Organs located retroperitoneally. MRI of the abdominal cavity and retroperitoneum
Retroperitoneal space located in the depths of the abdominal cavity - between the parietal fascia of the abdomen (back and sides) and the parietal peritoneum of the posterior wall of the peritoneal cavity (front). It contains organs not covered by the peritoneum (kidneys with ureters, adrenal glands) and areas of organs only partially covered by the peritoneum (pancreas, duodenum), as well as main vessels (aorta, inferior vena cava), giving off branches for the blood supply to all organs, lying both retroperitoneally and intraperitoneally. Along with them come nerves and lymphatic vessels and chains of lymph nodes.
Retroperitoneal space extends beyond the boundaries of the lumbar region as a result of the transition of its fiber into the hypochondrium and iliac fossa.
Walls of the retroperitoneum
Upper wall of the retroperitoneum- lumbar and costal parts of the diaphragm, covered with the parietal fascia of the abdomen, up to lig. coronarium hepatis on the right and lig. phrenicosplenicum on the left.
Posterior and lateral walls of the retroperitoneum- spinal column and muscles of the lumbar region, covered with fascia abdominis parietalis (endoabdominalis).
Anterior wall of the retroperitoneum- parietal peritoneum of the posterior wall of the peritoneal cavity. The visceral fascia of the retroperitoneal organs also takes part in the formation of the anterior wall: the pancreas, the ascending and descending colon.
The lower wall of the retroperitoneum there is no such thing. The conditional lower border is considered to be the plane drawn through the linea terminalis, separating the retroperitoneal space from the pelvis.
The retroperitoneal space, located deep in the lumbar region, is part of the abdominal cavity. In length, it significantly exceeds the lumbar region, since it is lengthened due to the cellular spaces located in the hypochondrium and iliac fossa.
The retroperitoneal space is located between the parietal peritoneum of the posterior abdominal wall and the intra-abdominal fascia (fascia endoabdominalis), which, lining the muscles of the posterior wall of the abdomen, acquires their names. At the top it is limited by the diaphragm, at the bottom it reaches the terminal line.
Retroperitoneal fascia:
1. Intra-abdominal fascia ( f. endoabdominalis).
2. Retroperitoneal fascia ( f. retroperitonealis) starts from the place of transition of the peritoneum from the lateral to the posterior wall of the abdomen, goes laterally and is divided into the prerenal (f. prerenalis) and the renal ( f. retrorenalis) fascia.
3. F. Toldti- located only along the ascending and descending colons.
The layers of the retroperitoneal space begin from the intra-abdominal fascia.
1. Retroperitoneal cellular space in the form of a thick layer of fatty tissue stretches from the diaphragm to the border line. Dividing to the sides, the fiber passes into the preperitoneal fiber of the anterior non-lateral wall of the abdomen. Medially behind the aorta and inferior vena cava it communicates with the same space on the opposite side. From below it communicates with the retrorectal cellular space of the pelvis. At the top it passes into the tissue of the subphrenic space and through the sternocostal triangle (Bochdalek triangle) communicates with prepleural tissue in the chest cavity. In the retroperitoneal space there are the aorta with the abdominal aortic plexus, the inferior vena cava, lumbar lymph nodes, and the thoracic duct.
2. The renal fascia begins from the peritoneum at the place of its transition from the lateral to the posterior wall of the abdomen (from the retroperitoneal fascia), at the outer edge of the kidney it is divided into posterior and anterior layers, limiting perirenal fiber. Medially it is attached to the fascial sheath of the aorta and inferior vena cava.
3. Pericolic tissue located behind the ascending and descending colons. At the top it reaches the root of the mesentery of the transverse colon, at the bottom - the level of the cecum on the right and the root of the mesentery of the sigmoid colon on the left, outside it is limited by the attachment of the renal fascia to the peritoneum, medially it reaches the root of the mesentery of the small intestine, behind it is limited by the prerenal fascia, in front - by the peritoneum lateral canals and retrocolic fascia. The retrocolic fascia (Toldi) is formed as a result of fusion of the layer of the primary mesentery of the colon with the parietal layer of the primary peritoneum during rotation and fixation of the colon; in the form of a thin plate it lies between the paracolic tissue and the ascending and descending colons, separating these formations.
