pericardial cavity are connected with lymphatic system via these small openings, which have the function of active absorption. The ultrastructure of the lymphatic stomata and their absorption from the body cavities are important clinically, such as ascites elimination, neoplasm metastasis, and inflammatory reaction. The lymphatic stomata play an important role in the physiological and pathological conditions. Our previous study indicated for the first time that nitric oxide (NO) could regulate the opening and absorption of the lymphatic stomata. It could decrease the level of free intracellular calcium [Ca(2+)] through increasing the cyclic guanosine monophosphate (cGMP) level in the rat peritoneal mesothelial cells, thus regulating the lymphatic stomata. This process is related with the NO-cGMP-[Ca(2+)] signal pathway. In this review, we summarize the recent advances in understanding the development and the function of the lymphatic stomata. The ultrastructure and regulations of the lymphatic stomata are also discussed in this review.

In 16 human specimens the topography and organization of stomata and mèsothelial cells of the diaphragmatic, pelvic wall and anterior abdominal wall peritoneum were studied by transmission electron microscopy, scanning electron microscopy and the image processing technique. The mesothelial cells were organized into two discrete populations, cuboidal cells and flattened cells. The stomata were found only among cuboidal cells, either on the muscular portion or on the tendinous portion of the diaphragm. The size and shape of stomata, which were arranged in a cluster or a strip were often irregular. The average area of a stoma on the muscular portion was 10.43 ± 1.61 µm2 on the tendinous portion 7.93 ± 1.67 µm2. Stomata opened to submesothelial connective tissue, under which numerous lymphatics were observed. Stomata were not discovered in the pelvic and anterior abdominal wall peritoneum. In animal experiments intraperitoneally injected trypan blue particles were rapidly removed from the peritoneal cavity through stomata of the diaphragmatic peritoneum in rabbits. It is suggested that stomata may be the main pathway for draining matter from the peritoneal cavity and that the diaphragmatic peritoneum shows the strongest absorption in all parts of the peritoneum.

We have previously demonstrated that nitric oxide (NO) is involved in the regulation of the lymphatic stomata. However, the related mechanisms are still unknown. The present study was designed to test the hypothesis that NO-cyclic guanosine monophosphate (cGMP) -mediated cytosolic Ca(2+) concentration ([Ca(2+)]i) signaling may contribute to the regulation of the lymphatic stomata and lymph drainage. Using trypan blue as a tracer, the effects of NO-cGMP-Ca(2+) signal cascade on the lymphatic stomata and lymph absorption were examined by means of scanning electron microscopy. Then, the role of NO in cGMP and [Ca(2+)]i of rat peritoneal mesothelial cells (RPMCs) was measured by radioimmunoassay and a confocal laser scanning microscope. Our results showed that NO-donor spermine/nitric oxide complex (Sper/NO) could broaden the opening area of the lymphatic stomata and enhance lymph absorption in a dose-dependent manner. These NO-mediated changes could be blocked by 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ), a specific inhibitor of soluble guanylyl cyclase, and mimicked by calcium channel blocker nifedipine. Furthermore, Sper/NO enhanced the cGMP level and lessened [Ca(2+)](i) in RPMCs, which was completely abrogated at the presence of ODQ. Nifedipine induced an immediate and marked decrease of [Ca(2+)](i) in the RPMCs, which was not attenuated by addition of Sper/NO, indicating that the Sper/NO-cGMP signaling system induced [Ca(2+)](i) change was related to the L-type voltage-gated calcium channel in the RPMCs. Our results suggest that NO enlarges the opening area of the lymphatic stomata to strengthen the lymph drainage of tracer by means of NO-cGMP-[Ca(2+)]i signal transduction pathway in the RPMCs.

To study the cell signal transduction mechanism of nitric oxide (NO) on the peritoneal lymphatic stomata and lymph drainage in the rat, cGMP content were measured by a commercially available radioimmunoassay kit, and the [Ca(2+)](i) were observed by a confocal laser scanning microscope in the cultured peritoneal mesothelial cell. Animal experiment was practiced to study the effect of NO-cGMP-Ca(2+) pathway on the lymphatic stomata and lymph absorption. The results showed that: (1) Sper/NO increased cGMP of the rat peritoneal mesothelial cell (RPMC) in a dose-dependent manner (P0.01) compared to the control group. This effect was blocked by 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ) (P0.05), a specific inhibitor of soluble guanylyl cyclase (sGC). The level of [Ca(2+)](i) in single RPMC decreased by adding Sper/NO (P0.05). Pretreatment with ODQ for 10 min blocked the Sper/NO-induced decrease in [Ca(2+)](i). L-typed calcium channel blocker nifedipine induced an immediate and marked decrease in [Ca(2+)](i) (P0.05).. After [Ca(2+)](i) reached a balance again, adding Sper/NO could not change [Ca(2+)](i) (P0.05). (2) Sper/NO increased the area of the stomata (P0.01) and the quantity of the tracer in a dose-dependent manner (P0.05) compared to the control group. Pretreatment with ODQ significantly inhibited Sper/NO-induced change of lymphatic stomata and lymph drainage (P0.01). Nifedipine increased the opening area of the lymphatic stomata (P0.01) and the concentration of absorbed trypan blue of the diaphragm (P0.05). Sper/NO could not make a further change in the samples pretreated by nifedipine (P0.05). The results indicate that NO can decrease [Ca(2+)](i) in the RPMC through the NO-cGMP pathway. This procession is related with the L- type voltage-gated Ca(2+) channel. NO enlarges the opening area of the lymphatic stomata and enhances the lymph drainage of tracer by NO-cGMP-[Ca(2+)](i) pathway.

