Splenic Rhythms and Postprandial Dynamics in Physiology, Portal Hypertension, and Functional Hyposplenism: A Review.

BACKGROUND: Before the discovery of immunological and haematological functions of the spleen, it had for centuries been considered to be a digestive organ of variable size with a role in the portal vein system and nutritional metabolism. In the 19th and 20th centuries, volume changes in the spleen related to nutrition were studied using plethysmographic measurements. Rhythmical and regulatory functions of the spleen were demonstrated in the haemodynamics of the splanchnic region and were described as a "hepatolienal pendulum," a "Windkessel function," or a "pressure compensation." These studies were mainly published in German-speaking countries and have not, as far as is known, been discussed in the English-speaking world so far. SUMMARY: This review explores the historical development of the rhythmical regulatory function of the spleen in the splanchnic region. Older studies and results are followed up in the modern literature, wherever possible, up to the present. The clinical relevance is illustrated with portal hypertension (with congestive or hyperdynamic splenomegaly), coeliac disease, and chronic inflammatory bowel diseases (with functional hyposplenism). Key Message: The spleen's rhythmical regulatory function in nutrition is based on an autonomous rhythm comprising cycles of contractions and dilations of the spleen of around 1 min. These cycles can be influenced by sympathetically mediated single contractions with a release of pooled blood or by portal vein congestion. After food ingestion, the spleen responds either with contraction according to a vasomotor reaction or postprandial congestion with significant increases in volume. The spleen's rhythmical function is lost in the clinical picture of portal hypertension or in coeliac disease and chronic inflammatory bowel diseases. In the aforementioned gastrointestinal diseases, we recommend taking more account of the haemodynamics between the spleen, liver, and intestine. New innovative techniques for recording splenograms are required which, besides elastographic measurements of spleen stiffness, could offer an important tool for early detection, diagnosis, and therapeutic evaluation.

Does the Spleen Have a Function in Digestion? Medical History, Phylogenetic and Embryological Development of the Splenogastric System.

BACKGROUND: Before the spleen was discovered to be a lymphatic blood organ, it had for centuries been considered to be a digestive organ. Concepts of a regulative, secretory and resorptive function in the digestive system were based mainly on a postulated connection between the stomach and the spleen. Splenogastric vascular connections have recently been rediscovered by modern surgery. SUMMARY: To test the hypothesis that the spleen has a digestive function, this article reviews the literature focusing on the interaction between the spleen and the stomach. We examine the historical medical view of the spleen and stomach system and the reasons why a digestive function was abandoned in the 17th and 18th centuries. We then review the rediscovery of the splenogastric system and the present-day state of knowledge (anatomical origin, variability, haemodynamics) and present it in terms of the phylogenetic and embryological development of the spleen and stomach system. Key Message: Splenogastric arteries and gastrosplenic veins form a portal system which directly connects the spleen and stomach parenchyma. Despite its mesodermal anlage, phylogenetically and embryologically the spleen is intimately interconnected with the entodermal stomach parenchyma but detaches from this in the course of development. Further study is required to establish whether the splenogastric system is merely an evolutive remnant or actually a part of a functioning spleen-stomach system as postulated in complementary and integrative medicine.

Postprandial dynamics of splenic volume in healthy volunteers.

Throughout the history of medicine, many functions have been attributed to the spleen and numerous researchers have focused on a postulated digestive function. Beginning in 1825, systematic animal studies showed evidence for a postprandial increase in splenic volume (SV) with a peak 30 min to five hours after food intake. Since the introduction of imaging techniques, two studies have been conducted on humans, revealing a decrease in SV 30 to 45 min postprandially. The aim of this study was to examine possible postprandial changes in SV over a period of seven hours. The ethics-approved, randomized crossover study included 10 healthy volunteers, who received a standardized meal (3,600 kJ) on one study day and fasted on the other. Sonographic measurements were obtained at six measurement points on each day. Thirty minutes after the meal, SV increased significantly by 38.2 ± 51.2 cm3 (17.3%; p = .04) compared to the baseline measurement and decreased gradually afterward. In males, SV 30 min after the meal was 70.2 ± 21.6 cm3 higher (p = .002) compared to the fasting condition and 60 min later it was still significantly increased. The apparent SV increase after food intake is discussed in relation to hemodynamic changes in the splanchnic region. It seems plausible that the spleen has a rhythmic and regulative function within the portal system, something which warrants further research and should be taken more into account in nutritional physiology.