The retroperitoneal space contains the kidneys, ureters, adrenal glands, the aorta and the inferior vena cava with its branches, the pancreas and duodenum.
GENERAL PART
Retroperitoneal space (spatium retro-peritoneale) located between the parietal peritoneum of the posterior abdominal wall and the intraperitoneal fascia (fascia endoabdominalis), which, lining the muscles of the posterior wall of the abdomen, acquires their names: the transverse abdominal muscle - transverse fascia (fascia transversalis), at the quadratus lumborum muscle - quadratic fascia (fascia quadrata), at the psoas major muscle - the psoas fascia (fascia psoatis)(rice. 11-83).
Layers of the retroperitoneum start from the intra-abdominal fascia (fascia endoabdominalis).
Rice. 11-83. Retroperitoneal cellular space (horizontal section). 1 - renal fascia, 2 - fatty capsule of the kidney, 3 - kidney, 4 - retroperitoneal tissue space, 5 - paracolic tissue, 6 - retrocolic fascia, 7 - external oblique abdominal muscle, 8 - internal oblique abdominal muscle, 9 - transverse abdominal muscle , 10 - intra-abdominal fascia, 11 - descending colon, 12 - prerenal fascia, 13 - peritoneum, 14 - aorta, 15 - inferior vena cava, 16 - ascending colon, 17 - quadratus lumborum muscle, 18 - psoas major muscle. (From: Lubotsky D.N. Fundamentals of topographic anatomy. - M., 1953.)
1 Retroperitoneal cellular space (textus cellulosus retroperitonealis) in the form of a thick layer of fatty tissue stretches from the diaphragm to the iliac fascia (fascia ilias). Dividing to the sides, the fiber passes into the subserosal base (tela subserosa) anterolateral abdominal wall. Medially behind the aorta and inferior vena cava it communicates with the same space on the opposite side. From below it communicates with the retrorectal cellular space of the pelvis. At the top it passes into the tissue of the subdiaphragmatic space and through the sternocostal triangle communicates with the subserosal base of the parietal pleura in the thoracic cavity. In the retroperitoneal cellular space there are the aorta with the abdominal aortic plexus, the inferior vena cava, lumbar lymph nodes, and the thoracic duct (Fig. 11-84).
Rice, 11-84. Retroperitoneal cellular space vert icapital cut). 1 - retrocolic fascia, 2 - oko-
colon fiber, 3 - descending colon,
prerenal fascia, 5 - pancreas, 6 - adrenal gland, 7 - kidney, 8 - fatty capsule of the kidney, 9 -
renal fascia, 10 - retroperitoneal cellular space, 11 - intra-abdominal fascia. (From: Lubotsky D.N. Basics topographic anatomy. - M., 1953.)
2. Postrenal fascia (fascia retrorenalis) is the posterior layer of the renal fascia (fascia renalis), which starts from the peritoneum at the place of its transition from the lateral to the posterior wall of the abdomen, at the outer edge of the kidney it is divided into posterior and anterior layers. The renal fascia separates the retroperitoneal cellular space from the perirenal cellular tissue, descends downwards behind the ureter and turns into the uretereal fascia (fascia retroureterica), which thins downwards and is lost in the lateral cellular space of the pelvis. Medially it is attached to the fascial sheath of the aorta and inferior vena cava.
3. Kidney fat capsule covers the kidney on all sides with an even layer from below and continues into the periureteric tissue. Above the fatty capsule of the kidney, there is a fascial-cellular sheath of the adrenal gland, isolated from the fatty capsule of the kidney and formed by the splitting of the prerenal fascia.
4. Kidney (hep), covered with a dense fibrous capsule (capsula fibrosa renis).
5. Kidney fat capsule .
6. Prerenal fascia (fascia praerenalis) is the anterior layer of the renal fascia (fascia renalis), above and on the sides it merges with the renal fascia, below it passes into the preureteral fascia (fascia prae-ureterica), which becomes thinner downwards and is lost in the lateral cellular space of the pelvis. The prerenal and retrorenal fascia form the fascial bursa for the kidney and its fat capsule; at the lower end of the kidney, these fasciae are connected to each other by jumpers that prevent the kidney from descending. From above, the leaves of the renal fascia are lost in the tissue of the subdiaphragmatic space.
