1. Borders of inguinal canal: 
-Superior: conjoint tendon (aponeuroses of internal oblique & transversus abdominis)
-Inferior: inguinal ligament
-Dorsal: tranversalis fascia
-Ventral: external oblique
2. Hasselbach's triangle: bordered by lateral rectus/semilunar line medially, inferior epigastric vv laterally, inguinal ligament inferiorly. Direct hernias occur into hasselbach's triangle, indirect hernias lateral to the epigastric vessels.
3. There is a space medial to the femoral vein, between the it and the lacunar ligament, at the most medial part of the space inferior to the inguinal ligament and superior to the ligament of cooper; this space is tight, and anything that gets stuck there is unlikely to be able to be manually reduced.
4. For hernia repairs, putting in a mesh has a lower recurrence rate (<1%) compared to Bassini repairs (sewing conjoint tendon to inguinal ligament)
5. Hernia tips:
-Hernias tend to occur on the R more than the L
-When you do abdominal surgery, make sure to repair the trnasversalis fascia well, because its the strength layer of the abdominal wall
6. Richter hernias-- the anterior/ventral wall of a segment of bowel is trapped -> venous edema -> necrosis. If you then reduce this hernia, it may perforate. If someone comes in with a relatively unimpressive looking hernia but with a lot of pain, after you reduce them, observe them for signs of rupture or peritonitis.
7. Spigelian hernias: at junction of arcuate and semilunar lines. The hernia only goes through the transversalis fascia, so it is unable to be appreciated on palpation, as it is still covered by the external and internal oblique muscles. Diagnose with CT, treat with laparoscopic repair.
8. Hepatic mass: before you biopsy, rule out hemangioma because they bleed a lot. Use radiolabeled RBCs, watch for filling from outside-in. Hepatic adenomas can also be bloody, and tend to respond to hormones-- i.e. OCPs or pregnancy. They are likely to rupture with pregnancy, so make sure to treat them before your patients get pregnant.
9. Hepatic cysts: simple hepatic cysts can be watched, complex cysts are suggestive of echinococcus; blood tests for echinococcus antigens to r/o. Drain carefully to prevent spillage of contents into the peritoneum, inject sclerosing agent (hypertonic saline).
10. Hepatic abscesses: Amebic abscesses can be treated with flagyl without drainage-- if you drain it, you might get a bacterial superinfection. Bacterial abscesses need to be drained, (if they are large and few) pts will usually have systemic signs of infection. IF there are many small abscesses, 4-6 weeks of IV abx. Bacterial abscesses can form from migration from GI tract into biliary system, or from bacteremia (from injection drug use or peritonitis working into the portal vein) seeding.