Lymph drainage It is to the following lymph node stations: (cid:142)(cid:3) Cardiac (right and left) (cid:142)(cid:3) Greater and lesser curvature (cid:142)(cid:3) Suprapyloric and i nfrapyloric (cid:142)(cid:3) Left gastric artery, common hepatic artery, coeliac artery, sp lenic artery, middle colic artery (cid:142)(cid:3) Hilum of the spleen, posterior of the pancreas, root of the mesentery (cid :142)(cid:3) Para-aortic. The small intestine This comprises: (cid:142)(cid:3) Duodenum (cid:142)(cid:3) Jejunum (cid :142)(cid:3) Ileum. The duodenum is retroperitoneal and joins the jejunum at the duodeno- j ejunal flexure. The jejunum and ileum are both suspended from the posterior ab- dominal wall by a double fo ld of peritoneum containing the blood supply and venous drainage \200\224the mesentery. Its attachment is about 15cm long and it lies obliquely from the duodenojejunal flexure to the ileocaecal junction. The 20+feet (about 7m) of the small bowel attached to such a small ba se are therefore convoluted. THE DIGESTIVE SYSTEM1 69 As jejunum runs into ileum the features change. Although both have large surface areas inte rnally to aid absorption, the circular folds of mucous membrane decrease in number and size in the ileum and are almost completely absent in the lower ileum so the wall feels thinner . Throughout the small intestine aggregations of lymph follicles are present. These are mor e marked in the ileum and are called Peyer \200\231s patches. They occur on the anti-mesent eric border. Another difference is that mesen- teric fat is less abundant near the intestin al wall in the jejunum so that the vessels to the gut can be seen with mesenteric transpare nt windows between them. Blood supply (cid:142)(cid:3) Arterial: the superior mesenteric artery crosses the third pa rt of the duodenum to enter the root of the mesentery and pass downward towards the right i liac fossa. It gives off several jejunal and ileal arteries, which divide and reunite to su pply the small bowel. In doing so, they form a series of arterial arches and arcades. so on e or more of the main trunks may be ligated without affecting the blood supply. (cid:142)(cid:3) Venous: the veins drain the gut along the arterial pathways and empty into the superior mesenteric vein which joins the portal vein on its way to the liver. Practical hints (cid:142)(cid:3) The duodenojejunal flexure is a site which must always be carefully examined in patients with deceleration injuries because disruption can occur. (cid:142)(cid:3) The fact that the blood supply of the small bowel is organized in arches a nd arcade allows to ligate one of the main trunks without affecting the blood supply. This is done when constructing an ileal pouch for anas- tomosis to the rectum in patients with i nflammatory bowel disease and familial adenomatous polyposis (see Restorative proctocolecto my). The large bowel This is approximately 1.5m long. It comprises of: (cid:142)(cid:3) Appendix (cid:142)(cid:3) Caecum (cid:142)(cid:3) Ascending colon (cid:142)(cid:3) Hepatic flexure (cid:142)(cid:3) Transverse colon (cid:142)(cid:3) Splenic flexure (cid:142)(cid:3) Descend ing colon (cid:142)(cid:3) Sigmoid colon (cid:142)(cid:3) Rectum (cid:142)(cid:3) Anus. The lumen is wide in the caecum and ascending colon but gradually narrows towards the sigmoid colon. Structure It has a peritoneal coat complete over the caecum, appendix, transverse colon and sigmoid colon but incomplete elsewhere. There are small CHAPTER 3 Anatomy for surgeons 70 pouches of peritoneum filled with fat over all of the colon \200\224appendices epiploicae. The outer muscular coat is disposed in three longitudinal bands \200\224the taenia coli. Th ese converge upon the root of the appendix proximally. At the other end they become continu ous with the longitudinal layer of the rectum. They are shorter than the colon so its wall becomes puckered into sacculations \200\224colonic haustrations. Caecum The ileum terminates in a slit-like opening \200\224the ileocaecal valve. The blind- ending portion below this level is the caecum. It may lie free or be attached to the right iliac fossa by peritoneal folds. Relations (cid:142)(cid:3) Inferior: lateral half of ingui nal ligament (cid:142)(cid:3) Anterior: greater omentum, coils of ileum, anterior abdominal wall (cid:142)(cid:3) Posterior: iliacus and psoas. Colon The ascending and descending com ponents are partly retro-peritoneal. The transverse and sigmoid colon are suspended on mese nteries. Transverse colon The middle portion lies below the umbilicus. Superiorly lies the greater c urvature of the stomach, liver, and gall bladder. Posteriorly from right to left are the se cond part of the duodenum, the pancreas, loops of small bowel and the spleen. Anteriorly is the greater