surgical anatomy of kidney and ureter

PrashantJrLlrmChauha 12,177 views 165 slides Dec 10, 2018
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About This Presentation

surgical anatomy of kidney and ureter


Slide Content

“SURGICAL ANATOMY OF KIDNEY AND URETER” Chairperson : Prof. Dr. Keshavamurthy R Co-chairperson : Dr. Vishwanath R Presenter : Dr. Prashant Kr Chauhan

INDEX Embryology Anatomy Gross Microscopic Coverings of the kidney Orientation of the kidney Position of the kidney Surface marking Relations of the kidney Blood supply of kidney Lymphatic drainage Nerve supply

EMBRYOLOGY OF KIDNEY Three sets of structures appear and then regress in succession ; the pronephros , the mesonephros and the metanephros which persists to form the definitive kidney.

The mesonephric (or Wolffian ) duct in adult is represented by: the duct of the epididymis the vas deferens and the ejaculatory duct the efferent ductules of the testis the appendix of the epididymis

The mesonephric duct also gives rise to the ureteric bud in both sexes. superiorly it forms the ureter, the pelvis of the ureter, the major and minor calyces and the collecting ducts Inferiorly this is absorbed into the bladder to become the trigone and part of the urethra

The metanephros is initially a pelvic organ, from weeks 6 to 9 of gestation there is progressive development and the kidneys ascend. ASCENT OF THE KIDNEY

In subsequent development of the embryo, differential growth of the abdominal wall causes the kidney to ascend to the lumbar region. The metanephros , at first, receives its blood supply from the lateral sacral arteries, but with its ascent, higher branches of the aorta take over the supply. The definitive renal artery represents the lateral splanchnic branch of the aorta at the level of the second lumbar segment.

Significance : Fusion of the lower poles of metanephric tissue results in a horseshoe kidney and inferior mesenteric artery(at level of L3) alters the ascent and rotation of the developed kidneys. Failure of development or interaction between the ureteric bud and metanephros have been implicated in congenital anomalies such as renal dysplasia and multicystic dysplastic kidneys.

When a kidney is located on the side opposite that in which its ureter inserts into the bladder, the condition is known as crossed ectopia. Ninety percent of crossed ectopic kidneys are fused to their ipsilateral mate.

Crossed renal ectopia with fusion

Crossed renal ectopia without fusion

Anatomy The kidneys are paired ovoid reddish-brown retroperitoneal organs situated in the posterior part of the abdomen on each side of the vertebral column. Each kidney is of a characteristic shape, having a superior and an inferior pole, a convex border placed laterally, and a concave medial border. The medial border has a marked depression the hilum containing the renal vessels and the renal pelvis.

At the concave medial margin of each kidney is a vertical cleft, the renal hilum , where the renal artery enters and 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. Kidneys Anatomy: Hilum

MACROSCOPIC ANATOMY measures 10 to 12 cm in length( 2 & half vertebral body length ) 5.0 to 7.5 cm in width 2.5 to 3.0 cm in thickness weighs approximately 125 to 170 gm(in males) 10 to 15 gm smaller in females.

Basic Intrarenal Anatomy

Cortical Tissue On a longitudinal section, the cortex forms the external layer of renal parenchyma. The layers of cortical tissue between adjacent pyramids are named renal cortical columns of Bertin .

Renal Medulla The renal medulla is formed by several inverted cones, surrounded by a layer of cortical tissue on all sides (except at the apexes). Thus forming a renal pyramid. The apex of a pyramid is the renal papilla.

In living persons, the renal pelvis and its calyces are usually collapsed (empty). Kidneys Anatomy: Pyramids

The pyramids and their associated cortex form the lobes of the kidney. The lobes are visible on the external surfaces of the kidneys in fetuses, and evidence of the lobes may persist for some time after birth.

Pelvicalyceal System A minor calyx is defined as the calyx that is in immediate apposition to a papilla. The renal minor calyces drain the renal papillae and range in number from 5 to 14 (mean 8). A minor calyx may be single (drains one papilla) or compound (drains two or three papillae). The polar calyces often are compound, markedly in the superior pole.

The renal pelvis receives two or three major calyces (calyces), each of which divides into two or three minor calyces . Each minor calyx is indented by the renal papilla, the apex of the renal pyramid, from which the urine is excreted. Calyces And Papillas

The minor calyces may drain straight into an infundibulum or join to form major calyx, which subsequently will drain into an infundibulum. Finally, the infundibulam , which are considered the primary divisions of the pelvicalyceal system, drain into the renal pelvis.