Summary The visceral peritoneum of intraabdominal organs (spleen, stomach, liver, small intestine), omentum majus and the parietal peritoneum of the anterior abdominal wall and the diaphragm were studied in adult Wistar rats by combined scanning and transmission electron microscopy (SEM, TEM). In general, the peritoneal surface consisted of a mesothelium composed of cubic, flat or intermediate cell types delimited by a basal lamina. Cubic mesothelial cells predominated in parenchymal organs (spleen, liver) and were characterized by prominent and indentated nuclei, a cytoplasm richly supplied with organelles, a dense microvillous coat, basal invaginations and elaborate intercellular contacts. Flat mesothelial cells were observed in the intestinal, omental and parietal peritoneum (tendinous diaphragm, abdominal wall) and showed elongated nuclei, scant cytoplasm, a poorly developed organelle apparatus and sparsely distributed microvilli. An intermediate mesothelial cell type was described within the gastric peritoneum characterized by a central cytoplasmic protrusion at the nuclear region containing most of the cytoplasmic organelles and by thin finger-like cytoplasmic processes. The submesothelial connective tissue layer was composed of collagen fiber bundles, fibroblasts and free cells (macrophages, granulocytes, mast cells) and contained blood and lymphatic vessels. In the spleen, elastic fibers formed a membranous structure with intercalated smooth muscle cells. Mesothelial openings were observed as tunnel-like invaginations within the hepatic peritoneum and as clusters of peritoneal stomata within the parietal peritoneum of the anterior abdominal wall and the muscular diaphragm. The round or oval openings of the peritoneal stomata were frequently occluded by overlapping adjacent mesothelial cells and their microvillous coat or obstructed by cellular material. At the side of the peritoneal stomata the mesothelial cell layer was interrupted to allow a direct access to the underlying submesothelial lymphatic system. The mesothelium and lymphatic endothelium shared a common basal lamina. The endothelial cells were discontinuous and displayed valve-like plasmalemmatic interdigitations facilitating an intercellular transport of fluids and corpuscular elements from the peritoneal cavity to the submesothelial lymphatic lacunae. The findings underline the morphological heterogeneity of the peritoneum in visceral and parietal regions, suggesting different functional implications, and further support the presence of extra-diaphragmatic peritoneal stomata.

Peritoneal stomata constitute the principal pathways for the drainage of intraperitoneal contents from the peritoneal cavity to the lymphatic system and have been claimed to be exclusively restricted to the peritoneal surface of the diaphragm. This concept has been revised by the demonstration of peritoneal stomata in the omental, mesenteric, ovaric and pelvic peritoneum. Therefore, the aim of this study was to further assess peritoneal surfaces of several other abdominal organs and of the abdominal wall with special reference to the occurrence of peritoneal stomata. The peritoneum covering the spleen, stomach, intestine, liver, diaphragm and anterior abdominal wall obtained from rats was examined by scanning electron microscopy. Whereas the splenic and hepatic peritoneal surfaces were composed of uniformly distributed cuboidal mesothelial cells, the gastric and intestinal peritoneal surfaces were arranged in parallel folds composed of prominent mesothelial cells with elongated finger-like cytoplasmic processes. In addition to diaphragmatic peritoneal stomata, mesothelial openings were also found on the peritoneal surfaces covering the anterior abdominal wall and the liver. The parietal peritoneal stomata were arranged in clusters, oval in shape and delimited by flattened mesothelial cells exposing the underlying submesothelial connective tissue. The hepatic mesothelial openings formed by deep channel-like gaps of adjacent cuboidal mesothelial cells were almost completely occluded by a dense microvillous coat. As the submesothelial connective tissue was not identifiable with certainty, the mesothelial openings were regarded as corresponding to stoma-like structures. These findings yield further evidence that peritoneal stomata are obviously not confined to the diaphragmatic area but extend to other peritoneal regions. It is therefore suggested that these extra-diaphragmatic parietal and visceral peritoneal surfaces contribute to the absorption capacity of the entire peritoneum and are subsequently involved in either therapeutic procedures or pathological processes affecting the peritoneal cavity.

The experiment on mice was carried out by injecting intraperitoneally Chinese materia medica for treating hepatocirrhosis with ascites. Observations and a quantitative analysis were carried out on the pharmacological regulation of the peritoneal stomata by using a scanning electron microscope (SEM) and a computer image processing system attached to the SEM. There was a significant increase in both the diameter (P0.05) and distribution density (P0.01) of the peritoneal stomata in the red sage root and alismatis rhizome groups, whereas the effect of poria and poria peel was not significant compared with the control group (P0.05). Our findings confirm the effect of red sage root and alismatis rhizome on the regulation of the peritoneal stomata, which can enhance the absorption of ascitic fluid, taking into consideration the absorbent function of these stomata. They indicate that the patency of peritoneal stomata can vary in response to the effect of some Chinese materia. They also suggest that the ascites is drained mainly by means of enhancing the patency of the stomata and lymphatic absorption of the stomata during the process of treatment by traditional Chinese medicine.