omentum. Descending colon This begins at the splenic flexure and ends at the beginning of the sigmoi d colon. Relations (cid:142)(cid:3) Anterior: jejunum, lower part of anterior abdominal wai l (cid:142)(cid:3) Posterior: left kidney, psoas, quadratus lumborum, iliacus Sigmoid colon This begins at the pelvic brim and ends at the level of the 3rd sacral ver- tebra. It is m obile and variable in length. It is related superiorly to loops of small bowel. Blood supply (cid:142)(cid:3) Caecum and appendix: from the superior mesenteric and ileocol ic arteries (cid:142)(cid:3) Ascending colon: from ileocolic and right colic arteries (cid:142)(cid:3) Transverse colon/flexures: from the right middle and left colic arteries (cid:142)(cid:3) D escending colon: left colic artery (cid:142)(cid:3) Sigmoid and upper rectum: left colic, s uperior rectal arteries. Lymphatic drainage This is along the arterial supply. Nodes are si tuated: (cid:142)(cid:3) On the bowel surface (cid:142)(cid:3) Between the layers of the me socolon (cid:142)(cid:3) Along the branches of the mesenteric arteries (cid:142)(cid:3) Alo ng the trunks of the main vessels. THE DIGESTIVE SYSTEM1 71 Marginal artery Superior mesenteric artery Middle colic artery Inferior mesenteric artery Left colic artery Right colic artery Sigmoid branches lleo-colic artery Superior rectal artery Appendix Fig. 3.12 The arterial blood supply of the large intestine. From Applied Basic Science for Basic Surgical Training, (ed. A. T. Raftery), 2000. Reproduced with permission from Churchi ll Livingstone CHAPTER 3 Anatomy for surgeons 72 The appendix Surface markings The vermiform (worm-like) appendix is an appendage of the cae cum lying in the right iliac fossa. When inflamed, maximum tenderness is classically felt o ver McBurney s point (one third of the way along a line drawn from the anterior superior il iac spine to the umbilicus). Features It is 8 \200\22310cm long and 6 \200\2238mm in girth. Its base is attached to the caecum at the point of convergence of the three taenia coli on the posteromedial wall (see McBurney s point, above) or responding to McBurney \200\231s point on the surface. It contains numerous aggregations of lymphoid tissue in its wall and has a small lumen. It is covered by peritoneum and has a well-formed mesoappendix derived from the posterior laye r of the mesentery of the lower ileum. It is in the mesoappendix that the appendicular vess els lie. Blood supply The appendicular artery is a branch of the posterior caecal from the ileocolic artery. It gives off 2 \200\2233 branches to the appendix during its course in the free cr escentic edge of the mesoappendix. Variations in position The appendix may be freely movable. Common variations in order of fr equency are: (cid:142)(cid:3) Retrocaecal (62%): sometimes extending to the right lobe of t he liver, or in the serous coat of the caecum (cid:142)(cid:3) Pelvic (34%): rectal examination may produce pain (cid:142)(cid:3) Paracae cal (2%) (cid:142)(cid:3) Preileal (1%) (cid:142)(cid:3) Retroileal (0.5%). This page intentionally left blank CHAPTER 3 Anatomy for surgeons 74 The rectum The rectum extends from the rectosigmoid junction (at the level of S3) to the pr oximal part of the anal canal (2.5cm in front of the coccyx). It is 10 \200\22315cm long. Peritoneal covering (cid:142)(cid:3) Upper third: the posterior wall is extraperitoneal. (c id:142)(cid:3) Middle third: the posterior and lateral walls are extraperitoneal. (cid:142) (cid:3) Lower third: is entirely extraperitoneal. Relations (cid:142)(cid:3) Anteriorly: Male: rectovescical pouch, bladder, prostate and seminal vescicles. The fascia of Denonvill iers separates these structures from the anterior wall of the rectum. Female: recto-uterine pouch of Douglas and the posterior wall of the vagina. (cid:142)(cid:3) Posteriorly: sacrum and coccyx. (cid:142)(cid:3) Laterally: levator ani an d coccygeus. Blood supply Arterial (cid:142)(cid:3) Superior rectal from the inferior mesenteric artery (cid:142)(cid:3) Middle rectal from the anterior division of the internal iliac artery (cid :142)(cid:3) Inferior rectal from the internal pudendal artery. Venous drainage (cid:142)(c id:3) Superior rectal vein to the portal vein (cid:142)(cid:3) Middle and inferior rectal v ein to the internal iliac. These systems are in communication, forming a potential porto-sy stemic anastomosis. THE RECTUM1 75 Rectum Anal sphincter Anal valves Fig. 3.13 The rectum CHAPTER 3 Anatomy for surgeons 76 The anal canal The anal canal is the terminal part of the alimentary tract. It is 4cm long. Embryology (cid:142)(cid:3) Upper half: derives from endoderm. (cid:142)(cid:3) Lower half: derives from ectoderm. Epithelial lining (cid:142)(cid:3) Upper half: columnar epithelium. Adenocarcinomas