7. Pericolic tissue (paracolon) concentrated behind the ascending and descending colon, its severity depends on the degree of fatness and can reach a thickness of 1-2 cm. At the top, the pericolic tissue reaches the root of the mesentery of the transverse colon, at the bottom - the level of the cecum on the right and the root of the mesentery of the sigmoid colon on the left, externally limited by the attachment renal fas-
tion to the peritoneum, medially reaches the root of the mesentery of the small intestine, is limited behind by the prerenal and preureteral fascia, in front by the peritoneum of the lateral canals and the retrocolic fascia.
8. Retrocolic fascia (fascia retrocolica) is formed as a result of fusion of the layer of the primary mesentery of the colon with the parietal layer of the primary peritoneum during rotation and fixation of the colon (see Fig. 11-27), lies in the form of a thin plate between the pericolic tissue (paracolon) and the ascending or descending colon, separating these formations.
9. Colon (column): in the right lumbar region - ascending colon (column ascendens), in the left - descending (colon descendens).
10. Visceral peritoneum (peritoneum visce-
rale).
The retroperitoneal space contains the kidneys, ureters, adrenal glands, the aorta and the inferior vena cava with its branches, the pancreas and duodenum. With the exception of the last two, which are discussed in the section “Organs of the Abdominal Cavity,” the organs of the retroperitoneal space are surrounded on all sides by fatty tissue.
Bud - a paired organ measuring about 10x5x4 cm and weighing approximately 150 g, located in the lumbar region. The kidneys are projected onto the anterior wall of the abdomen within the actual epigastric and subcostal regions.
Kidney position
The kidneys are located on the sides of the spine at the level from the XII thoracic to the II (sometimes III) lumbar vertebra (Fig. 11-85).
The right kidney lies lower than the left: if the XII rib divides the left kidney in half, then it cuts off the upper third from the right kidney. However, the height of the kidneys may vary. With a high position, the kidneys can be completely hidden behind the ribs; with a low position, they can be below the 12th rib. The different heights of the kidney position have significant surgical significance: with a high version of the position, to ensure adequate access it is necessary to resect the XII rib, and sometimes the two lower ribs.
The angle between the longitudinal axes of the kidneys is
lies above the level of the kidneys and ranges from 15 to 30°, since the distance between the upper poles of the kidneys (about 7 cm) is less than between the lower ones (about 10 cm).
Kidney syntopy
♦
The membranes of the kidneys are adjacent to the back
(rice. 11-86):
To the lumbar part of the diaphragm;
To the quadratus lumborum muscle;
To the transverse abdominal muscle;
To the psoas major muscle.
♦ The adrenal glands are adjacent to the upper pole of the kidneys.
♦ Adjacent to the membranes of the right kidney in front:
Right lobe of the liver;
Descending part of the duodenum;
Ascending colon and right flexure of the colon.
♦ Anteriorly to the membranes of the left kidney with
lies:
Posterior wall of the stomach;
Tail of the pancreas;
Spleen;
Left flexure of the colon;
Parietal peritoneum of the left mesenteric sinus.
Peritoneum at the transition from the kidney to neighboring ones
organs form ligaments: at the right kidney -
hepatorenal (lig. hepatorenal) and do-
odenorenal (lig. duodenorenale,
BNA) ligaments, in the left - splenorenal
new bunch (lig. lienorenale).
Kidney structure
In the kidney there are:
Front and back surfaces (facies anterior et posterior);
Top and bottom ends (extremitas superior
et inferior);
Medial and lateral edges (margo
medialis et lateralis).
♦ The lateral edge of the kidney has a convex surface throughout.
♦ The medial edge in the upper and lower third is also convex, and in the middle part it has a notch that contains the renal hilum (hilum renalis), passing into the renal sinus (sinus renalis), opening in the medial-inferior direction, since the distance between the upper ends of the kidneys is less than between the lower ones. The projection of the renal hilum onto the anterior abdominal wall is the intersection of the lateral edge of the rectus muscle
with a costal arch, which approximately corresponds to the anterior end of the XI rib. The projection of the renal hilum onto the posterior wall of the abdomen corresponds to the angle between the erector spinae muscle (i.e. erector spinae), and XII rib.
