eMRCS Abdomen and Perineum Flashcards
A 23 year old man complains of severe groin pain several weeks after a difficult inguinal hernia repair. Which nerve is most likely to have been involved?
Genitofemoral Ilioinguinal Femoral Iliohypogastric Pudendal
Ilioinguinal nerve
The ilioinguinal nerve may have been entrapped in the mesh causing a neuroma.
Arises from the 1st lumbar ventral ramus with the iliohypogastric nerve. Passes inferolaterally through psoas major and over the anterior surface of quadratus lumborum. Pierces internal oblique and passes deep to aponeurosis of external oblique. Enters inguinal canal and passes through superficial ring to reach the skin.
A 67 year old man is undergoing an angiogram for gastro intestinal bleeding. The radiologist advances the catheter into the coeliac axis. At what spinal level does this vessel typically arise from the aorta?
T10 L3 L4 T12 None of the above
T12
Coeliac axis lies at T12, takes an almost horizontal angle off the aorta. It has three major branches: left gastric, common hepatic, splenic arteries.
A 45 year old man is undergoing a low anterior resection for a carcinoma of the rectum. Which of the following fascial structures will need to be divided to mobilise the mesorectum from the sacrum and coccyx?
Denonvilliers fascia Colles fascia Sibsons fascia Waldeyers fascia None of the above
Waldeyers fascia
Separates the mesorectum from the sacrum and will need to be divided.
A 73 year old man is due to undergo a radical prostatectomy for carcinoma of the prostate gland. To which of these lymph nodes will the tumour drain primarily?
Para-aortic Internal iliac Superficial inguinal Mesorectal None of the above
Internal iliac nodes
The prostate lymphatic drainage is primarily to the internal iliac nodes and also the sacral nodes. Although internal iliac is the first site.
Following an oesophagogastrectomy the surgeons will anastomose the oesophageal remnant to the stomach, which of the following is not part of the layers that comprise the oesophageal wall?
Serosa Adventitia Muscularis propria Submucosa Mucosa
Serosa
The wall lacks a serosa which can make the wall hold sutures less securely.
A 35 year old man presents to the surgical clinic with a suspected direct inguinal hernia. These will pass through Hesselbach’s triangle. Which of the following forms the medial edge of this structure?
External oblique aponeurosis Inferior epigastric artery Rectus abdominis muscle Inferior epigastric vein Obturator nerve
Rectus abdominis
Direct inguinal hernias pass through Hesselbach’s triangle (although this is of minimal clinical significance). Its medial boundary is the rectus muscle.
A 72 year old man develops a hydrocele which is being surgically managed. As part of the procedure the surgeons divide the tunica vaginalis. From which of the following is this structure derived?
Peritoneum External oblique aponeurosis Internal oblique aponeurosis Transversalis fascia Rectus sheath
Peritoneum
The tunica vaginalis is derived from peritoneum, it secretes the fluid that fills the hydrocele cavity.
A 23 year old man is undergoing an inguinal hernia repair. The surgeons mobilise the spermatic cord and place it in a hernia ring. A small slender nerve is identified superior to the cord. Which nerve is it most likely to be?
Iliohypogastric nerve Pudendal nerves Femoral branch of genitofemoral nerve Ilioinguinal nerve Obturator nerve
Ilioinguinal nerve
The ilioinguinal nerve passes through the inguinal canal and is the nerve most commonly identified during hernia surgery.
The genitofemoral nerve splits into two branches, the genital branch passes through the inguinal canal within the cord structures. The femoral branch of the genitofemoral nerve enters the thigh posterior to the inguinal ligament, lateral to the femoral artery.
The iliohypogastric nerve pierces the external oblique aponeurosis above the superficial inguinal ring.
A 60 year old female is undergoing a Whipples procedure for adenocarcinoma of the pancreas. As the surgeons begin to mobilise the pancreatic head they identify a large vessel passing inferiorly over the anterior aspect of the uncinate process. What is it likely to be?
Coeliac axis SMA IMA Aorta Left gastric artery
SMA
Arises from the aorta and passes anterior to the lower part of the pancreas. Invasion of this structure is a relative contraindication to resectional surgery.
An 84 year old lady presents with a tender painful lump in the right groin and signs of small bowel obstruction. What is the most appropriate surgical incision to address this problem?
Lotheissen McEvedy Midline abdominal Paramedian Kochers
McEvedy
Traditionally used to approach incarcerated femoral hernias.
The disadvantage of the Lotheissen approach is that it weakens the inguinal canal and predisposes to inguinal hernia formation.