usually arise from this area. (cid:142)(cid:3) Lower half: squamous epithelium. Squamous carcinomas usually arise from this area. The line where the lining changes is termed the dentate line. Blood supply Arterial (cid:142)(cid:3) Upper half: superior rectal artery (cid:142)(cid:3) Lower half: inferior rectal artery. Venous (cid:142)(cid:3) Upper half: tributary of the po rtal system (cid:142)(cid:3) Lower half: drains into the systemic venous system. Lymphatic drainage (cid:142)(cid:3) Upper half: to abdominal lymph nodes via the superior r ectal vessels (cid:142)(cid:3) Lower half: to inguinal lymph nodes. Nerve supply (cid:142)(cid:3) Upper half: autonomic nervous system (insensitive to pinprick sensation) (cid:142)(cid:3) Lower half: somatic innervation (sensitive to pinprick sensati on). Anal sphincters The anal canal is surrounded by: (cid:142)(cid:3) Internal sphincter: smoot h muscle (cid:142)(cid:3) External sphincter: striated muscle. The external sphincter surro unds the internal sphincter. An inter- sphincteric groove exists between the two sphincters . Practical hint In minor procedures such as injections of hemorrhoids, the needle should be inserted in the upper half of the anal canal that is insensitive to pain. This page intentionally left blank CHAPTER 3 Anatomy for surgeons 78 The liver This, the largest organ of the body, lies in the right upper quadrant predominant ly to the right of the midline and mostly under cover of the ribs. In health it is not norm ally palpable in the abdomen and extends internally to T8 and the xiphisternum in the midli ne and almost level with the nipples on each side. Lobes (cid:142)(cid:3) Right (cid:142)(cid:3) Caudate (cid:142)(cid:3) Quadrate (cid:142)(c id:3) Left. Surfaces (cid:142)(cid:3) Anterior (cid:142)(cid:3) Posterior (cid:142)(cid:3) Superior (ci d:142)(cid:3) Inferior. The inferior surface is related to the viscera, the others to the d iaphragm. Ligaments (cid:142)(cid:3) Falciform on the anterior and superior surfaces separating the t wo lobes. It is a fold of peritoneum attached to the peritoneum of the an- terior abdominal wa ll. (cid:142)(cid:3) Ligamentum teres (vestigial umbilical cord) runs from the umbilicus in the edge of the falciform ligament, to the inferior surface where it enters a deep cleft \200 \224the fissure for the ligamentum teres. (cid:142)(cid:3) Ligamentum venosum (vestigial ductus venosus) lies in a fissure on the posterior surface separating the right and left lobes. (cid:142)(cid:3) Coronary ligaments are layers of peritoneum reflected on the left side to the diaphragm and enclosing the so-called bare area. Where they join to the right and left bare areas are the right and left triangular ligaments. Porta hepatis There is a deep cleft on the inferior surface of the right lobe. The quad- ra te lobe lies in front, and caudate behind. It transmits the portal vein, the hepatic artery , and the hepatic ducts. The bile ducts lie anterior to the vein and to the right of the ar tery. Branches of the portal vein, hepatic artery, and bile duct tributaries then run toget her into the lobes of the liver. These are the portal triad. Inferior vena cava (cid:142)(cid:3) Lies in a deep groove on the posterior surface 2cm to t he right of midline. There are three main hepatic veins draining approximately equal propor tions of the liver. These drain into the vena cava near the diaphragmatic surface of the li ver. Accessory smaller hepatic veins are common. THE LIVER1 79 Fig. 3.14 The liver: anterior view. From Textbook of anatomy, (ed. A. W. Rogers), 1992. Rep roduced with permission from Churchill Livingstone Fig. 3.15 The liver: posterior view. From Textbook of anatomy, (ed. A. W. Rogers), 1992. Re produced with permission from Churchill Livingstone CHAPTER 3 Anatomy for surgeons 80 Segmental anatomy This is based upon ramifications of the portal triad structures (portal v ein, hepatic artery and biliary apparatus). These ramifications accompany each other throug hout the liver. The first major divisions of the portal struc- tures divide the liver into a right and left lobe. The division is through a plane that runs from the inferior vena cav a to the middle of the gall- bladder fossa. These two lobes are further subdivided in segme nts: (cid:142)(cid:3) Right lobe: anterior and posterior segments (no external features indicate this plane of division) (cid:142)(cid:3) Left lobe: medial and lateral segments (plane of division: falciform ligament and fissure of the round ligament) (cid:142)(cid:3) Each segment is divided into superior and inferior subsegments. In total t here are eight segments. Their identification permits relatively avascular dissection and m inimizes the risk of injury of adjacent structures (considerable experience is essential in