Classification of the Pelviocalyceal System ( Sampaios Classification ) Group A This group is composed of pelviocalyceal systems that present two major calyceal groups (superior and inferior) as a primary division of the renal pelvis and a midzone calyceal drainage dependent on these two major groups.

Group A Type A-I In which the kidney midzone is drained by minor calyces that are dependent on the superior or on the inferior calyceal groups, or even on both superior and inferior calyceal groups, simultaneously Type A-II In which the kidney midzone is drained by crossed calyces, one draining into the superior calyceal group and another draining into the inferior calyceal group, simultaneously.

Classification of the Pelviocalyceal System ( Sampaios Classification ) Group B This group is composed of pelviocalyceal systems that present the kidney midzone ( hilar ) calyceal drainage independent of both the superior and the inferior calyceal groups.

Group B Type B-I In which the kidney midzone is drained by a major calyceal group, independent of both the superior and the inferior groups. Type B-II In which the kidney midzone is drained by minor calyces (one to four) entering directly into the renal pelvis.

anteroposterior orientation of the calyces This unit is rotated anteriorly , such that the posterior calyces are about 20 degrees behind the frontal plane and the anterior calyces are 70 degrees in front of the frontal plane. The calyceal pairs are rotated posteriorly , with the posterior calyces 70 degrees behind the frontal plane and appearing medial and with the anterior calyces 20 degrees in front of the frontal plane and appearing lateral . BRÖDEL TYPE KIDNEY HODSON-TYPE KIDNEY

Hodson type BRODEL TYPE

The posterior calyces are lateral, and the anterior calyces are medial in the Brodel type kidney. Most right kidneys have a Brödel -type orientation (posterior calyces are lateral), and most left kidneys have a Hodson -type orientation (posterior calyces are medial)

Significance : A serious and troublesome complication of endoscopic intrarenal operation is bleeding from an injured vessel. To avoid such injury, the position of the intrarenal vascular structures must be known in relation to the collecting system.

Not Recommended

Recommended

Microscopic Anatomy The functional renal unit is the nephron , which is composed of the following: The renal corpuscle: glomerulus and Bowman capsule Proximal convoluted tubules (PCT, located in the renal cortex) Descending loop of Henle (LOH)

Ascending limb (which resides in the renal medulla, leading to the thick ascending limb) Thick ascending limb Distal convoluted tubule Collecting duct (which opens into the renal papilla)

Coverings Of The Kidney Fibrous capsule Perinephric fat Renal/ Gerota’s fascia Paranephric fat

Fibrous capsule Composed of fibrous tissue and smooth muscle Forms firm smooth investment for kidney. Will be sharply deflected over margin of a subcapsular collection/mass with flattening and compression of the kidney

Surgical importance : Subcapsular nephrectomy done inside this capsule. E.g. xanthomatous granulomatous nephritis. In case of partial nephrectomy it gives strength for suturing.

Perinephric fat (the perirenal fat capsule) surrounds the kidneys and their vessels as it extends into their hollow centers, the renal sinuses. Perinephric Fat

GEROTAS FASCIA

The kidneys, suprarenal glands, and the perinephric fat surrounding them are enclosed (except inferiorly) by a condensed, membranous layer of renal fascia , which continues medially to ensheath the renal vessels, blending with the vascular sheaths of the latter. Renal Fascia

Inferomedially , a delicate extension of the renal fascia is prolonged along the ureter as the periureteric fascia.

Significance : The Gerota fascia is closed superiorly and laterally and serves as an anatomic barrier to the spread of malignancy and a means of containing perinephric fluid collections. It is open inferiorly, perinephric fluid collections can track inferiorly into the pelvis without violating the Gerota fascia and may lead to pelvic abscess.

Superiorly, the renal fascia is continuous with the fascia on the inferior surface of the diaphragm (diaphragmatic fascia); thus the primary attachment of the suprarenal glands is to the diaphragm. Inferiorly, the anterior and posterior layers of renal fascia are only loosely united. Renal Fascia, contd.