The other incisions would not usually address femoral hernias. Given the features of bowel obstruction, a low approach would be inappropriate.
At what level does the aorta bifurcate into the left and right common iliac arteries?
L1 L2 L3 L4 L5
L4
The aorta typically bifurcates at L4. This level is usually fairly constant and is often tested in the exam.
What structures are located on the transpyloric plane (L1)? (where lateral border of rectus muscle crosses the costal margin)
Pylorus of stomach Fundus of gallbladder Neck of pancreas DJ flexure 2nd part of duodenum Spleen Left and right colic flexure Root of transverse mesocolon SMA Portal vein Upper part of conus medullaris SMA
Anatomical planes and their levels?
Subcostal plane
Transpyloric plane
Intercristal plane
Intertubercular plane
Subcostal - Lowest margin of 10th costal cartilage
Transpyloric - L1
Intercristal - L4 (highest point of iliac crest)
Intertubercular - L5
Common level landmarks?
IMA
Bifurcation of aorta into common iliac arteries
Formation of IVC
Diaphragm apertures
IMA - L3
Bifurcation of aorta - L4
Formation of IVC - L5 (union of common iliac veins)
Diaphragm apertures - T8 IVC, T10 oesophagus, T12 aorta
A 63 year old man who smokes heavily presents with dyspepsia. He is tested and found to be positive for helicobacter pylori infection. One evening he has an episode of haematemesis and collapses. What is the most likely vessel to be responsible?
Portal vein Short gastric arteries SMA Gastroduodenal artery Splenic artery
Gastroduodenal artery
He is most likely to have a posteriorly sited duodenal ulcer. These can invade the gastroduodenal artery and present with major bleeding. Although gastric ulcers may invade vessels they do not tend to produce major bleeding of this nature.
Arises from common hepatic artery of coeliac trunk. Terminates by bifurcating into superior pancreaticoduodenal artery and right gastroepiploic artery. Supplies pylorus of stomach, proximal part of duodenum and indirectly into pancreatic head (via ant and post sup pancreaticoduodenal arteries)
The transversalis fascia contributes to which of the following?
Pectineal ligament Deep inguinal ring Cremaster muscle and fascia Inguinal ligament External spermatic fascia
Deep inguinal ring
The principal outpouching of the transversalis fascia is the internal spermatic fascia. The mouth of the outpouching is the deep inguinal ring.
The internal spermatic fascia invests:
Ductus deferens
Testicular vessels
During the course of a radical gastrectomy the surgeons detach the omentum and ligate the right gastro-epiploic artery. From which vessel does it originate?
Coeliac axis SMA IMA Common hepatic artery Gastroduodenal artery
Gastroduodenal artery
Arises at the superior part of the duodenum and descends behind it to terminate at its lower border. It terminates by dividing into the right gastro-epiploic artery and the superior pancreaticoduodenal artery.
The right gastro-epiploic artery passes to the left and between the layers of the greater omentum to anastomose with the left gastro-epiploic artery.
A 25 year old man has an inguinal hernia, which of the following structures must be divided (at open surgery) to gain access to the inguinal canal?
Transversalis fascia External oblique aponeurosis Conjoint tendon Rectus abdominis Inferior epigastric artery
External oblique aponeurosis
Question is asking what structure forms the anterior wall of the inguinal canal. The anterior wall is formed by the external oblique aponeurosis.
Once this is divided the canal is entered, the cord can be mobilised and a hernia repair performed.
The transversalis fascia and conjoint tendons form the posterior wall and would not routinely be divided to gain access to the inguinal canal itself.
Which of the vessels listed below is the most inferiorly sited single aortic branch?
Common iliac artery IMA SMA Gonadal artery Median sacral artery
Median sacral artery
Leaves the aorta a little above its bifurcation. It descends in the midline anterior to L4 and L5.
The inferior aspect of the vagina drains to which of the following lymph node groups?
Superficial inguinal nodes Internal iliac nodes Para-aortic nodes Obturator nodes Meso-rectal nodes
Superficial inguinal nodes
The lymph vessels from the superior aspect of the vagina join the internal and external iliac nodes, those from the inferior aspect of the vagina drain to the superficial inguinal nodes.
Which of the following is most important in providing support to the duodenojejunal flexure?
Mesentery of transverse colon Uncinate process of pancreas Gerotas fascia Ligament of Treves Ligament of Treitz
Ligament of Treitz
The suspensory muscle of the duodenum which is referred to as the ligament of Treitz is most important.