hepatic resection) during the operations of segmentectomy and lobectomy. Lesser omentum The peritoneal coverings converge inferiorly to form a wide fold under the l eft lobe of the liver. It is attached to the first 2.5cm of the duo- denum, the lesser curv ature of the stomach, and the diaphragm to the left between the liver and esophagus. Its ri ght edge is free, being the anterior border of the opening into the lesser sac. The common bile duct, the hepatic artery and portal vein lie in its free edge. Subphrenic spaces These are common sites of intra-abdominal abscesses. The right and left s ubphrenic spaces are between the liver and diaphragm, being separated from each other by th e falciform ligament. (cid:142)(cid:3) Right subphrenic space (Rutherford Morrison \200\231 s pouch) is below the liver, anterior to the posterior abdominal wall and related to the ga ll bladder, duodenum and right kidney (cid:142)(cid:3) Left subphrenic space is the lesser omental sac. Blood vessels (cid:142)(cid:3) Hepatic artery and portal vein carry blood to the liver. (ci d:142)(cid:3) The hepatic veins drain the liver into the inferior vena cava. Nerves (cid:142)(cid:3) Branches of the vagus nerve (cid:142)(cid:3) Branches of the coelia c plexus. THE LIVER1 81 Fig. 3.16 The functional division of the liver into segments. a) anterior view as seen in t he patient; b) anterior view with the liver \200\230flattened \200\231 in the ex-vivo posi tion (note that segments VI and VII may now be seen \200\224in vivo they appear more later- ally and posteriorly); c) inferior view. From Applied Basic Science for Basic Surgical Tra ining, (ed. A. T. Raftery), 2000. Reproduced with permission from Churchill Livingstone CHAPTER 3 Anatomy for surgeons 82 The gall bladder and bile ducts The gall bladder This is a pear-shaped organ attached to th e under surface of the right lobe of the liver and projects slightly beyond its free margin . It lies in the right upper quadrant of the abdomen below the upper ends of the linea semi lunaris. It comprises of: (cid:142)(cid:3) A fundus (cid:142)(cid:3) A body (cid:142)(cid:3 ) A neck. Features The gall bladder is about 10cm long and its fundus is completely covered with peritoneum. The body and neck are covered on three sides only, being connected anteri orly to the liver by loose connective tissue from which it is easily separated. The neck ha s a dilatation called Hartmann \200\231s pouch which hangs downwards and may be attached to the duodenum by folds \200\224 congenital or inflammatory. The neck becomes the cystic duc t which drains into the common hepatic duct to form the common bile duct. Blood supply (cid :142)(cid:3) Arterial: the cystic artery that usually is a branch of the hepatic artery. The cystic artery is contained in a triangular area called Calot s triangle. Its boundaries are: the liver, the cystic duct, and the common hepatic duct. (cid:142)(cid:3) Venous: small veins that drain into the liver. Bile ducts The right and le ft hepatic ducts emerge from the liver through the porta hepatis and unite to form the comm on hepatic duct, which continues as the common bile duct after being joined by the cystic d uct. The common bile duct This duct, 9cm long, lies in the free edge of the lesser omentum (3cm) then passes behind the first part of the duodenum (3cm) and penetrates its second par t obliquely (3cm) behind the head of the pancreas where it lies in a deep groove in front o f the right renal vein. Its lower end is dilated to form the ampulla of Vater in common wit h the main pancreatic duct. It enters the medial wall of the second part of the duodenum. R elations of the common bile duct (cid:142)(cid:3) The hepatic ducts and the supraduodenal p art of the common bile duct lie in the free edge of the lesser omentum. The hepatic artery lies on its left side. (cid:142)(cid:3) The portal vein lies posteriorly. (cid:142)(cid:3) The right hepatic arter y passes behind the common bile duct before giving off its cystic branch. (cid:142)(cid:3) The lower one third of the common bile duct may actually lie in a tunnel in the pancreas. THE GALL BLADDER AND BILE DUCTS1 83 Practical hints (cid:142)(cid:3) Intermittent compression of the free edge of the lesser om entum can be performed for up to 15 minutes at a time to control hepatic bleed- ing (Pringl e \200\231s maneuver). (cid:142)(cid:3) NB Variations are common. Some are illustrated. Failure to recognize these can spell disaster for the surgeon. Gall bladder Cystic artery Hartmann \200\231s pouch Cystic duct Common hepatic duct Portal vein Lesser omentum Common bile duct Ampulla of Vater Variations of the cystic artery Fig. 3.17 The gallbladder and bile ducts CHAPTER 3 Anatomy for surgeons 84 The pancreas This elongated, lobulated gland lies on the