♦ Renal pedicle, suitable for kidney
gate, consists (listing in front
back) from the renal vein (v. renalis), by
renal artery (a. renalis) and renal
pelvis (pelvis renalis). Sometimes (in 30% of cases)
teas) renal arteries may not be
How many.
Kidney membranes (see. rice. 11-84) The kidney is covered with a fibrous capsule (capsula fibrosa), which after dissection can be easily separated from the parenchyma. Fatty capsule of the kidney (capsula adiposa renis) surrounds the fibrous capsule on all sides with an even layer. Transrenal and prerenal fascia (fasciae retrorenalis et praerenalis) separate the perinephric (perinephric) tissue from the retroperitoneal tissue at the back and the paracolic tissue at the front, joining together medially and attaching to the fascial sheath of the aorta and inferior vena cava, passing from below into the pre-ureteric (fascia praeureterica) and molar (fascia retroureterica) fascia. Kidney parenchyma(rice. 11-87) Behind the fibrous capsule covering the renal parenchyma is the renal parenchyma, which is divided into cortical (cortex renis) and brain (medulla renis) substance.
♦ The cortex is located inferiorly
from the base of the pyramids, comes between
Rice. 11-87. Bud. 1 - large renal calyces, 2 - renal pelvis, 3 - renal vein, 4 - renal artery, 5 - renal hilum, 6 - medial edge, 7 - upper end, 8 - renal cortex, 9 - small renal calyces, 10- lateral edge, 11 - renal medulla, 12 - renal column, 13 - lower end, 14 - ureter. (From: Sinelnikov R.D. Atlas of human anatomy. - M., 1972. - T. I.)
pyramids in the form of kidney columns (columnae renalis), contains renal corpuscles (corpusculi renales), proximal and distal convoluted tubules (tubuli renales contorti proximales et distales).♦ The medulla consists of 10-15 renal pyramids, the base of which is directed towards the outer surface of the kidney
ki, and the apex - towards the renal sinus. The renal pyramids contain straight tubules (tubuli renalis recti), nephron loops (ansa nephroni) and collecting ducts (ductus papillares), opening on the papillae (papillae renalis). Each renal papilla, formed by the connection of the apices of two or three pyramids, is surrounded by a funnel-shaped small renal calyx (calyx renalis minor). Several small calyces fuse to form a large renal calyx (calyx renalis major). Two or three large renal calyces unite to form the renal pelvis. Renal pelvis (pelvis renalis) has a funnel shape, the wide part of which is directed towards the hilum of the kidney, and the narrowed part passes into the ureter (ureter). The kidney parenchyma is divided into lobes and segments.
♦ Each renal pyramid with the surrounding cortex forms a renal lobe (lobus renalis). The renal lobes are clearly visible in early childhood, then the boundaries between them gradually smooth out.
♦ The kidney has five relatively independent segments in terms of blood supply: superior, anterior superior, anterior inferior, inferior, posterior. The thickness of the anterior segments corresponds to approximately 3/4 of the thickness of the kidney, the thickness of the posterior segment corresponds to 1/4 of the thickness of the kidney (Fig. 11-88). Therefore, when performing a nephrotomy, the kidney incision should be made by stepping back from the outer edge of the kidney by 1 cm in order to get into the border area between the blood supply zones.
Kidney fixation in the retroperitoneal space occurs due to:
Fatty capsule of the kidney (in case of severe
weight loss, drooping of the kidneys is often observed), the prerenal and retrorenal fascia, which give off jumpers to the fibrous capsule of the kidney;
The vascular pedicle on which the kidney hangs
like fruit on a branch;
Intra-abdominal pressure, which survives
moves the kidney with its membranes to the muscular renal bed formed posteriorly by the quadratus lumborum muscle, medially by the psoas major muscle, posteriorly and laterally by the aponeurosis of the transverse muscle, above the 12th rib by the diaphragm. Lumbar lordosis helps maintain the position of the kidney.