The ligament of Treves is located between the ileum and caecum.
A 25 year old man is being catheterised, prior to a surgical procedure. As the catheter enters the prostatic urethra which of the following changes will occur?
Resistance increase significantly Resistance increase slightly Resistance decrease It will lie horizontally It will deviate laterally
Resistance will decrease
The prostatic urethra is much wider than the membranous urethra and therefore resistance will decrease. The prostatic urethra is inclined superiorly.
A 73 year old lady with gallstones is about to undergo a laparoscopic cholecystectomy. The surgeon inserts a Verress needle and performs a successful drop test prior to establishing a pneumoperitoneum. A 5 minute delay ensues before a 10mm infraumbilical trocar is inserted. The surgeon performs a diagnostic laparoscopy which shows a thickened gallbladder but is otherwise normal. The anaesthetist complains that the patient has become hypotensive with a blood pressure of 80/40 mmHg. Of the options below, which is the most appropriate course of action?
Release of pneumoperitoneum Perform a laparotomy Administer IV adrenaline Administer IV amiodarone End the operation
Release of pneumoperitoneum
Excessive intra-abdominal pressure may cause decreased venous return and hypotension.
Since the preliminary laparoscopy did not show any major vascular catastrophe an emergency laparotomy would not be indicated. In most cases the release of pressure is often sufficient.
In cases of a vaso-vagal episode (which may be induced by peritoneal stretching) a dose of atropine may be required.
Which of the following structures lies posterior to the femoral nerve in the femoral triangle?
Adductor longus Pectineus Psoas major Iliacus None of the above
Iliacus
The iliacus lies posterior to the femoral nerve in the femoral triangle. The femoral sheath lies anterior to the iliacus and pectineus muscles.
Branches of the femoral nerve (L2-4)?
Medial cutaneous nerve of thigh
Intermediate cutaneous nerve of thigh
Saphenous nerve
What does the femoral nerve innervate?
Vastus lateralis/medius/intermedius
Quadriceps/rectus femoris
Sartorius
Pectineus
A 29 year old woman has had a Pfannenstiel incision. She has pain over the inguinal ligament which radiates to the lower abdomen. There is tenderness when the inguinal canal is compressed. Which of the following is most likely to have been affected?
Genitofemoral nerve Ilioinguinal nerve Lateral cutaneous nerve of thigh Iliohypogastric nerve Saphenous nerve
Ilioinguinal nerve
Surgeries and their associated nerve lesions:
Posterior triangle LN biopsy Lloyd Davies stirrups Thyroidectomy Anterior resection of rectum Axillary node clearance Inguinal hernia surgery Varicose vein surgery Posterior approach to hip Carotid endarterectomy
Posterior triangle LN biopsy - accessory nerve
Lloyd Davies stirrups - common peroneal nerve
Thyroidectomy - laryngeal nerve
Anterior resection of rectum - hypogastric autonomic nerves
Axillary node clearance - long thoracic, thoracodorsal, intercostobrachial nerve
Inguinal hernia surgery - ilioinguinal nerves
Varicose vein surgery - sural and saphenous nerves
Posterior approach to hip - sciatic nerve
Carotid endarterectomy - hypoglossal nerve
Which of the following overlies the outer muscular layer of the intrathoracic oesophagus?
Serosa Meissners plexus Auerbach's plexus Loose connective tissue None of the above
Loose connective tissue
The oesophagus has no serosal covering and hence holds sutures poorly. The Auerbach’s and Meissner’s nerve plexuses lie in between the longitudinal and circular muscle layers and submucosally. The sub mucosal location of the Meissner’s nerve plexus facilitates its sensory role.
The following are true of the femoral nerve, except:
Derived from L2-4 nerve roots Supplies sartorius Supplies quadriceps femoris Gives cutaneous innervations via saphenous nerve Supplies adductor longus
It supplies adductor longus
Adductor longus is supplied by the obturator nerve.
Which of the following structures is not directly related to the right adrenal gland?
Diaphragm posteriorly Kidney inferiorly Right renal vein Inferior vena cava Hepato-renal pouch
Right renal vein
The right renal vein is very short and lies more inferiorly.
An 18 year old boy is undergoing an appendicectomy for appendicitis. At which of the following locations is the appendix most likely to be found?
Pre-ileal Pelvic Retrocaecal Post-ileal None of the above
Retrocaecal
Most appendixes lie in the retrocaecal position. If a retrocaecal appendix is difficult to remove then mobilisation of the right colon significantly improves access.
