W. Lierse

The vascularization of liver metastases. Histological investigation of gelatine-injected liver specimens with special regard to the vascularization of micrometastases.

SummaryThe vascularization of 19 human livers with metastases was investigated using gelatine perfusion and resin corrosion techniques. (1) In 16 livers examined after injection via the hepatic artery hypervascular metastases were demonstrated in 12 cases, hypovascular in 4. (2) Injection via the portal vein showed that more than 50% of liver metastases had a distinct portal blood supply to the tumor periphery. In approximately one-third of cases the portal blood supply extended centrally. (3) Injection via the hepatic vein demonstrated venous drainage from peripheral areas of tumor in less than 30%, and from central areas in only 9%. Larger branches of the hepatic vein were not detected within metastases. (4) Tumor thrombi were seen within branches of the portal vein situated 1–1.5 cm from the tumor periphery in more than 50% of all liver metastases — suggesting the possibility of local hepatic retrograde tumor spread via the portal vein. (5) Central necroses were seen in hypervascular metastases only, mainly in tumors larger than 1–1.5 cm. (6) The incidence and vascularity of human hepatic micrometastases was investigated. Micrometastases were seen in close proximity to about 40% of the macrometastases. Metastases up to the size of 200 μm received their main blood supply via sinusoids. Neovascularization of tumors larger than 200 μm was demonstrated.

Sectorial Angioarchitecture of the Human Tibia

The blood supply of the periosteum of the human tibia was investigated by anatomical dissection of 12 lower extremities which were filled with injection mass. By division of the tibia into 4 segments (proximal and distal fifths; proximal and distal diaphysis) a general supplying system of the periosteum was found. The proximal fifth of the tibial periosteum is nourished by branches of the arteriae recurrentes tibiales anterior et posterior and the aa. inferiores medialis et lateralis genus. At the proximal diaphysis (next three tenths of the tibia) periosteal branches arise from the aa. tibialis anterior and posterior, whereas the distal diaphysis is nourished exclusively by semicircular vessels of the a. tibialis anterior which twine around the bone and merge with each other at the facies medialis. Concerning the periosteal blood supply of the distal fifth of the tibia, two different types were found. In two thirds of the cases the lateral side was nourished by branches of the a. tibialis anterior, which are supported by vessels from the a. fibularis. In one third the latter branch was absent so that the rami periostales arising from the a. tibialis anterior nourished the lateral aspect of the distal tibia alone. The dorsal region was supplied in all cases by rami of the a. fibularis and a. tibialis posterior. On the medial side the periosteal nourishment is ensured only by anastomosis. Branches of the a. tibialis anterior supply the facies lateralis and facies posterior where it is supported by vessels of the a. tibialis posterior and in a minor region of rami of the a. fibularis (distal) and a. poplitea (proximal).(ABSTRACT TRUNCATED AT 250 WORDS)

Microvascular architecture of the mucosa of the gastric corpus in man

Vascular casts of human gastric mucosa of the corpus area were studied by scanning electron microscopy and compared with vertical and horizontal series of semithin sections of perfusion-fixed corpus mucosa. The submucosal arteries give off short and long arterioles. The short arterioles branch into a basal capillary network reaching from the basis to the isthmus of the gastric glands. The long arterioles pass through the lamina propria without ramifications and supply a second, apical capillary layer reaching from the base to the top of the gastric pits. Anastomoses connect both capillary layers. Dense, convoluted capillaries at the mucosal surface encircle the gastric pits. Both capillary layers drain into venules at the level of the gastric pits. Below, on their way to the submucosal plexus, the venules do not receive any further capillary tributaries. In the examined tissue no arteriovenous anastomoses could be identified. A microvascular architecture with two capillary layers is presented, which guarantees a luxurious oxygenation throughout all layers of the gastric corpus mucosa in man. These findings are in contrast to previous descriptions of human corpus mucosa, where only one capillary layer, reaching from the base to the top of the corpus mucosa, has been identified.