Blood supply, innervation, blood and lymph drainage
Blood supply the kidneys are carried out by the renal artery (a. renalis), approaching it as part of the renal pedicle between the renal vein and the renal pelvis. The renal arteries arise from the abdominal aorta (pars abdominalis aortae), Moreover, the right one is longer than the left one and passes behind the inferior vena cava (Fig. 11-89).
At the hilum of the kidney, the renal artery divides
on the posterior branch entering the posterior segment
ment of the kidney, and the anterior branch, from which
depart (Fig. 11-90):
♦
superior artery (a. segmenti
superioris);
Artery of the superior anterior segment (a. segmenti anterioris superioris);
♦ artery of the lower anterior segment (a. segmenti anterioris inferioris);
♦ artery of the lower segment (a. segmenti inferioris).
Accessory renal arteries entering
into the kidney outside the hilum, occurring in 30% of cases.
Bleeding occurs through the renal vein (v. renalis). The renal veins drain into the inferior vena cava (v. cava inferior), Moreover, the left one is longer than the right one and passes in front of the aorta. The left testicular (ovarian) vein drains into the left renal vein.Innervation of the kidney (Fig. 11-91)
Sympathetic prenodal nerve fibers
from the Th 12 -L 2 segments pass through the nodes
sympathetic trunk and are directed along
small splanchnic nerve (p. splan-
chnicus minor), to the lower visceral
nerve (n. splanchnicus imus) and lumbar
splanchnic nerves (pp. splanchnici
Rice. 11-90. Branching of the renal artery. 1 - ureteral branch, 2 - artery of the posterior segment, 3 - renal artery, 4 - adrenal artery, 5 - artery of the upper segment, 6 - artery of the upper anterior segment, 7 - artery of the lower anterior segment, 8 - artery of the lower segment.
lumbales) to the aortorenal nodes (ganglia aortorenalia). From these nodes post-nodal nerve fibers pass through the renal plexus (plexus renalis) are sent to the kidney, where they innervate mainly the vessels.
Sensory nerve fibers from the kidneys
along the lesser splanchnic nerve, inferior splanchnic nerve, lumbar splanchnic nerves and further along the white communicating branches (rami communicantes albi) reach the Th 12 -L 2 segments of the spinal cord. Pain from the kidney and upper ureter radiates to the lumbar and groin areas and along the medial inner thigh. Lymphatic drainage
The lymphatic vessels of the kidneys are divided into
divided into superficial and deep.
♦ Superficial lymphatic vessels are located in the thickness of the membranes of the kidney - in the renal fascia, perinephric tissue and fibrous capsule of the kidney.
♦ Deep lymphatic vessels provide lymph outflow from the renal parenchyma and follow the course of the intrarenal blood vessels to the hilum of the kidney.
Rice. 11-91. Innervation of the kidney. 1 - sacral plexus, 2 - inferior hypogastric plexus, 3 - ureter, 4 - renal artery and plexus, 5 - first lumbar splanchnic nerve, 6 - inferior splanchnic nerve, 7 - small splanchnic nerve, 8 - nodes of the sympathetic trunk, 9 - vagus nerve, 10 - spinal cord, 11 - celiac plexus, 12 - superior mesenteric plexus, 13 - aortorenal node, 14 - intermesenteric plexus, 15 - superior hypogastric plexus. (From: NetterF.H. Atlas of human anatomy. - Basle, 1989.)
Through the superficial and deep lymphatic vessels of the right kidney, lymph enters the lateral caval, precaval and postcaval lymph nodes (nodi lymphatici cavales laterales, praecavales, post-cavales), located to the right, in front and behind the inferior vena cava.
Through the superficial and deep lymphatic vessels of the left kidney, lymph enters the lateral aortic, preaortic and postaortic lymph nodes (nodi lymphatici aortici laterales, praeaortici, post-aortici), located to the left, in front and behind the aorta.
The inside of the human abdominal cavity is lined with a thin membrane called the peritoneum, which provides the secretion and absorption of a small amount of fluid for the better functioning of all organs. However, there are organs that this membrane does not affect: they are located behind the peritoneum. That is why the space limited in front by the peritoneum, and behind by the lumbar muscles and spine, is called retroperitoneal, or retroperitoneal. Its examination using ultrasound is often included in the standard protocol and is carried out together with ultrasound of the abdominal organs.