posterior abdominal wall at the le vel of L1 in the transpyloric plane. It develops from dorsal and ventral buds of endoderm w hich initially lie diametrically opposite each other. Subsequent duodenal rotation and asym metric growth lead to fusion of the buds. Their ducts become the accessory and main pancre- atic ducts. Abnormal or incomplete rotation produces an annular pancreas, which may cause duodenal obstruction. Features It has a head in contact with the duodenum on three sides, a neck which is indente d posteriorly by the portal and superior mesenteric veins, and a tail which is contained wi thin the lieno-renal ligament. On cut section the gland is triangular in shape with well-de fined superior and inferior bor- ders and a blunt anterior border to which the transverse m esocolon is attached. Relations Head (cid:142)(cid:3) Posterior: inferior vena cava, right renal vein and artery, terminal por- tion of common bile duct. (cid:142)(cid:3) Anterior: first part of duodenum, transverse colon, gastro duodenal artery. Body (cid:142)(cid:3) Posterior: aorta, branches of coeliac artery on the upper border, sup e- rior mesenteric on the lower border, splenic vein, left renal vein and artery, left supr arenal, hilum of left kidney. (cid:142)(cid:3) Anterior: transverse mesocolon, stomach, lesser sac. Pancreatic ducts The main duct arises in the tail, traverses the body and neck, and then cu rves downwards to reach the head. It empties into the ampulla of the bile duct on the media l wall of the second part of the duodenum at the greater duodenal papilla. The accessory pa ncreatic duct opens into the duodenum 2cm above the main duct. Blood supply (cid:142)(cid:3) Arterial: from the coeliac and superior mesenteric arteries. The head and uncinate process are supplied by the superior pancreatico- duodenal artery from the gas troduodenal artery and the inferior pancreaticoduodenal from the superior mesenteric artery . The remainder of the gland is supplied by the splenic artery. (cid:142)(cid:3) Venous: drainage is by corresponding veins to the portal vein. THE PANCREAS1 85 Fig. 3.18 The pancreas: anterior view. From Textbook of anatomy, (ed. A. W. Rogers), 1992. Reproduced with permission from Churchill Livingstone CHAPTER 3 Anatomy for surgeons 86 The genitourinary system The kidneys The kidneys are retroperitoneal organs. The right kidn ey is lower than the left one because of the liver, which is above it. Each kidney is sur- rounded by perirenal fat, which, in turn, is covered by the renal fascia. Especially poster iorly to the kidney, the renal fascia is surrounded by a layer of fat known as perirenal fa scia or Gerota \200\231s fascia. Each kidney comprises of: (cid:142)(cid:3) A capsule (cid: 142)(cid:3) Two surfaces: anterior and posterior (cid:142)(cid:3) Two borders: medial and l ateral (cid:142)(cid:3) Two poles: upper and lower (cid:142)(cid:3) A hilum where, in anter o-posterior direction, the renal vein, artery, and pelvis enter and leave the kidney. Internal structure (cid:142)(cid:3) Medulla: this is composed of 6 \200\22310 pyramids. The apex of the pyramids is directed toward the hilum, while the base is facing the outer caps ule. The apex opens into a minor calyx. The medulla contains loops of Henle and collecting tubes. (cid:142)(cid:3) Cortex: this is situated between adjacent pyramids and separates the base of the pyramids from the renal capsule. It contains glomeruli and convoluted tubes. Blood supply The right and left renal arteries are branches from the aorta. Each renal arte ry divides into segmental arteries. Based on this division the kidney presents five segment s: (cid:142)(cid:3) Apical (cid:142)(cid:3) Anterosuperior (cid:142)(cid:3) Anteroinferior (cid:142)(cid:3) Inferior (cid:142)(cid:3) Posterior. The right and left renal veins drain straight into the inferior vena cava. The ureters The ureters are tubular structures extend ing from the renal pelvis to the posteroinferior wall of the bladder. Each ureter is 25 \200\22330cm long and its diameter varies between 2 \200\2238mm. They are retroperitoneal t hroughout their length. Relations (cid:142)(cid:3) Abdominal part In the proximity of the p elvis, each ureter crosses anteriorly to the psoas muscle. The upper part of the right uret er is covered anteriorly by the second part of the duodenum. Its inferior part is posterior to the right colic vessels, ileocolic vessels and the root of the mesentery. On the left, the left colic vessels run anteriorly to the upper part of ureter. Inferiorly, the ureter i s crossed anteriorly by the sigmoid vessels. In proximity of the pelvis each ureter is cros sed anteriorly by the gonadal vessels. THE GENITOURINARY SYSTEM1 87 (cid:142)(cid:3) Pelvic part Male: each ureter runs medially to the internal iliac artery. At