Functional Construction of the Sacroiliac Ligamentous Apparatus

The sacroiliac ligamentous apparatus was examined as a part of a biomechanical pelvis-lower extremities system. The ligamentous apparatus of two pelves was freed, and the findings concerning the ligaments and their direction were drawn by a modular constructed, three-dimensional calculator model of the pelvic region. The ligamentous apparatus of the sacroiliac joint belongs to a functional system. Its task is to minimize every movement in this amphiarthrosis. The ligamentous apparatus shows an adaptation to strong or long-time-acting stresses. The junction between the os sacrum, pelvis and the ligamentous apparatus of the sacroiliac joint can be described as self-tightening. Local stresses are also reduced by the ligaments. A loosening in this system, which has to fix the os sacrum to the pelvic girdle, leads to a static insufficiency. The consequence is pain due to an irritation of the lumbosacral trunk. The exact description of the structure allows a representation according to the laws of similarity mechanics. With such a representation one can build up a computer-aided biomechanical model of the pelvis-lower extremities region. Examples for such a model are biomechanical finite-element models. By observing the laws of similarity mechanics (an exact description of geometric, physical and functional conditions) an efficient biomechanical model can be constructed that also takes into consideration the complex functional circumstances, in contrast to previous models. In order to construct such a model, one has to feed the findings of the examination into a data bank, which has to be demanded.

Thermische Nebeneffekte nach Anwendung gepulster IR-Laser am Meniskus- und Knochengewebe

Thermal effects on meniscus and bone tissue after application of 314 boreholes using five different infrared (IR) lasers: Nd:YAG, Tm:YAG, Ho:YAG, Er:YAG, Cr,Er:YSGG (application energy 200 mJ, 400 mJ, 600 mJ, 800 mJ, 1000 mJ; repetition rate 2 Hz, 5 Hz; medium air, water rinse) were analyzed. The experimental set-up comprised for the beam guiding a focussing lens (f = 100 mm) or a flexible fiber (Ho:YAG). Damaged tissue was investigated macroscopically, histologically, and by scanning electron microscopy. Application in air caused carbonisation in all cases. Application in water showed thermal brown discoloring using Tm:YAG, Ho:YAG laser on meniscus tissue. The Nd:YAG did not ablate. The Er:YAG laser showed macroscopically precise boreholes without any discoloring of the adjacent tissue as well in meniscus as in bone. Cr:ErYSGG laser results were comparable with the results using an Er:YAG laser although ablation on bone tissue created higher thermal effects. For the aim of developing minimal invasive operating techniques the Er:YAG laser showed best results.ZusammenfassungDie thermischen Nebenwirkungen fünf verschiedener Infrarot-(IR-)Laser (Nd:YAG, Tm:YAG, Ho:YAG, Er:YAG, Cr,Er:YSGG) wurden untersucht. In Meniskus- und Knochengewebe von Schlachttieren wurden insgesamt 314 Laserbohrungen gesetzt; Applikationsenergie 200 mJ, 400 mJ, 600 mJ, 800 mJ, 1000 mJ; Repetitionsrate 2 Hz, 5 Hz; Arbeitsmedium: Luft, Wasser. Der Laseraufbau erfolgte unter experimentellen Standardbedingungen. Für die Strahlführung wurde eine fokussierende Linse (f=100 mm) oder eine 600 μm Lichtleitfaser (Ho:YAG-Laser) eingesetzt. Die bohrlochnahen Gewebsschädigungen wurden makroskopisch, lichtmikroskopisch und rasterelektronenmikroskopisch untersucht. Applikationen an Luft verursachten bei allen fünf Lasern bereits makroskopisch deutlich sichtbare thermische Schädigungen. Unter Wasserspülung zeigten der Tm:YAG- und Ho:YAG Laser am Meniskus braune Gewebsverfärbungen; mit dem Nd:YAG-Laser war keine Abtragung an diesem Gewebe zu beobachten. Der Er:YAG Laser wies makroskopisch präzise Bohrlöcher auf und keine Gewebsverfärbungen. Bohrungen am Knochen mit Wasserspülung zeigten ebenfallst nur bei Anwendung des Er:YAG-Lasers saubere, thermisch nicht verfärbte Ränder. Die Ergebnisse des Cr:ErYSGG Lasers sind vergleichbar mit denen des Er:YAG-Lasers, jedoch stellte sich am Knochen eine höhere thermische Wirkung dar. Lichtmikroskopisch und rasterelektronenmikroskopisch bestätigte sich die oligothermische Wirkung des Er:YAG-Laser. Für die Zielstellung der Entwicklung minimal invasiver Operations-techniken am Hartgewebe mit IR-Lasern zeigte sich der Er:YAG-Laser daher als am besten geeignet.AbstractThermal effects on meniscus and bone tissue after application of 314 boreholes using five different infrared (IR) lasers: Nd:YAG, Tm:YAG, Ho:YAG, Er:YAG, Cr,Er:YSGG (application energy 200 mJ, 400 mJ, 600 mJ, 800 mJ, 100 mJ; repetition rate 2 Hz, 5 Hz; medium air, water rinse) were analyzed. The experimental set-up comprised for the beam guiding a focussing lens (f=100 mm) or a flexible fiber (Ho:YAG). Damaged tissue was investigated macroscopically, histologically, and by scanning electron microscopy. Application in air caused carbonisation in all cases. Application in water showed thermal brown discoloring using Tm:YAG, Ho:YAG laser on meniscus tissue. The Nd:YAG did not ablate. The Er:YAG laser showed macroscopically precise boreholes without any discoloring of the adjacent tissue as well in meniscus as in bone. Cr:ErYSGG laser results were comparable with the results using an Er:YAG laser although ablation on bone tissue created higher thermal effects. For the aim of developing minimal invasive operating techniques the Er:YAG laser showed best results.

