Retropertoneal Organs PDF

RETROPERTONEUM & PRIMARY RETROPERITONEAL ORGANS August 2023 1. 2.Primary retroperitoneal Retropertoneu m,organs 1. The suprarenal gland 2. The kidneys 3. The ureters 2 1. Retroperitoneum the region behind peritoneum : anterior...

RETROPERTONEUM & PRIMARY RETROPERITONEAL ORGANS August 2023 1. 2.Primary retroperitoneal Retropertoneu m,organs 1. The suprarenal gland 2. The kidneys 3. The ureters 2 1. Retroperitoneum the region behind peritoneum : anterior to posterior abdominal wall can be further subdivided into three 1.Perirenal (or perinephric) space 2.Anterior pararenal (or paranephric) space 3.Posterior pararenal (or paranephric) space 1. Perirenal space Bounded by the anterior and posterior leaves of the renal fascia The renal fascia is a layer of CT encapsulating the kidney and suprarenal gland It can be divided into: 1. the anterior renal fascia 2. the posterior renal fascia, or fascia retrorenalis 4 Anterior renal fascia Anterior attachment:  passes anterior to the kidney, renal vessels, abdominal aorta and inferior vena cava  fuses with the anterior layer of the renal fascia of the controlateral part Posterior attachment:  fuses with the psoas fascia and side of the body of the vertebrae Superior attachment:  the anterior and posterior layers fuse at the upper pole of the kidney and then split to enclose the adrenal gland.  at the upper part of the adrenal gland, they again fuse to form the suspensory ligament of the gland and fuse with the diaphragmatic fascia. Inferior attachment: 5  The layers do not fuse.  the posterior layer descends downwards and fuses with  1.Perirenal (or perinephric) space contains the following structures: Kidneys Adrenal gland Renal vessels Suprarenal vessels Ureters 2. Anterior pararenal space Bounded by: the posterior layer of peritoneum the anterior leaf of the renal fascia. 6 contains the following structures: 3. Posterior pararenal space Bounded by : the posterior leaf of the renal fascia and the muscles of the posterior abdominal wall. It contains only fat. 1. Suprarenal glands Are yellowish in color in living persons Lies on each side of the vertebral column Located between the superomedial aspects of the kidneys and the diaphragm surrounded by connective tissue containing considerable perinephric fat. enclosed by renal fascia - attached the gland to the crura of the 1 diaphragm 0 Suprarenal gland  is about 4–6 cm long,  1–2 cm wide, and 4–6 mm thick in adults  together they weigh about 8 g primary relationship → the kidney major attachment of the glands →the diaphragmatic crura. They are separated from the kidneys by a thin septum, part of the renal fascia 1 1 1 2  The shape and relations of the suprarenal glands differ on the two sides 1.The right suprarenal gland: pyramidal in shape with its apex superiorly and its base embracing the kidney lies at the level of T12 is rested on the superior pole of the right kidney lies between the diaphragm posteriorly and the IVC anteromedially the right lobe of the 1 liver anteriorly 3 superior to this gland lies  The right suprarenal gland: is at the level of the omental foramen, indicated by the black arrow 1 2 2. The Left suprarenal is semilunar or crescent gland in shape larger than the right extends further inferiorly on the medial margin of the kidney than does the right extends medial to the superior half of the left kidney Lies at the level of T12 – L2 lies in the stomach bed Adrenal gland is related anterior to the stomach, the spleen and pancreas 1 3 1 4  Each suprarenal gland has two parts: 1. the suprarenal cortex 2. suprarenal medulla the two parts have different embryological origins and different functions. 1 5 1. Suprarenal cortex: derives from mesoderm vital for life constitute the major part of the gland secretes corticosteroids and androgens Mineralocorticoid Glucocorticoid Sex corticoid (Androgen) 1 6 2. Suprarenal medulla derived from neural crest cells associated with the sympathetic nervous system has cell populations known as chromaffin cells – related sympathetic ganglion (postsynaptic) both in derivative and function cells secrete catecholamine hormones, mainly epinephrine (80%) & norepinephrine (20%) 1 7 Blood supply of suprarenal 1. Suprarenalgland arteries and veins The suprarenal arteries: branch freely before entering each gland so that 50-60 branches penetrate the capsule covering the entire surface of the glands. Suprarenal arteries arise from three sources: 1. Superior suprarenal arteries 2. (6-8) Middle suprarenal from arteries the inferior - from the abdominal phrenic aorta neararteries the level of origin of the SMA 