External to the renal fascia is paranephric fat (or the pararenal fat body), the extraperitoneal fat of the lumbar region that is most obvious posterior to the kidney The renal fascia sends collagen bundles through the paranephric fat. Paranephric fat

The collagen bundles, renal fascia, and perinephric and paranephric fat, along with the binding provided by the renal vessels and ureter, hold the kidneys in a relatively fixed position (T12-L3) However, movement of the kidneys occurs during respiration and when changing from the supine to the erect position, and vice versa.

Location and long axis

Orientation Of Kidneys The kidneys lie on the Psoas muscles. Thus the longitudinal axis of the kidneys are oblique , with the upper poles more medial than the inferior poles.

The medial aspect of each kidney is rotated anteriorly at an angle of approximately 30 degrees.

The upper pole of the kidney lies posteriorly than the inferior poles.

Position Of Kidneys Position of the kidney within the retroperitoneum varies during different phases of respiration, body position, and presence of anatomic anomalies. For example, the kidneys move inferiorly approximately 3 cm (one vertebral body) during inspiration and during changing body position from supine to the erect position. If the kidney moves more than it then the kidney called as Nephroptosis / Renal ptosis / Floating kidney . The position of the kidneys in the supine end-expiration is described.

Because of the inferior displacement of the right kidney by the liver, the right kidney sits 1 to 2 cm lower than the left kidney. The right kidney resides in the space between the top of the 1st lumbar vertebra to the bottom of the 3rd lumbar vertebra. The left kidney occupies a space between the 12th thoracic vertebra and the 3rd lumbar vertebra.

The adult kidney’s lateral contour might have a focal renal parenchymal bulge known as Dromedary hump more common on left side. It is physiological and caused by downward pressure from the liver or the spleen.

RELATIONS OF THE KIDNEY

Ribs: The left kidney is higher than the right kidney. The posterior surface of the right kidney is crossed by the 12th rib. The left kidney crossed by the 11th and 12th ribs.

Significance : When the lower ribs are fractured during trauma, associated renal lacerations could occur.

Diaphragm: ● The posterior surface of the diaphragm attaches to the extremities of the 11th and 12th ribs. ● Close to the spine, the diaphragm is attached over the posterior abdominal muscles and forms the medial and lateral arcuate ligaments on each side. ● Thus the posterior aspect of the diaphragm (posterior leaves) arches as a dome above the superior pole of the kidneys, on each side.

Significance : The upper poles of the kidneys come close to the diaphragm and underlying pleural cavity containing the lungs; thus any violations of the diaphragm during excision of large renal masses could lead to pleural tears and pneumothorax .

Pleura: Generally, the posterior reflection of the pleura extends inferiorly to the 12th rib The lowermost lung edge lies above the 11th rib (at the 10th intercostal space).Regardless of the degree of respiration (mid- or full expiration), the risk of injury to the lung from a 10th intercostal percutaneous approach to the kidney is prohibitive. The pleura is traversed without symptoms in most intercostal approaches.

Significance : When performing an intrarenal access by puncture, the endourologist may consider that the diaphragm is traversed by all intercostal punctures, and possibly by some punctures below the 12th rib .

Significance : Any intercostal puncture should be made in the lower half of the intercostal space, in order to avoid injury to the intercostal vessels above.

KIDNEY RELATIONSHIPS WITH LIVER AND SPLEEN The liver on the right side and the spleen in the left, may be posterolaterally positioned at the level of the suprahilar region of the kidney, because at this point, these organs have their larger dimensions Therefore, one may remember that a kidney puncture performed high in the abdomen has little space for the needle entrance.

Significance : If the intrarenal puncture is performed when the patient is in mid- or full inspiration, the risk to the liver and spleen is increased. This knowledge is particularly important in patients with hepatomegaly or splenomegaly , on whom a computed tomography (CT) scan should be performed before puncturing the kidney

The parietal peritoneum bridging the upper pole of the right kidney to the liver forms the hepatorenal ligament . Therefore excessive downward traction of the right kidney may cause capsular tear of the liver and may lead to excessive intraoperative bleeding.

The parietal peritoneum bridging the upper pole of the left kidney to the spleen forms the splenorenal ligament . If excessive downward pressure is applied to the left kidney, splenic capsular tears may occur, leading to hemorrhage from the spleen.

KIDNEY RELATIONSHIPS WITH ASCENDING AND DESCENDING COLONS The ascending colon runs from the ileocolic valve to the right colic flexure (hepatic flexure), where it passes into the transverse colon. The hepatic colic flexure (hepatic angle), lies anteriorly to the inferior portion of the right kidney.