[Recommendations for problem solving in integrative postgraduate medical training of physicians at anthroposophic hospitals in Germany and Switzerland]. / Lösungsvorschläge für Probleme in der integrativmedizinischen Weiterbildung von Ärzten an anthroposophischen Kliniken Deutschlands und der Schweiz.

BACKGROUND: In the context of the first-time evaluation of the quality and problems of integrative postgraduate medical training (PGMT) at German and Swiss anthroposophic hospitals, all 240 trainees and all 214 trainers were asked to propose options for problem solutions. METHOD: The study included a cross-sectional questionnaire survey with sections for further comments. The data were evaluated with qualitative content analysis (Mayring). 56 (51.8%) out of 108 responding trainees and 54 (54%) out of 100 responding trainers had given potential solutions. Both groups were analyzed together. RESULTS: On internal level, recommendations comprised re-orientation on a leadership basis, i.e. elevation of PGMT to a core element of hospital policy in anthroposophic medicine (AM), as well as better personnel policy; trainers with more professional and teaching competency in AM; structured and extended continual education program; coordination of PGMT with ward and hospital organization; and work load reduction for physicians through process optimization and resource planning. Externally, the recommendations embraced financial support; external training programs; networking of anthroposophic hospitals in PGMT; implementation of a common competence center for anthroposophic PGMT; conventional and anthroposophic PGMT curriculums; and improvement of science base and public discourse of AM. CONCLUSION: The proposed options for problem solving in PGMT at anthroposophic hospitals emerge from concrete problem perceptions of the trainers and trainees. They can serve as a basis for concrete improvements of PGMT in AM that could be implemented professionally and in an international context. The preconditions for this are given through the already existing establishment of AM at universities and through the good international connections of anthroposophic hospitals and anthroposophic physicians' associations.

[Problems in integrative postgraduate medical training of physicians at anthroposophic hospitals in Germany and Switzerland]. / Probleme in der integrativmedizinischen Weiterbildung von Ärzten an anthroposophischen Kliniken Deutschlands und der Schweiz.

BACKGROUND: Anthroposophic hospitals provide integrative medical care by complementing conventional (CON) with anthroposophic medicine (AM). They teach integrative medicine in postgraduate medical training (PGMT). In a first evaluation of PGMT quality in AM, we analyzed the problems of this training from the perspectives of trainers and trainees. METHOD: We conducted an anonymous cross-sectional full survey of all trainee and trainer physicians at the 15 AM hospitals in Germany (DE) and Switzerland (CH) with questionnaires of the Swiss Institute of Technology (ETH) Zürich, complemented by a module for AM. We also conducted descriptive statistics for questions with answering scales as well as calculations of group differences (two-tailed Mann-Whitney U test) and a qualitative content analysis (Mayring) of free text answers related to the problem analysis. RESULTS: The response rate in DE embraced 89 out of 215 (41.39%) surveyed trainees and 78 out of 184 (42.39%) trainers; in CH, the response rate comprised 19 out of 25 (76%) trainees and 22 out of 30 (73.33%) trainers. Free text answers related to problem analysis in DE and CH were given by 16 out of 108 (14.8%) trainees and by 20 out of 100 (20%) trainers, overall. Perceived main problems include work overload; shortcomings in work organization; delimitation of competences; interprofessional cooperation; financial resources (trainers); wages (trainees DE); practical relevance of AM (trainees and trainers in DE); professional or didactic competence of trainers; lack of interest in AM (trainees); problems with learning and practicing AM; no curriculum for postgraduate medical training in AM; tensions between AM and CON. Explanations for the differences between DE and CH include larger departments and the DRG system in DE, but also better structural conditions for AM PGMT in CH. CONCLUSION: Main problems of PGMT in AM include not only non-specific and systemic aspects, but also AM-specific issues. In order to develop a basis for concrete problem solving options, this study will be complemented by an analysis of solution ideas from the perspective of the involved trainers and trainees.