Anastomosen zwischen Segmentarterien der Leber und phrenico-hepatische arterio-arterielle Anastomosen

SummaryA corrosion — cast anatomical study was performed on human livers. At first arterio-arterial anastomoses between the inferior phrenic arteries and branches of the main hepatic artery were investigated. Secondly, arterial communications between the right and left hepatic artery are described. 1. The anatomical-functional study of phrenico-hepatic anatomoses gives new detailed information on the arterial blood supply of the liver out of the phrenic arteries. These collaterals are a consistent finding. By far the largest part of the phrenicohepatic anastomoses is derived from the right inferior phrenic artery. The superior and posterior segments receive most of the anastomoses. In about 10 % of our cases we succeeded in filling almost the whole arterial system of the liver by injecting the inferior phrenic arteries. 2. There are three anastomotic pathways from the right hepatic artery to the left: the so-called portal anastomoses (hilar anstomoses), translobar vessels, and the capsular arteries.ZusammenfassungIn korrosionsanatomischen Untersuchungen an menschlichen Lebern wurde geprüft, welche arterio-arteriellen Anastomosen zwischen den Aa. phrenicae inferiores und ästen der A. hepatica propria bestehen. Ferner werden Anastomosen zwischen den Stromgebieten der Aa. hepaticae dextra et sinistra beschrieben. 1. Die anatomisch-funktionelle Untersuchung der phrenico-hepatischen Anastomosen bringt neue detaillierte Aufschlüsse über die arterielle Versorgung des Leberorgans aus den Schlagadern des Zwerchfells. Solche Collateralen existieren regelhaft. Den größten Teil der phrenico-hepatischen Anastomosen liefert die A. phrenica inferior dextra. Die superioren und posterioren Segmente nehmen die meisten Collateralgefäße auf. Bei nahezu 10 % der untersuchten Fälle war über die Collateralen eine Füllung fast des gesamten arteriellen Systems der Leber möglich. 2. Anastomosen zwischen beiden Leberarterien gibt es in Form der sogenannten portalen Anastomosen (Hilusanastomosen), der translobären Anastomosen und der Kapselarterien.

Vaskularisation von Lebermetastasen: eine korrosionsanatomische Studie

22 livers with multiple metastases from different primaries were injected with acrylate resin and examined stereoscopically. All metastases had •developed an individual pattern of vascularization. The