3. Inferior suprarenal 2 0 arteries Note: - from The number the and renal of patterns arteries. of the suprarenal arteries are arrangement The venous drainage: via large suprarenal veins The short right suprarenal vein drains into the IVC the longer left suprarenal vein, often joined by the inferior phrenic vein, empties into the N.B: leftThe endocrine renal vein function of the suprarenal glands make their abundant blood supply necessary 2 1 2 0 Lymphatic lymphatic vessels drainage: arise from a plexus deep to the capsule of the gland and from one in its medulla. the lymph passes to the lumbar lymph nodes. many lymphatic vessels leave the suprarenal glands 2 1 Nerve supply suprarenal gland The rich nerve supply of the suprarenal glands: is from the celiac plexus abdominopelvic (greater, lesser, and least) splanchnic nerves. Myelinated presynaptic sympathetic fibers:  mainly derived from the intermediolateral cell column (IML), or lateral horn, of gray 2 4 2. The kidneys Vital organ of the urinary system Perform three main functions: 1. Filtration 2. Secretion 3. Excretion 2 3 Surface anatomy of the kidneys Hilum of the left kidney lies near the transpyloric plane, ≈ 5 cm from the median plane The transpyloric plane passes through the superior pole of the right kidney, Posteriorly, the superior parts of the kidneys lie deep to the 11th and 12th ribs inferior pole of the right kidney is ≈ a finger's breadth superior to the iliac crest. Palpation of the right kidney is 2 4 Palpation of the kidney To palpate the kidneys, press the flank, (the side of the trunk between the 11th and 12th ribs and the iliac crest), anteriorly with one hand while palpating deeply at the costal margin with the other The left kidney is usually not palpable unless it is enlarged or a retroperitoneal mass has displaced 2 5 Renal angle: is the angle between the lower border of 12th rib and the lateral border of erector spinae miscle It is so called because the kidney can easly be felt at this location. 2 6 Coverin 1.Fibrous gs capsule: surrounds the kidney and is closely applied to its outer surface. 2.Perirenal fat: surrounds the kidneys and their vessels extends into their hollow centers, the renal sinuses the covers the fibrous capsule 3.Renal fascia: is a condensation of CT outside the perirenal fat encloses the kidneys and suprarenal glands continuous laterally 4 with the 2 fascia transversalis. continues medially to 4. Pararenal lies external to the fat renal fascia and is often in large quantity it forms part of the retroperitoneal fat The perirenal fat, renal fascia, and pararenal fat support the kidneys and hold (fix) them in position on the posterior abdominal wall 4 3 KIDNEY S Lie retroperitoneally the on posterior wall, one on each abdominal the side vertebral of of the T12 - the level column at vertebr L3 ae The right kidney lies slightly inferior to usually left the kidney, owing probably to its to the relationship liver are reddish brown life during Shape: Bean shaped H as 10 cm in length, in 5 width, and 2.5 cm thicknes cm in 4 s. weight is about 130 – 4 150 gm External anatomy of kidney Each kidney has: Two surfaces : anterior surface posterior surface Two poles: superior pole Inferior inferior pole pole Two borders: medial border lateral border 4 5  At the concave medial margin of each kidney is a vertical cleft, the renal hilum the renal the hilum renal arteryis enters the siteand where: the renal vein and renal pelvis leave the renal sinus at the hilum, the renal vein is anterior to the renal artery, which is anterior to the renal pelvis (vein- artery-pelvis). The renal hilum is the entrance to a space within the 4 6 kidney, the renal sinus  The renal pelvis: is the flattened, funnel- shaped expansion of the superior end of the ureter The apex of the renal pelvis is continuous with the ureter. receives two or three major calices (calyces), each of which divides into two or three minor calices. Each minor calyx is indented by the renal papilla, the apex of the renal pyramid 3 2 In living persons, the renal pelvis and its calices 3 3 Each pyramid has: a base towards the cortex an apex known as renal papillae. In human, 10 – 18 renal papillae are perforated by 10 – 25 orifices of collecting ducts Theand are termed cortical tissue in between the renal pyramids is lamina known as cribrosa the renal column of Bertini. The renal tissue characterized by the renal medullary rays each ray passes from the base of renal pyramid to nearly the renal capsule. The kidney can be divided to lobes and lobules:  The renal lobe: is one medullary pyramid and its corresponding area of cortical tissue – renal column  The renal lobule: is the mass of cortical tissue surrounding a medullary ray 3 5 3 6 Relations of the kidneys Right Anteriorly: Kidney The suprarenal gland the liver the second part of the duodenum the right colic flexure 3 7  Relation, right kidney Posteriorly: The diaphragm the costodiaphragmati c recess of the pleura the 12th rib the psoas quadratus lumborum, and transversus abdominis muscles. The subcostal (T12), iliohypogastric, and ilioinguinal nerves (L1) run downward and laterally 5 4 Left Kidney Anteriorly: the suprarenal gland the spleen the stomach the pancreas the left colic flexure coils of jejunum 5 5  Relation, left kidney Posteriorly: The diaphragm the costodiaphragmatic recess of the pleura the 11th (the left kidney is higher) and 12th ribs the psoas, quadratus lumborum, and transversus abdominis muscles. The subcostal (T12), iliohypogastric, and ilioinguinal nerves (L1) run downward and laterally 5 6  Blood Supply of the kidneys Arterial supply The renal arteries: arise from the aorta at the level of L2 Each usually divides into five segmental arteries that enter the hilum of the kidney are distributed to different segments or areas of the kidney Lobar arteries arise from each segmental artery, one for each renal pyramid Before entering the renal substance, each lobar artery gives off two or three inter- lobar arteries Blood Supply of the kidneys The interlobar arteries run toward the cortex on each side of the renal pyramid. At the junction of the cortex and the medulla, the interlobar arteries give off the arcuate arteries, which arch over the bases of the pyramids The arcuate arteries give off several interlobular arteries 5 that ascend in the 8 cortex. 6 0 Renal segments According to its arterial supply, the kidney has five segments: superior (apical) Anterosuperior Anteroinferior inferior, and posterior. Typically, the renal artery divides into five branches, each supplying a segment of the kidney 6 1  6 Although the veins of the kidney 2 anastomose freely, segmental Veins of the kidneys The renal vein emerges from the hilum in front of the renal artery drains into the inferior vena cava. Lymph drainage Lymph drains to the lateral aortic lymph nodes around the origin of the renal artery. 6 3 Nerve Supply The nerve supply is the renal sympathetic plexus. The afferent fibers that travel through the renal plexus enter the spinal cord in the 10th, 11th, and Most 12th of the fibers conveyed by thenerves. thoracic spinal abdominopelvic Figure: A. The nerves of the splanchnic nerves to kidneys and suprarenal glands the prevertebral are derived from the celiac ganglia are plexus, abdominopelvic (lesser presynaptic sympathetic fibers and least) splanchnic nerves, that passed through and the aorticorenal ganglion the paravertebral 4 8 ganglia without Clinical considerations Perinephric Abscess: The attachments of the renal fascia determine the path of extension of a perinephric abscess Nephroptosis (floating kidney) is increased or abnormal mobility of the kidneys downward displacement of the kidneys out of their normal position when they stand up may be caused in part by any event that weakens the ligaments that hold the kidney in place within the body Symptoms of intermittent pain in the renal region relieved by lying down, appear to result 4 9  Accessory renal vessels Usually the inferior vessels degenerate as superior ones take over the blood supply and venous drainage Failure of these vessels to degenerate results in accessory renal arteries and veins (known as polar arteries and veins) when they enter/exit the poles of the kidneys). Variations in the number and position of these vessels occur in ≈ 25% of people 5 0 Pain in the para renal region The close relationship of the kidneys to the psoas major muscles explains why extension of the hip joints may increase pain resulting from inflammation in the pararenal areas. These muscles flex the thighs at the hip joints Renal colic: is commonly caused by kidney stone and begins in the loin (flank region) and often radiated to the groin ( inguinal region) the kidneys are supplied by T10 – L1 spinal segments, the pain is referred to the flank along 6 the subcostal nerve and to the groin along the 7 ilioinguinal nerve Renal Pain Varies from a dull ache to a severe pain that may radiate downward into the lower abdomen. can result from stretching of the kidney capsule or spasm of the smooth muscle in the renal pelvis. The afferent nerve fibers pass through the renal plexus around the renal artery and ascend to the spinal cord through the lowest splanchnic nerve in the thorax and the sympathetic trunk. 