The descending colon extends from the left colic flexure ( splenic flexure) to the level of the iliac crest. The left colic flexure lies anterolateral to the left kidney.

Significance : It is important to consider the position of the retroperitoneal ascending and descending colons. Normal relation Retrorenal Colon

Retrorenal Colon On routine abdominal CT scan examinations, the retroperitoneal colon is found lying in a posterolateral or even a postrenal position which is referred to as Retrorenal colon. In these cases, it is at great risk of being injured during the intrarenal percutaneous approach. This event ( retrorenal colon) more commonly occurs with regard to the inferior poles of the kidneys.

It is demonstrated by CT scan that, when the patient is in the supine position, the retrorenal colon was found in 1.9% of the cases. Nevertheless, when the patient assumes the prone position (the more frequent position used for percutaneous access to the kidney) the retrorenal colon was found in 10% of the cases.

BLOOD SUPPLY OF KIDNEYS

RENAL ARTERIES The renal arteries arise at the level of the intervertebral disc between the L1 and the L2 vertebrae. The longer right renal artery passes posterior to the inferior vena cava.

Typically, each artery divides close to the hilum into five segmental arteries that are end arteries (i.e . they do not anastomose significantly with other segmental arteries, so that the area supplied by each segmental artery is an independent, surgically resectable unit or renal segment). Renal Arteries

INTRARENAL ARTERIAL ANATOMY

Vascular Supply Renal artery  Interlobar arteries  Arcuate arteries  Interlobular arteries  Afferent arteries  Glomeruli  Efferent arterioles Peritubular plexus   Arcuate veins

Significance : Segmental end arteries that do not anastomose significantly with other segmental arteries. Therefore occlusion or injury to a segmental branch will cause segmental renal infarction . The posterior segmental artery from the posterior division passes posterior to the renal pelvis while the others pass anterior to the renal pelvis. If the posterior segmental branch passes anterior to the ureter, PUJO may occur .

There is a longitudinal avascular plane ( line of Brodel ) between the posterior and anterior segmental arteries just posterior to the lateral aspect of the kidney through which incision results in significantly less blood loss. During anatrophic nephrolithotomy incision is made through this avascular plane.( Boyce procedure )

Anatrophic Nephrolithotomy

During their ascent to their final site, the embryonic kidneys receive their blood supply and venous drainage from successively more superior vessels. Usually the inferior vessels degenerate as superior ones take over the blood supply and venous drainage. Accessory Renal Vessels

Accessory Renal Vessels 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 approximately 25% of people.

Significance : Supernumerary renal arteries are the most common variation, with reports of up to five arteries, especially on the left side. The main renal artery may manifest early branching after originating from the abdominal aorta and before entering the renal hilum . These prehilar arterial branches should be detected in patients undergoing evaluation for donor nephrectomy .

Dietl’s crisis- intermittent PUJO, often associated with an aberrant vessel to the lower pole of the kidney

RENAL VENOUS SYSTEM

The intrarenal veins, unlike the arteries, do not have a segmental model. In contrast to the arteries, there is free circulation throughout the venous system, providing ample anastomoses between the veins. These anastomoses , therefore, prevent parenchymal congestion and ischemia in case of venous injury.

The small veins of the cortex, called stellate veins, drain into the interlobular veins that form a series of arches. Within the kidney substance, these arches are arranged in arcades, which lie mainly in the longitudinal axis.

There are usually three systems of longitudinal anastomotic arcades. Between the stellate veins (more peripherally) called first order Between the arcuate veins (at the base of the pyramids) called as second order Between the interlobar ( infundibular ) veins (close to the renal sinus) which are called as third order veins.

These finally drain to form the Renal Vein which drains into IVC. The right and left renal veins lie anterior to the right and left renal arteries.

VENOUS DRAINAGE

The longer left renal vein receives the left suprarenal vein, the left gonadal (testicular or ovarian) vein, and a communication with the ascending lumbar vein, then passes anterior to the aorta. Each renal vein drains into the inferior vena cava. Ascending lumbar vein Renal Veins

Significance : The left renal vein traverses the acute angle between the superior mesenteric artery anteriorly and the aorta posteriorly . In thin adolescents, the left renal vein may get compressed between the superior mesenteric artery and aorta, causing nutcracker syndrome.