Das arterielle versorgungsprinzip der tibia und seine praktischen konsequenzen

SummaryIn the periosteum of the human tibia, the arterial blood supply shows a general sectorial angioarchitecture. There are 4 segments: proximal and distal 1/5, proximal and distal diaphysis. The proximal 1/5 of the tibial periosteum is supplied with blood by the aa. recurrentes tibiales anterior et posterior and the aa. inferiores medialis et lateralis genus. At the proximal diaphysis (next 3/10 of the tibia) periosteal branches arise from the a. tibialis anterior and the a. tibialis posterior. The distal diaphysis (following 3/10 below the middle of the tibia) is nourished exclusively by semicircular rami periostales of the a. tibialis anterior, which move around the bone from both sides and join with each other at the facies medialis. It is the only sector, which is supplied by a single main artery. Concerning the periosteal blood supply of the distal 1/5 of the tibia 2 different types are found. In 2/3 of the cases the lateral side is nourished by a great vessel of the a. fibularis, which is supported by branches arising from the a. tibialis anterior. In 1/3 of the cases this vessel of the a. fibularis is absent and rami periostales of the a. tibialis anterior nourish the lateral aspect of the distal tibia alone. The dorsal region is supplied in all cases by rami of the a. fibularis and a. tibialis posterior. On the medial side the periosteal nourishment is ensured only by anastomoses. Both the facies lateralis and the facies posterior are supplied by direct branches, which arise from the main arteries of the lower leg. The foramen nutricium is proximal on the dorsolateral side at an average of 33% of the tibial length. The a. nutricia has a caudal course up to 50% of the tibial length in the compacta. After passing the compacta the a. nutricia splits up in the medulla, its main vessel continues the caudal course at the edge of the dorsal compacta (endostal). The a. tibialis anterior is of great importance concerning the arterial supply of the periosteum and the outer aspect of the cortex of the tibia. The periosteum of the distal diaphysis is solely supplied by this blood vessel. There is a conspicuous correlation between this region and the location of pseudarthrosis. This area has the highest incidence for congenital and acquired pseudarthrosis. Therefore an osteo- or corticotomy should be avoided in the distal diaphysis. Neither should they be performed in the upper part of the proximal diaphysis, because one has to protect the a. nutricia. We recommend for those procedures the distal part of the proximal diaphysis just above the middle of the tibia and otherwise the frontier area of tibial head and proximal diaphysis. Furthermore, one has to take care of the a. tibialis anterior in revision of fractures and in plastic surgery. From the anatomical point of view the fixateur externe is to be preferred to plates and medullary nails, because the arteries are better protected. If a nail is necessary, a triangular one will save the endostal main artery.ZusammenfassungDie Arterien des Tibiaperiosts haben von proximal nach distal ein spezielles Versorgungs-system. Das proximale Funftel der Tibia wird von der A. recurrens tibialis anterior, der A. inferior lateralis genus, der A. inferior medialis genus and der A. recurrens tibialis posterior versorgt. In den folgenden 3/10 der Tibia wird das Periost durch ringförmige Anastomosen semizirkulärer Rr. periostales aus der A. tibialis anterior and der A. tibialis posterior ernährt. Die anschließenden 3/10 ab Tibiamitte werden ausschlieβlich durch Äste aus der A. tibialis anterior versorgt, die zirkulär and auch vertikal anastomosieren. Das kaudale Funftel der Tibia wird lateral meist aus der A. fibularis and aus der A. tibialis anterior oder auch nur durch die A. tibialis anterior versorgt, dorsal aus der A. fibularis mit Unterstützung durch die A. tibialis posterior, medial nur durch Anastomosen. Die Facies lateralis wird hauptsächlich von Ästen der A. tibialis anterior versorgt, die Facies posterior von Ästen aus der A. tibialis anterior, der A. tibialis posterior und zum geringen Teil aus der A. fibularis and der A. Diese Arbeit ist durch das Zentrum für Biomechanik der Universitat Hamburg geffirdert. poplitea. Sowohl die Facies lateralis als auch die Facies posterior erhalten eine direkte Versorgung durch Rami aus den Hauptgefäßen, im Gegensatz zur Facies medialis, die nur durch Anastomosen mitversorgt wird. Das Foramen nutricium liegt dorsolateral in der durchschnittlichen Höhe von 33 % der Tibialdnge. Die A. nutricia zieht in der Kompakta nach kaudal, liegt aber 50% der Tibialänge frei im Markraum and spaltet sich dort knäuelför-mig auf. Ihr Hauptgefäß setzt ihren Verlauf nach kaudal am Rand der Kompakta fort, also endostal. Die A. tibialis anterior ist das Hauptgefäß für die arterielle Versorgung des Tibiaperiosts. Ihr autonomes Versorgungsgebiet, die distale Diaphyse, stimmt mit der Lokalisation der erworbenen und angeborenen Pseudarthrosen über-ein. Eine Kortikotomie ist daher in diesem Bereich zu vermeiden; ebenso sollte der obere Teil der proximalen Diaphyse wegen der Gefdhrdung der A. nutricia vermieden werden. Daher sind die Tibiamitte and die Grenzzone zwischen dem Tibiakopf and der proximalen Diaphyse günstige Stellen. Bei Muskeltransplantationen ist die A. tibialis anterior als Hauptgefäβ für das Tibiaperiost zu schonen. Unter den Osteosyntheseverfahren ist aus anatomischer Sicht der Fixateur externe gegenüber Platten und Markndgeln vorzuziehen, da die arterielle Versorgung besser erhalten bleibt. Ist eine Marknagelung indiziert, so bieten dreieckige Markndgel die Möglichkeit, endostale Hauptgefäße zu schonen, zum einen durch den Verzicht auf die Aufbohrung, zum anderen durch die Ausrichtung der Spitze des Dreiecks nach ventral. So bleibt im dorsalen Bereich der Tibia ein Kanal für das endostale Hauptgefäβ erhalten.