6 enter the spinal cord at the 8 level of T12. Kidney transplantation The iliac fossa on the posterior abdominal wall is the usual site chosen for transplantation of the kidney. n The fossa is exposed through an incisio in the anterior abdominal wall just above the inguinal ligament. The iliac fossa in front of the iliacus muscle is approached retroperitoneally.  The kidney The renal artery is anastomosed end-to-end to the is positioned internal and iliac artery and the renal vein is anastomosed the vascular end-to-side to anastomosis the external iliac vein constructed.  Anastomosis of the branches of the internal iliac 6 arteries on the two sides is sufficient so that the 9 pelvic viscera on the side of the renal arterial 3. Ureters are thick-walled, expandable muscular ducts with a narrow lumen connect the kidneys to the urinary bladder carry urine from the kidneys to the urinary bladder is about 25 - 30 cm long and around 3–6 mm in diameter retroperitoneal structure Each ureter is continuous above with the funnel-shaped renal pelvis has two parts: 1.the abdominal part 2. the pelvic part they pass over the pelvic brim, thus leaving the As the ureters cross the bifurcation of the common 2 5 abdomen and entering the lesser pelvis iliac The ureters 1. The abdominal part constitute the upper half each ureter is about 12.5 cm long and 5 mm wide Closely adhere to the parietal peritoneum and are retroperitoneal throughout their course descends almost vertically, y anterior to the psoas major muscle, to the tips of the transverse processes of the lower lumbar vertebrae and enter the pelvis As the right ureter descends, it is closel related to the IVC, 2 6 2 7 Relations, right ureter Anteriorly: the duodenum the terminal part of the ileum the right colic and ileocolic vessels the right testicular or ovarian vessels and the root of the mesentery of the small intestine Posteriorly: the right psoas muscle, which separates it from the lumbar transverse processes, 2 genitofemoral nerve 8 the bifurcation of the Relations, left ureter Anteriorly: the sigmoid colon and sigmoid mesocolon, the left colic vessels the left testicular or ovarian vessels Posteriorly: the left psoas muscle, which separates it from the lumbar transverse 5 8 processes, Constrictions of ureter 1.At the junction of renal pelvis and ureter 2.As it crosses the pelvic brim and common iliac artery 3.As it joins the urinary bladder Potential sites of obstruction of urinary calculi 5 9 Blood supply of the uretersupply a. Arterial - Supplied by multiple arteries through out course - the abdominal part: the renal arteries with less constant branches arising from the testicular or ovarian arteries the abdominal aorta, and the common iliac arteries 6 0  Arterial supply of both abdominal and pelvic part of the ureters 6 1 Venous drainage Veins from the ureters accompany the arteries and have corresponding names drain into the renal and gonadal veins Lymph drainage: sequentially, from superior to inferior, drain into: the lumbar (caval/aortic) common iliac nodes (abdominal part) the external and internal iliac nodes (pelvic part) 6 2 Innervation of the ureters The nerves to the ureters: derive from adjacent autonomic plexuses (renal, aortic, superior and inferior hypogastric ). The ureters are superior to the pelvic pain line Visceral afferent fibers (pain) follow sympathetic fibers to T11- L2 spinal cord segments Ureteric pain is usually referred to the ipsilateral 6 3 lower quadrant of the abdomen, especially to  the surface marking of the ureter is a line joining a point 5 cm lateral to the L1 spinous process and the posterior superior iliac spine. The ureters occupy a sagittal plane that intersects the tips of the transverse processes of the lumbar vertebrae 4 1 Clinical considerations The ureters Ureteric are expansile calculi muscular tubes that dilate if obstructed Acute obstruction usually results from a ureteric calculus The symptoms and severity depend on: the location type, and size of the calculus on whether it is smooth or spiky small calculi usually causes 6 little or no pain, larger ones 5 produce severe pain  The obstruction may occur anywhere along the ureter, but it occurs most often at the three sites constrictions 1.at the junction of the ureters and renal pelvis 2.As they cross the external iliac artery and pelvic brim 3.during their passage through the wall of the urinary bladder Ureteric calculi may be removed by: open surgery endoscopy (endourology) Lithotripsy - uses shock waves to break up a stone into small fragments that can be passed in the urine. 6 6 THE END! 7 1 THANK YOU