SURGICAL ANATOMY OF ADRENAL GLAND AND KIDNEY

Dr. Kangjam Sholay Meitei (M.Ch. Student)

ADRENAL GLAND

• Anatomic Relationships– 3-5 cm in transverse dimen– Weight- 5 g– Grossly- yellow orange– Enclosed within the Gerota’s fascia– Rt Adrenal-more superior, pyramidal shape, directly cranial

to upper pole of kidney, surrounding structures- liver, duodenum, IVC, retrocaval extension of one wing

– Lt. Adrenal- more crescentic, medial to upper pole of K, upper & ant relations- stomach, tail of pancreas, splenic vessels

Composition

• Embryologically the adrenals are distinct from kidney,• Developmental anomalies of one do not affect the other• Histologically, medulla & cortex• Medulla- chromaffin cells (neural crest origin)-secrete

catecholamines under sympth control• Cortex - 90% of gland, mesodermal origin

– 3 layers (Zona glomerulosa-mineralocorticoids,Zona fasciculata-glucocorticoids, Zona reticularis-sex steroids)

Adrenal Vessels

• Arterial- 3 sources: Inferior phrenic A, Aorta, Renal A• Venous drainage-single adrenal vein

– Rt vein drains to IVC– Lt vein joins inf. Phrenic vein and drains to left R. vein

• Lymphatic drainage- follows course of vessels and empties into para-aortic LN.

KIDNEY• Gross & Microscopic anatomy• Relations & Investing fascia• Renal Vasculature• Renal Lymphatics• Renal Collecting System• Renal Innervation

Introduction

• It serves a no. of important functions required to maintain normal physiologic function

• Maintain fluid & electrolyte balance• Maintain acid-base balance• Produce Renin (BP), Erythropoietin (RBC production), calcium

metabolism( Vit D 1,25 dihydroxyvitamin D)

Gross anatomy

• b/l paired reddish brown organs• Weight-150 g (M), 135g (F)• Dimensions :10-12 cm Vertical, 5-7cm Transverse, 3cm AP• Rt kidney-shorter & wider• Children-relatively larger, fetal lobulations• Dromedary hump-due to downward pressure from spleen or

liver

Microscopic Anatomy

• Renal sinus-vascular structures & collecting system coalesce, surrounded by fat

• Renal sinus narrows to hilum medially• Renal parenchyma-cortex & medulla• Medulla-not contiguous layer, has multiple, distinct, conically

shaped areas (pyramid)• Apex of pyramid is papilla which is cupped by minor calyx• Cortex-lighter colour, covers pyramids peripherally and extends

between pyramids as columns of Bertin• Surgical importance of Columns of Bertin- renal vessels traverse

from r. sinus to cortex- so avoid in percutaneous access to collecting system

Relations and Investing Fascia

• position in retroperitoneum varies greatly by size, degree of inspiration, body position & anatomic anomalies

• RK sits 1-2 cm lower than LK• RK-top of L1 to bottom of L3• LK- body of T12 to body of L3• Posterior-diaphragm,pleura,12th Rib• Medial-psoas ms• Lateral-quadratus lumborum, aponeurosis of transversus

abdominis ms• Surgical importance – lower pole lies lateral & ant., medial

aspect is rotated ant. 30°

Relations and Investing Fascia

• Anterior-(RK)Liver,rt. Adrenal, duodenum, hep flexure of colon -(LK)panc. tail with splenic vessels, post .gastric wall,left adrenal, spleen,splenic flexure of colon

• Gerota’s (perirenal) fascia– Encompass perirenal fat & Kidney (superior, lateral & medial)– Inferior- open potential space– Serves as anatomic barrier to malignancy & contained perinephric

fluid collection

Renal Vasculature

• Classically renal pedicle-1 RA, 1 RV at L2, Vein is ant to Artery• Renal Artery

– RRA leaves aorta with caudal slope under IVC– LRA courses directly lateral– Both RA moves posteriorly as they enter kidney, both has branches to

adrenal, R. pelvis & ureter– Splits into 4 or more segmental arteries – supplies distinct portion of

kidney with no collateral circulation (so segmental infarct)– Seg. Branches- 1 posterior,4 anterior (apical, upper, middle & lower)– Post. Seg. Br. is posterior to pelvis while others pass ant.– Surgical importance-longitudinal avascular plane betw post & ant seg.

A , lies posterior to lateral aspect

Segmental A in renal sinus lobar A interlobar A(columns of Bertin close to minor calyceal infundibula) arcuate arteries at base of pyramid interlobular A Afferent A to glomeruli Efferent A and continuous to cap network around urinary tubules in cortex or descending into renal medulla as vasa recta

Renal Veins

• Interlobular veins arcuate v interlobar v lobar v segmental v 3-5 venous trunks combined to form renal

vein• Venous drainage communicates freely through venous collars

around the infundibula• RV is located directly ant. to RA• Rt.RV -2-4cm long, enters IVC (rt lat to posterolat edge)• Lt.RV-6-10cm long, enters IVC (lt lat aspect)• Lt. RV receives Lt Adrenal V, Lumbar V, Lt gonadal V.

Common anatomic variants

• Vascular variations in 25-40%• Supernumerary renal arteries

– upto 5 A reported, more on Left– Lower pole A cross ant to IVC(Rt) or ant to collecting system– More common in ectopic kidney

• Supernumerary renal vein-less common

Renal lymphatics

• Follow blood vessels in Columns of Bertin and form several lymphatic trunks in R. sinus and exits in hilum (receives branches from renal capsule,perinephric tissues,renal pelvis and upper ureter) and drains into hilar LN

• On lft,primary drainage is into left lateral paraaortic LN, retrocrural nodes or thoracic duct.

• On Rt, drainage into rt interaortocaval & rt paracaval LN

Renal Collecting System

• Microscopic Anatomy from Glomerulus to Collecting System– Renal collecting system originates in renal cortex at glomerulus– Glomerular cap network & Bowman’s capsule form renal corpuscle or

Malpighian corpuscle– Glomerular cap network is covered by podocytes– Bowman’s capsule-PCT(thick cuboidal epith covered by dense

microvilli)-loop of Henle-DCT-collecting tubule-collecting duct-emties into apex of medullary pyramid, the renal papilla.

Renal Papillae, Calyces and Pelvis

• Renal papillae(tip of medullary pyramid) constitute first gross structure of renal collecting system

• 7-9 papillae per kidney (4-18)• Papillae alligned in 2 longitudinal (ant & post) rows, 90° to each

other• Each papillae cupped by minor calyx-narrows to infundibulum-

infundibuli combine to form 2-3 major calyceal branches (upper, middle & lower pole calyces)- combine to form renal pelvis(intra or extrarenal pelvis)- pelvis narrows to UV junction

• Compound calyx (upper & lower poles) due to renal pyramid fusion,reflux into parenchyma common (scarring)

Anatomic variations of renal collecting system

• Number of calyces, diameter of infundibuli, size of renal pelvis• It is difficult to distinguish pathologic from normal based on

anatomy alone• Demonstrated dysfunction is needed to make diagnosis of

pathologic anatomic formation

Renal Innervation

• Sympathetic preganglionic nerves- originates from T8-L1 spinal segments & travel to celiac and aorticorenal ganglia-

postganglionic fibres via autonomic plexus around RA.• Parasympathetic fibres from vagus nv, travel via sympth fibres

to autonomic plexus• 1° function of Autonomic-vasomotor (sympth-vasoconstriction, parasympth-vasodilatation)• Kidneys function well without neurologic control(transplant K)

THANK YOU