Nutcracker syndrome

Lymphatic drainage Interstitial fluid leaves the kidney by either a superficial capsular or a deeper hilar network. Renal lymphatics are embedded in the periarterial loose connective tissue around the renal arteries and are distributed primarily along the interlobular and arcuate arteries in the cortex.

Left lymphatic drainage primarily to left lateral para -aortic lymph nodes (between the inferior mesenteric artery and diaphragm), with occasional additional drainage into the retrocrural nodes or directly into the thoracic duct above the diaphragm. Right renal lymphatic drainage primarily goes into the right interaortocaval and right paracaval lymph nodes (between common iliac vessels and diaphragm), with occasional additional drainage from the right kidney into the retrocrural nodes or the left lateral para -aortic lymph nodes.

LYMPHATICS OF KIDNEYS

Nervous System Of Kidney The kidney can function well without neurologic control, as evidenced by the successful function of transplanted kidneys. Sympathetic preganglionic nerves originate from the 8th thoracic through 1st lumbar spinal segments. Parasympathetic fibers from the vagus nerve travel with the sympathetic fibers to the autonomic plexus along the renal artery.

NERVE SUPPLY OF KIDNEYS

URETERS

index Embryology Anatomy Gross Microscopic Course of the ureter Normal constrictions of ureter Blood supply of ureter Lymphatic drainage Nerve supply

Embryology At the fifth week of development, the ureteric bud arises as a diverticulum from the mesonephric ( Wolfian ) duct. The bud grows laterally and invades the center of the metanephrogenic blastema , the primordial renal tissue. From 28 to 35 days of development, the ureter is patent, probably as a result of the mesonephros producing urine which fills the tube.

From 37 to 40 days of development the ureter loses its lumen. At 40 days of development the ureter regains a lumen. Starting at the midpoint and progressing in both directions toward the developing kidney and the urogenital sinus, the lumen of the ureter reforms. The last segments of the ureter to gain a lumen are at either end (kidney or urogenital sinus)

Gross Anatomy The ureters are muscular ducts (25 - 30 cm long) with narrow lumina that carry urine from the kidneys to the urinary bladder. They run inferiorly from the apex of the renal pelves at the hila of the kidneys, passing over the pelvic brim at the bifurcation of the common iliac arteries. They then run along the lateral wall of the pelvis and enter the urinary bladder. The abdominal parts of the ureters adhere closely to the parietal peritoneum and are retroperitoneal throughout their course

Microscopic Anatomy Of The Ureter The ureter consists of three distinct layers: the innermost mucosa. the middle muscular layer the outer adventitia.

mucosa The mucosa consists of transitional epithelium, which has four to six layers of cells when the ureter is contracted. These cells contain keratin precursors that is responsible for the waterproof property of this layer. The mucosa also contains many longitudinal folds that give the empty ureter a characteristic stellar outline.

Muscle layer The muscular wall of the ureter consists of two longitudinal layers separated by a middle circular layer that may not be distinct from each other. These smooth muscle layers are contiguous with the smooth muscle covering the minor renal calyces, where the pacemaker is located to initiate the rhythmic peristalsis to deliver urine.

adventitia The adventitia, consists of a dense network of collagen and elastic fibers, including many blood vessels and unmyelinated nerve fibers among them. In a normal kidney, the UPJ does not differ histologically from the renal pelvis. However , in PUJO , the longitudinal muscle fibers are significantly increased with more collagen deposits around the muscle fibers in addition to attenuation of muscle bundles.

Variations in anatomy and its significance Duplication of the ureter : Y shaped duplication - represents divergence of the ureteric bud before meeting the metanephric blastema .

Weigert - Meyer law : In Complete duplication the orifice of the lower pole ureter occupies a more cranial and lateral position.In general, the upper pole ureter drains less renal parenchyma.

Ureterocele : A ureterocele is a sacculation or cystic dilatation of the terminal ureter. It results from incomplete canalization between the urogenital sinus and ureteric bud. It may cause obstruction of an ipsilateral or contralateral ureteral orifice or the bladder outlet.

Ectopic ureteral orifice : An ectopic ureteral orifice often occurs in the upper pole of duplicated systems but can also occur in single ureters . The orifice is caused by delayed or failed separation of the ureteral bud from the mesonephric ducts.