A little anatomy
To understand where retroperitoneum is localized, you just need to know where the lumbar region of the back is located. Now we can accurately name the organs located in the retroperitoneal space:
- kidneys with ureters;
- adrenal glands;
- the aorta and inferior vena cava, which run along the spine.
There are organs that are partially covered by the peritoneum and are located in the abdominal cavity, and the other part is located retroperitoneally. Such bodies include:
- pancreas;
- duodenum;
- part of the large intestine: ascending and descending colon.
In addition to the organs, the retroperitoneal space is filled with fatty tissue that performs a supporting function.
Ultrasound examination
Ultrasound of the retroperitoneum is today one of the most accessible methods for diagnosing pathology of the kidneys and adrenal glands. Examination of the vessels, pancreas and intestines is included in the examination of the abdominal organs, however, for emergency indications, sonography can be done of any structure whose pathology the doctor suspects, up to the soft tissue of the lumbar region if a hematoma is suspected. Retroperitoneum is examined for the following indications:
Preparing for an ultrasound
Depending on which organ or system needs to be emphasized, preparation for the procedure is somewhat different.
The common thing is that you need to take a diaper with you, on which you can lie during the procedure and wipe off any remaining gel after it. Some medical organizations provide disposable diapers, but you should take your own towel to dry yourself. It is necessary to take into account that wet wipes are not very good to use in this case, since they do not collect the gel that remains on the skin well.
Urinary system
No special preparations are required. However, you should pay attention to the drinking regime: you should not drink a lot before the ultrasound, as this will provoke active kidney function and may lead to incorrect interpretation of some indicators during the examination. For example, the renal pelvis, which collects urine from the kidney to the ureter and then to the bladder, may expand slightly.
An enlarged renal pelvis may indicate the presence of pathology or a normal physiological process.
Adrenal glands
They are a paired endocrine organ located at the upper poles of the kidneys. The tissue of the adrenal glands is practically invisible during ultrasound, so the doctor visually assesses the area of their location, in which any additional formations, if any, are clearly identified.
The area of the right adrenal gland is better visible, while the area of the left is more difficult to visualize. This is due to the peculiarity of the anatomical location of the adrenal glands themselves and neighboring organs. The stomach is adjacent to the left adrenal gland, so the study is carried out on an empty stomach.
On an empty stomach - this means that you cannot eat or drink 8 hours before the examination, because both solid and liquid food will interfere with the examination.
Aorta and inferior vena cava
To examine the vessels, you need a diet that excludes foods that promote fermentation and gas formation in the intestines, as well as taking medications such as:
- activated carbon or other enterosorbents;
- enzyme preparations, for example, Mezim, Festal, Pancreatin and others;
- Carminatives: Simethicone and its analogues.
Ultrasound examination of the retroperitoneal space
Before starting the examination, it is necessary to remove clothing from the area under examination, lie down on a couch previously covered with a diaper, and follow the instructions of a specialist who will apply the gel to the area under examination or directly to the sensor and begin the examination.
You need to be prepared for the fact that during the examination you will have to change your body position several times. If the aorta can be examined in the supine position, then the kidneys and adrenal glands must be examined from all sides, that is, in the supine position, on the side, on the stomach, sitting and standing.
Normal indicators and the most common pathology
A qualitative study of the retroperitoneal space using ultrasound is impossible without determining the norm.
Kidneys
The shape of a normal kidney is oval or bean-shaped, the contour is clear and even, sometimes wavy. The longitudinal size should not exceed 12 cm and be less than 10 cm. However, the size of the kidneys depends on the constitutional characteristics of a person and the type of his activity, for example, professional athletes may have larger kidneys.
The echostructure should be homogeneous, the echogenicity is average or normal, that is, the kidney parenchyma is slightly darker than the liver on ultrasound. The center of the bud, on the contrary, looks white.
Diffuse kidney changes
There is a change in the echostructure and echogenicity of the parenchyma of one or both kidneys.
Focal pathology
The most common formations detected by ultrasound of the kidneys are cysts. They can be single or multiple, small and giant, round and irregular in shape. Small cysts need to be monitored, that is, examined once a year. Very large sizes - removed.