The subjectively perceived quality of postgraduate medical training in integrative medicine within the public healthcare systems of Germany and Switzerland: the example of anthroposophic hospitals.

BACKGROUND: Integrative medicine (IM) integrates evidence-based Complementary and Alternative Medicine (CAM) with conventional medicine (CON). Medical schools offer basic CAM electives but in postgraduate medical training (PGMT) little has been done for the integration of CAM. An exception to this is anthroposophic medicine (AM), a western form of CAM based on CON, offering an individualized holistic IM approach. AM hospitals are part of the public healthcare systems in Germany and Switzerland and train AM in PGMT. We performed the first quality evaluation of the subjectively perceived quality of this PGMT. METHODS: An anonymous full survey of all 214 trainers (TR) and 240 trainees (TE) in all 15 AM hospitals in Germany and Switzerland, using the ETHZ questionnaire for annual national PGMT assessments in Switzerland (CH) and Germany (D), complemented by a module for AM. Data analysis included Cronbach's alpha to assess internal consistency questionnaire scales, 2-tailed Pearson correlation of specific quality dimensions of PGMT and department size, 2-tailed Wilcoxon Matched-Pair test for dependent variables and 2-tailed Mann-Whitney U-test for independent variables to calculate group differences. The level of significance was set at p < 0.05. RESULTS: Return rates were: D: TE 89/215 (41.39%), TR 78/184 (42.39%); CH: TE 19/25 (76%), TR 22/30 (73.33%). Cronbach's alpha values for TE scales were >0.8 or >0.9, and >0.7 to >0.5 for TR scales. Swiss hospitals surpassed German ones significantly in Global Satisfaction with AM (TR and TE); Clinical Competency training in CON (TE) and AM (TE, TR), Error Management, Culture of Decision Making, Evidence-based Medicine, and Clinical Competency in internal medicine CON and AM (TE). When the comparison was restricted to departments of comparable size, differences remained significant for Clinical Competencies in AM (TE, TR), and Culture of Decision Making (TE). CON received better grades than AM in Global Satisfaction and Clinical Competency. Quality of PGMT depended on department size, working conditions and structural training features. CONCLUSION: The lower quality of PGMT in German hospitals can be attributed to larger departments, more difficult working conditions, and less favorable structural features for PGMT in AM, possibly also in relation to increased financial pressure.

Impact of colored light on cardiorespiratory coordination.

Background. Light exposure to the eye can influence different physiological functions, for example, the suprachiasmatic nucleus (SCN). By affecting the autonomic nervous system, the SCN may influence the heart rate variability (HRV). Standardized colored light exposure alters HRV but the results are inconsistent. In this study we investigated the effects of nonstandardized red light (approx. 640 nm) and blue (approx. 480 nm) light (approx. 50 lx) on cardiorespiratory coordination and HRV. Methods. 17 healthy subjects (7 males, age: 26.5 ± 6.2 years) were exposed to the following sequence (10 minutes each): daylight-red light-daylight-blue light-daylight. Red and blue lights were created by daylight passing through colored glass panes. Spectral measures of HRV (LF: low frequency, HF: high frequency oscillations, and sympathovagal balance LF/HF) and measures of cardiorespiratory coordination (HRR: heart respiration ratio, PCR: phase coordination ratio) were analyzed. Results. The LF component increased and the HF component decreased after red light. Consequently, LF/HF increased after red light. Furthermore, during red light HRR and PCR confined to 4 : 1, that is, 4 heartbeats during one respiratory cycle. Conclusion. Nonstandardized red and blue lights are able to alter the autonomic control reflected by HRV as well as cardiorespiratory coordination.