the level of the ischial spine the ureter turns medially, running down with branches of the hypogastric nerves. Just before entering the bladder, the ureter is crossed anteriorly by the vas deferens. Female: each ureter is lateral to the ovarian vessels. It runs along t he lateral wall of the pelvis. It is in close relation with the uterine artery, ovary (the ureter is posterior to it), and broad ligament of the uterus. In proximity of the neck of t he uterus, the uterine artery crosses the ureter again, being posterior to it. Blood supply (cid:142)(cid:3) The ureters receive arterial blood supply from the renal arte ry, branches of the abdominal aorta, gonadal vessels, common iliac arter- ies, and inferior ves ical artery. (cid:142)(cid:3) The venous drainage follows the arterial pattern. Veins from the ureter drain into the renal vein and inferior vena cava. Practical hints During procedures such as hysterectomy, right and left hemicolectomy, anter ior resection, and abdomino-perineal resections the ureters need to be identified to preven t ureteric iatrogenic injuries. The bladder This is an extraperitoneal organ, which lies in the pelvis. The empty bladder i s below the pubis. When full, it rises in the abdominal cavity. The bladder comprises of: ( cid:142)(cid:3) The fundus: postero-superior. (cid:142)(cid:3) The apex: antero-superior. ( cid:142)(cid:3) The body: postero-inferior. Here the two ureteric orifices open. (cid:142)( cid:3) The neck: inferior. It contains the internal urethral meatus. The triangular area de scribed by the two ureteric orifices and the inter- nal urethral meatus is called the trigo ne. Relations (cid:142)(cid:3) Anteriorly: the space of Retzius separates the bladder from the pubic symphysis. (cid:142)(cid:3) Superiorly: peritoneum with coils of small bowel and sigmoid colon. In the female the uterus is in relation with the bladder. (cid:142)(cid:3) Posteriorly: in the male, the rectum and the seminal vesicles. In the female, the vagina and the cervix. (cid:142)(cid:3) Laterally: the peritoneum covers the bladder down to the level of the umbilical artery. Below this level the bladder is in relation with the lateral walls of the pelvis. Blood supply (cid:142)(cid:3) Superior and inferior vesical arteries, from the anterior bra nches of the internal iliac artery. (cid:142)(cid:3) Short vesical veins. These form a rich venous plexus that is tributary of the internal iliac veins. CHAPTER 3 Anatomy for surgeons 88 Lymphatic drainage (cid:142)(cid:3) To the external iliac lymph nodes from the anterior par t of the bladder. (cid:142)(cid:3) To the hypogastric lymph nodes from the posterior part of the bladder. Nerve supply (cid:142)(cid:3) Extrinsic nerves: from the inferior hypogastric plexuses. (ci d:142)(cid:3) Intrinsic nerves: from a perivesical plexus which receive both para- sympathetic fibers (S2 \200\223S4) and sympathetic fibers (T11 \200\223L2). Practical hint (cid:142)(cid:3) Because of the relation between sigmoid colon and bladder, diverticu- litis may lead to formation of a colo-vesical fistula. (cid:142)(cid:3) Since an empty bladder does not rise above the pubis, insertion of a supra pubic catheter must not be attempted unless the bladder is full. The prostate Most of the prostate surrounds the posterior and lateral aspects of the prosta tic urethra. A minimal amount of prostate lies anterior to the urethra. The prostate compri ses of: (cid:142)(cid:3) Lateral lobes: they are continuous anteriorly, but separated poste riorly by a midline sulcus) (cid:142)(cid:3) Median lobe: it lies posteriorly between ejaculatory ducts and the urethra (cid:142)(cid:3) Posterior lobe: atrophic (cid:142)(cid:3) Isthmus: anterior to urethra. It is composed of two main components: (cid:142)(cid:3) Glandular component (cid:142)(cid:3) Smooth muscle component. Relations (cid:142)(cid:3) Superiorly: neck of the bladder and sem inal vesicles. (cid:142)(cid:3) Inferiorly: urogenital diaphragm. (cid:142)(cid:3) Anterior ly: lower part of the pubic symphysis. (cid:142)(cid:3) Posteriorly: rectum (separated by t he fascia of Denonvilliers). (cid:142)(cid:3) Laterally: levator ani. Blood supply (cid:142 )(cid:3) The inferior vesical artery (branch of the internal iliac artery) is the main source of blood supply. (cid:142)(cid:3) Venous blood is drained through the prostatic venous plexus into the vesical and hypogastric veins. THE GENITOURINARY SYSTEM1 89 Inferior vena cava Right kidney Right renal vein Left kidney Left renal vein Right ureter Left ureter Aorta Bladder Fig. 3.19 The kidneys and ureters Apical segment Upper segment Cortex Renal artery Middle segment Medulla Renal vein Ureter Pyramid Lower segment Fig. 3.20 The segments and blood supply of the kidneys Bladder and prostate posterior view