Urolithiasis
Kidney pathology, characterized by the formation of stones of various compositions in the calyces or pelvis. When examined, the stones appear as a bright white structure that gives off a black shadow. They can be multiple or single, small or large, round, oval or irregular in shape.
Adrenal glands
Normally, this paired organ is not visualized.
Ultrasound of the retroperitoneal space most often reveals focal changes in the adrenal glands, the nature of which is quite difficult to judge, so the method of choice is computed tomography or magnetic resonance imaging.
Aorta
The normal diameter of the aorta is about 25 mm; if examination reveals an enlargement of a section of the vessel with a diameter of more than 30 mm, therefore, they speak of an aneurysm.
The doctor also pays attention to the walls of the aorta, since atherosclerotic plaques are often detected in older patients.
If there is a need to perform an ultrasound of the retroperitoneal organs, do not delay, since it is in the retroperitoneum that vital organs are located: the kidneys, adrenal glands and the two largest vessels of the body.
Table of contents of the topic "Abdominal part of the aorta. Lumbar plexus.":
There are three layers of fiber: actually retroperitoneal, perinephric and peri-intestinal.
The first layer of retroperitoneal tissue(otherwise - actual retroperitoneal tissue, textus cellulosus retroperitonealis), located after the parietal fascia (when accessed from behind, through all layers of the lumbar region). In front it is limited by the fascia extraperitonalis, in the back by the fascia abdominis parietalis, and above by the fusion of the lumbar part of the fascia abdominis parietalis with the diaphragmatic part at the level of the XII rib.
Inflammation of this area of retroperitoneal tissue called an extraperitoneal subphrenic abscess.
Below is the retroperitoneal tissue freely passes into the pelvic tissue. On the medial side, this layer is limited by the fusion of the fascia extraperitonealis with the fascial sheaths of the abdominal aorta, inferior vena cava and iliopsoas muscle. Laterally, the retroperitoneal tissue itself is limited by the fusion of the parietal peritoneum with the fascia abdominis parietalis and fascia extraperitonealis.
In the retroperitoneal tissue Hematomas of significant volume often accumulate when the vessels of the retroperitoneal space are damaged.
Second layer of retroperitoneal tissue, or the perirenal fat body, corpus adiposum pararenale, is located between the fascia retrorenalis and fascia prerenalis (split retroperitoneal fascia). This layer is divided into three sections: the upper one is the fascial-cellular sheath of the adrenal gland, the middle one is the fatty capsule of the kidney, capsula adiposa renis (paranephron), and the lower one is the fascial-cellular sheath of the ureter (paraureterium). The fascial-cellular sheath of the adrenal gland is isolated from the kidney tissue, and below the perinephric fiber is connected with the periureteric fiber.
Perirenal fat pad, corpus adiposum pararenale, is loose fatty tissue isolated from neighboring cellular spaces, covering the kidney on all sides and located between the fascial and fibrous capsules of the kidney. Its thickness varies individually, but it is greatest at the gate and lower end (pole) of the kidney. Below the kidney, fascial sheets are interconnected by connective tissue bridges and support the kidney in the form of a hammock.
Periureteric tissue, paraureterium, enclosed between the fascia preureterica and fascia retroureterica, is connected at the top with the paranephron, and at the bottom follows the course of the ureter along its entire length up to the small pelvis.
Third layer of retroperitoneal tissue located behind the ascending and descending parts of the colon and is called paracolic tissue, paracolon. At the back, this layer is bounded by the fascia extraperitonealis, and in the front by the fascia retrocolica, which covers the ascending (or descending) colon at the back, and the parietal peritoneum (bottom) of the lateral groove (canal) at the front. The thickness of the fiber in this space can reach 1-2 cm. At the top, the paracolon ends at the root of the mesocolon transversum, at the bottom in the iliac fossae on the right - at the cecum, on the left - at the root of the mesentery of the sigmoid colon. Laterally, the pericolic tissue reaches the junction of the parietal peritoneum with the retroperitoneal fascia, medially - to the root of the mesentery of the small intestine, slightly short of the midline.
In the pericolic tissue contains nerves, blood vessels, lymphatic vessels and nodes related to the large intestine.