The hypoganglionic and aganglionic high pressure zone of the anterior esophagus (the esophageal opening) and its special blood supply (angiomuscular sphincter closure

At the mouth of the oesophagus there is an aganglionic zone similar to that in the anorectal organ of continence. This is part of the system of permanent closure. Since the musculature at the oesophageal entrance is arranged in a screw-like fashion the aganglionic zone lies obliquely to the longitudinal axis of the oesophagus. Closure at the oesophageal entrance is further supported by a kind of corpus cavernosum similar to that in the rectum. In this pharyngeal corpus cavernosum blood is drained between the muscular fibres and their contraction prevents its drainage, thus facilitating the closure of the musculature. The constrictor pharyngeus muscle takes a similar course as does the puborectalis which leads to a bend in the anal canal. Thus also at the entrance to the gastrointestinal tract an arterial angiomuscular system of closure exists in the center of which an aganglionic segment is conspicuous.SummaryAt the mouth of the oesophagus there is an aganglionic zone similar to that in the anorectal organ of continence. This is part of the system of permanent closure. Since the musculature at the oesophageal entrance is arranged in a screw-like fashion the aganglionic zone lies obliquely to the longitudinal axis of the oesophagus. Closure at the oesophageal entrance is further supported by a kind of corpus cavernosum similar to that in the rectum. In this pharyngeal corpus cavernosum blood is drained between the muscular fibres and their contraction prevents its drainage, thus facilitating the closure of the musculature. The constrictor pharyngeus muscle takes a similar course as does the puborectalis which leads to a bend in the anal canal. Thus also at the entrance to the gastrointestinal tract an arterial angiomuscular system of closure exists in the center of which an aganglionic segment is conspicuous.ZusammenfassungAm Oesophagusmund ist, wie beim anorectalen Kontinenzorgan, eine hypo- bzw. aganglionäre Zone entwickelt. Sie bewirkt den dauernden Abschluß. Da die Oesophagusmundmuskulatur aus schraubig angelegten Fasern entwickelt ist, liegt die ganglienzellose Zone schräg zur Längsachse der Speiseröhre. Der Abschluß wird durch eine Art Schwellkörper unterstützt, der dem Corpus cavernosum recti ähnlich ist. Auch bei diesem Schwellkörper im Pharynx läuft das Blut zwischen den Muskelfasern ab und wird bei deren Kontraktion angestaut zurückgehalten. Dies vollendet auch hier den Abschluß. Der M. constrictor pharyngeus hat einen ähnlichen Verlauf wie der M. puborectalis, der am Analkanal eine Abknickung neben seinem Dauertonus bewirkt. Somit liegt auch am Beginn des Gastrointestinaltraktes ein arterielles angiomusculäres Verschlußsystem vor, in dessen Mittelpunkt ein aganglionärer Abschnitt auffällt.

Bioconstruction of the extrahepatic biliary duct system in minipigs: comparing normal condition with experimental obstruction

The extrahepatic biliary duct system is subject to a particular bioconstruction to secure its bile transport function. The dominant structure of the bile duct wall is a network of collagen fibres harboring muscle-fibre bundles. The collagen fibres are virtually inelastic, volumes can be changed only by rearranging the network. The ducts show different spatial arrangements of the fibres causing different extents of dilatation during obstruction. Extreme dilatation might cause a rupture of the network, and deficient postoperative retonisation could be the result.