Urinary bladder Peritoneum Left ureter Right ureter Vas Deferens Seminal vescicles Prostate Urethra Fig. 3.21 The bladder and prostate: posterior view This page intentionally left blank Chapter 4 91 Surgical instruments, materials, and the acquisition of surgical skills G. O \200\231Dair, G. R. McLatchie, and David J. Leaper Introduction 92 Scalpel handles 94 Needle holders 94 Scissors \200\224suture and dissecting 96 Tissue dissecting forceps 98 Ti ssue holding forceps 98 Artery forceps 100 Hand-held retractors 101 Self-retaining retracto rs 103 Bowel clamps 107 Vascular instruments 109 Suckers 111 Endoscopic equipment 112 Lapar oscopic equipment 116 Suture materials 122 Knot tying 124 Surgical drains 135 Preparations for surgery 137 Abdominal incisions 138 Upper gastrointestinal endoscopy 142 Examination of the anus and rectum 144 CHAPTER 4 Surgical instruments, materials, and skills 92 Introduction There is considerable variation in the types of instruments used in differ- en t hospitals and the manufacturing companies who produce them. Instruments carry both generi c and eponymous names which can lead to confusion. It is important for the surgeon and thea ter staff to have a mutual understanding of the names of surgical instruments. The basic surgical trainee, in order to assist and perform surgical op- erations, needs to be familiar with several basic types of general surgical instruments. These fall under the following categories: (cid:142)(cid:3) Scalpel handles (cid:142)(cid:3) Needle holders (cid :142)(cid:3) Scissors \200\224suture and dissecting (cid:142)(cid:3) Tissue dissecting forc eps (cid:142)(cid:3) Tissue holding forceps (cid:142)(cid:3) Artery forceps (cid:142)(cid:3 ) Hand-held retractors (cid:142)(cid:3) Self-retaining retractors (cid:142)(cid:3) Bowel cl amps (cid:142)(cid:3) Vascular instruments (cid:142)(cid:3) Suckers (cid:142)(cid:3) Endosc opic equipment (cid:142)(cid:3) Laparoscopic equipment. This page intentionally left blank CHAPTER 4 Surgical instruments, materials, and skills 94 Scalpel handles Scalpel holders are numbered and accommodate a variety of sizes of scalpel blades. Care should be taken to mount and remove scalpel blades using an artery clip (Fig. 4.1). Needle holders Most needle holders are ratcheted and have a specially designed surface betw een the jaws to allow a firm grasp of the needle and prevent it twisting. They should be pl aced halfway along the needle to avoid dam- age to the needle point and the swage (which wo uld cause detachment from the suture). (Fig. 4.2) SCALPEL HANDLES1 95 Fig. 4.1 Scalpel holders no. 3, 4, and 5 Fig. 4.2 Mayo, Masson, and DeBlakey needle holders CHAPTER 4 Surgical instruments, materials, and skills 96 Scissors \200\224suture and dissecting Scissors are either straight or curved and used to c ut sutures or for dissection. Longer curved scissors are useful for dissection deep within body cavities. (Figs. 4.3 \200\2234.5) Fig. 4.3 Short and long McKindoe scissors SCISSORS \200\224SUTURE AND DISSECTING1 97 Fig. 4.4 Straight and curved Mayo scissors Fig. 4.5 30cm Metzenbaum/Nelson scissors CHAPTER 4 Surgical instruments, materials, and skills 98 Tissue dissecting forceps Dissecting forceps aid surgical dissection. Delicate structures s uch as bowel, arteries and veins etc. are handled with non-toothed forceps, while more robu st structures can be handled with toothed forceps, for example the skin or abdominal wall. The teeth can be used as a hook with avoidance of tissue damage. (Fig. 4.6) Tissue holding forceps Atraumatic tissue holding forceps, such as Duval and Babcock, can be used to manipulated bowel and visceral structures. Lane and Allis forceps cannot be used t his way as they are relatively traumatic and hence used to hold the skin and abdominal wall . Rampley sponge holders can also be used as tissue forceps such as retracting on the gallb ladder fundus during open cholecystectomy. (Fig. 4.7) TISSUE DISSECTING FORCEPS1 99 Fig. 4.6 Tissue dissecting forceps Fig. 4.7 From top: Rampley, Babcock, Littlewood, Duval, and Allis tissue holding forceps CHAPTER 4 Surgical instruments, materials, and skills 100 Artery forceps Artery forceps vary in size and are either straight or curved. They are used to clamp vascular structures prior to division and ligation. (Fig. 4.8) Fig. 4.8 From top: Mosquito, Criles, 7 inch Spencer Wells, Rochester-Penn, and Moynihan art ery forceps ARTERY FORCEPS1 101 Hand-held retractors Hand-held retractors are used by assistants during operative procedure s in order to provide the surgeon with a clear field of vision of the opera- tive field. (F igs. 4.9 \200\2234.11) Fig. 4.9 CHAPTER 4 Surgical instruments, materials, and skills 102 Fig. 4.10 Fig. 4.11 ARTERY FORCEPS1 103 Self-retaining retractors These allow assisting