Ectopic ureteral orifice Posterior urethra, seminal vesicle, and ductus deferens are common locations for ectopic ureteral orifices in males, making urinary tract infection and epididymitis common presenting features. Ectopic ureteral orifices in females tend to be in the urethra, vagina, or perineum, making total incontinence a presenting symptom. MALE FEMALE

Ectopic Ureteral Orifice Male Female

Retrocaval ureter The right ureter may pass posterior to the inferior vena cava before hooking medially anterior to it and then resuming its normal course to the pelvis. This abnormality is a vascular rather than ureteral embryologic phenomenon, with the subcardinal vein persisting and becoming the inferior vena cava rather than the supracardinal vein. For this reason, the term preureteral inferior vena cava has been favored in some texts. The proximal ureter is often dilated in this setting.

Development Of IVC

Course of the Ureter The ureter is arbitrarily divided into 3 parts proximal (upper) middle (over the sacrum) distal (lower) The surface anatomy of the ureter corresponds to a line joining a point 5 cm lateral to the L1 spinous process and the posterior superior iliac spine.

Significance : The close relationship of the ureter with the terminal ileum, appendix, right and left colons, makes it susceptible for encroachment of inflammatory and malignant processes, resulting in clinical presentations ranging from microhematuria to ureteral obstruction or even fistulae.

The close proximity of the ureter to the uterine vessels is the cause of ureteral injuries during gynecologic procedures. In the case of vaginal surgery, there is a high risk for injury especially for the left ureter that crosses the anterior vaginal fornix closer than the right ureter.

Near the bladder, the terminal ureter is enveloped by a muscular layer, the Waldeyer sheath, which coalesce with those of the detrusor muscle, therefore reflux of urine from the bladder to the ureter is prevented during increased intravesical pressure, such as during micturition . Paquin ratio : Paquin recommended a tunnel length five times the diameter of the ureter to prevent vesicoureteral reflux (VUR) during ureteral reimplant .

INTRAMURAL URETER

The ureters are normally constricted to a variable degree in three places: at the junction of the ureters and renal pelvis, ( 2)where the ureters cross the iliac vessels, ( 3)during their passage through the wall of the urinary bladder. URETER: CONSTRICTED AREAS

Significance : These constricted areas are potential sites of obstruction by ureteric (kidney) stones. Because of these constrictions , there is increased risk of perforation at these sites.

Proximal ureter – Branches arising medially from renal arteries, testicular, ovarian arteries, the abdominal aorta, and the common iliac arteries. Mid ureter : Branches arising posteriorly from common iliac arteries. Distal ureter : Branches arising laterally from superior vesical artery. URETER BLOOD SUPPLY

BLOOD SUPPLY OF URETER

Veins draining the abdominal part of the ureters drain into the renal and gonadal (testicular or ovarian) veins. URETERS: VENOUS DRAINAGE

Significance : Thus endoureterotomy should be performed laterally in the proximal ureter, anteriorly in the mid-portion and medially in the distal ureter. In open pyeloplasty spatulation of ureter is done on lateral side.

The lymphatic vessels of the ureters join the renal collecting vessels or pass directly to right or left lumbar ( caval or aortic) lymph nodes and the common iliac lymph nodes. Lymph drainage from the pelvic parts of the ureters is into the common, external, and internal iliac lymph nodes. URETERS: LYMPHATIC DRAINAGE

Nerve supply of ureter The ureter receives a rich autonomic nerve supply that originates from the celiac, aortorenal , and mesenteric ganglia, together with the superior and inferior hypogastric (pelvic) plexuses afferent nerves from the upper portion of the ureter reach the spinal cord with the sympathetic fibers between T11 and L1 and those from the lower ureter travel via the pelvic plexus between S2 and S4.

These fibers conduct afferent sensory stimuli from the ureters and have a minor, if any, role in the control of ureteral motility.

Significance : This is because excised portions of the ureter continue to contract without nervous control and denervation of the lower portion of the ureter does not result in reflux .

Reference : Campbell -Walsh urology 11 th edition Human embryology Inderbir Singh 8 th edition Hinman’s Atlas of Urosurgical anatomy 2 nd edition Smith’s Textbook of Endourology 3 rd Edition

Thank You Anatomy of course does not change, but our understanding of anatomy and its clinical significance does change. – Frank H. Netter, MD