surgeons to be used for other tasks by retr acting open the surgical wound. (Figs. 4.12 \200\2234.17) Fig. 4.12 Travers self-retaining retractors CHAPTER 4 Surgical instruments, materials, and skills 104 Fig. 4.13 Jolles retractor (thyroid surgery) ARTERY FORCEPS1 105 Fig. 4.14 West retractor Fig. 4.15 Balfour set CHAPTER 4 Surgical instruments, materials, and skills 106 Fig. 4.16 Goligher set Fig. 4.17 Turner Warwick set ARTERY FORCEPS1 107 Bowel clamps Crushing bowel clamps are either curved or straight. Traumatic clamps occlude bowel that will be removed with the resection specimen. Non- crushing bowel clamps atraumat ically occlude bowel that is not resected to prevent spillage of bowel content prior to ana stomosis or stomal formation. (Figs. 4.18 \200\2234.21) Fig. 4.18 Hayes (top) Zachary-Cope (bottom) (closed) Fig. 4.19 Hayes (top) Zachary-Cope (bottom) (open) CHAPTER 4 Surgical instruments, materials, and skills 108 Fig. 4.20 Doyen bowel clamps (closed) Fig. 4.21 Doyen bowel clamps (open) ARTERY FORCEPS1 109 Vascular instruments Fig. 4.22 Satinsky (top) Fig. 4.23 O \200\231Shaughnessy (top) Lancy (bottom) CHAPTER 4 Surgical instruments, materials, and skills 110 Fig. 4.24 Ringed Bulldog (top) Debakey (bottom) ARTERY FORCEPS1 111 Suckers Fig. 4.25 Poole Sucker. Low pressure, internal/external sheath. CHAPTER 4 Surgical instruments, materials, and skills 112 Endoscopic equipment Gastroscopy set Components Light source Water bottle (air feed system) Mouth guard Biopsy forceps Gastroscope \200\224lens tip control air/suction buttons biopsy channel suction/air feed connectors. Light source Water bottle (air feed system) Mouth guard Tip control lens Air-feed connector Biopsy channel Air/suction Suction Biopsy forceps Fig. 4.26 Gastroscopy set ENDOSCOPIC EQUIPMENT1 113 Proctoscopy/sigmoidoscopy set Components Light source Light lead Bellows and eyepiece Biops y forceps Light attachment Proctoscopes (adult and pediatric) Sigmoidoscopes (rigid). Proctoscopes (adult) Light attachment Light source Pediatric Bellows Biopsy forceps Light lead Eyepiece (lens) Fig. 4.27 Proctoscopy/sigmoidoscopy set CHAPTER 4 Surgical instruments, materials, and skills 114 Flexible sigmoidoscopes Components Light source Light connection Suction valve Biopsy force ps Flexible sigmoidoscope \200\224tip control air/suction buttons biopsy channel. Light source Light connection Suction valve Tip control Flexible sigmoidoscope Suction Biopsy channel Air Biopsy forceps Fig. 4.28 Flexible sigmoidoscope ENDOSCOPIC EQUIPMENT1 115 Colonoscope Components Light source Light connection Colonoscope \200\224tip controls water/wash pipe suction valve light connection. Light source Light connection Tip controls Water wash Light connection Suction valve Fig. 4.29 Colonoscope CHAPTER 4 Surgical instruments, materials, and skills 116 Laparoscopic equipment Fig. 4.30 Laparoscope. Monitor (top), light source, Mavigraph (video printer), and VCR Fig. 4.31 Laparoscope. Light cable and camera Fig. 4.32 Camera LAPAROSCOPIC EQUIPMENT1 117 Fig. 4.33 Insulator Fig. 4.34 Endopath. Disposable surgical trochars Fig. 4.35 10mm trochar, Veress needle, Hasson trochar, and \200\230S \200\231 refractors CHAPTER 4 Surgical instruments, materials, and skills 118 Fig. 4.36 5mm instruments Fig. 4.37 5mm grasper Fig. 4.38 Laser fiber (top), laser scalpel, irrigator aspirator and Irrivac Fig. 4.39 Laparoscopic scissors. Designed as either curved, hooked, or straight, there is a variety available LAPAROSCOPIC EQUIPMENT1 119 Fig. 4.40 (a) 10mm claw grasper; (b) 10mm spoon forcep Fig. 4.41 Heater probe CHAPTER 4 Surgical instruments, materials, and skills 120 Anesthesia Video monitor Video monitor Video camera Laser Surgeon First assist Electrocautery Light source insuflator Camera driver Nurse Suction Ring basin stand Foot board Mayo stands ( \227 2) Fig. 4.42 Room set-up (appendicectomy) LAPAROSCOPIC EQUIPMENT1 121 Fig. 4.43 ENDOLOOP ligature with reducer (top), LIGACLIP endoscopic clip applier and clips Anesthesia Video monitor CO2 insulator Argon laser Surgeon 2nd circulator (laser safety officer) 1st circulator (R.N.) Instrument table Camera operator Monitor camera Light source VCR mavigraph Back table Mayo stand Fig. 4.44 Room set-up (cholecystectomy) CHAPTER 4 Surgical instruments, materials, and skills 122 Suture materials Suture materials in surgery can be categorized as absorbable and non- abso rbable and are composed of either natural or synthetic materials. The gauge or caliber are usually expressed using the US Pharmacopeia sizes (USP). USP Diameter (mm) 8/0 0.05 \200\2230.069 7/0 0.07 \200\2230.099 6/0 0.10 \200\2230.14 5/0 0.15 \200\2230.19 4/0 0.20 \200\2230.24 3/0 0.25 \200\2230.29 2/0 0.3 \200\2230.39 0 0.4 \200\2230.49 1 0.5 \200\2230.59 2 0.6 \200\2230.69 3 0.70 \200\2230.79