Fabulous gift

This was given to me today by a friend. It's a plate from Gray's anatomy (the book, not the tv show) with the cardiac anatomy labeled in latin. I absolutely love it.

Inguinal hernia

On Friday I assisted a laparoscopic bilateral inguinal hernia repair. For those of you uncertain where the inguinal area is, feel your hip bones at the bottom of your stomach. Draw a line from each hipbone to where your pubic hair starts. That's roughly the location of your inguinal ligament.

The surgery provided the best view of that anatomy of the lower anterior abdominal wall I have seen to date. Better than anatomy lab without question. I can't find a phenomenal photo of it, but this one isn't bad. There is a normal weak point in the abdominal wall in that region, called Hesselbach's triangle (the HT in the picture). The vessel that borders it is called the inferior epigastric (not labeled) and a hernia medial (in HT) is called a direct inguinal hernia whereas a hernia lateral to the vessel is called indirect (through the internal inguinal ring, labeled IIR in the picture). Two important anatomic regions lie near Hesselbach's triangle, making the surgery technically quite challenging. My attending affectionally refers to these as the triangle of doom (inferior, where the femoral vessels run) and the triangle of pain (lateral, where the genitofemoral nerve runs). During the surgery he would constantly yell out which triangle we were near when our instruments got too close (which was often, it's a tiny space). "Watch out for DOOM!" "Beware PAIN!"

It was a quick, interesting case to observe; a good start to the morning. It was followed by (yet another) anterior abdominal wall reconstrution.

The End of Anatomy

We had our anatomy closing ceremony today. After seven months and 32 labs of dissection, we have completed the anatomy curriculum. The occasion was marked by a series of awards, given out by the legend himself, Dr. Burkel, for the best anatomy students. I received recognition for setting up the practice exams for every sequence (with my colleague Zach).

One of the body donors had written a letter to the students who would be dissecting him and it was read to the whole class. It was a poignant and appropriate moment, but it was nevertheless awkward. While I try to be respectful of the body I worked on (I never cut of random body parts for fun or put him in strange poses), I simply cannot think of him as a living, breathing man while I'm sawing off his cheekbone or cutting his genitals in half.

Anatomy was a rite of passage, but I'm not unhappy it's over. It's important and valuable material, but it's simply not my favorite subject. I will miss the anatomy faculty, they are truly great teachers and interesting people.

Histology is also over, but that seems less momentous. Onwards to histopath! Only two sequences left... infectious diseases and development (and some clinical weeks in between). Two more months, then I'm an M2!

Pediatric Cardiology #1: Healthy Heart

I recently began working in clinical research again; with the Congenital Heart outcomes group. The study I'm working on has a much wider ranger of diagnoses that my previous work so I'm brushing up on my pediatric cardiology (in all that spare time medical school leaves). I thought it might be an interesting topic to share here, so this post is a primer on normal functioning (I did the drawings).

Unfortunately, most of the diagrams you see in books are functionally correct (ex. above), but not anatomically helpful. If you open up someone's chest (from the front, ie anterior or ventral) you do not see two ventricles sitting side by side. Instead, you see something more like...

You can see immediately that rather than a right-left orientation, the heart is really more front-back (anterior-posterior). Also, the ventricles are not so much "on top" as they are to the right. Which brings me to another point, we name everything by the patient's orientation. Thus, the right ventricle is the patient's right side, not yours. The whole heart sits slightly to the left of midline in the chest and its apex (point) is roughly beneath the left nipple.
The way blood flows through the two interconnected circuits - systemic (body) and pulmonary (lungs) - is frequently disrupted in congenital heart disorders. Normally, blood returns from the body through the superior vena cava (SVC) and inferior vena cava (IVC) into the right atrium (RA). As the right ventricle relaxes (diastole) it fills with blood from the right atrium. This is accomplished through a pressure difference between the ventricle (low) and the atrium (high), which opens the tricuspid valve. When the ventricle is full, the pressure will be higher than the atrium, pushing the valve closed (creating unidirectional flow). The ventricle contracts (systole) and blood enters the pulmonary trunk (through the pulmonary valve). The pulmonary trunk divides into a right and left branch to the right and left lungs. Each of these eventually becomes a capillary bed, which drains into small veins, which drain in to the 4 pulmonary veins. The pulmonary veins drain into the left atrium. As the left ventricle relaxes it fills with blood from the left atrium (same process as right ventricle, except the valve is called the mitral valve). When the left ventricle contracts it sends blood into the aorta (through the aortic valve). From the aorta blood goes all over the body and returns to the heart via the SVC/IVC.

There are two structures unique to babies' hearts: the foramen ovale and the ductus arteriosus. The foramen is a hole in the wall (septum) between the two atria. It's open and birth and normally closes in the first few days of life. Failure to close is called a patent foramen ovale (PFO) and can ultimately lead to congestive heart failure. The ductus is a vessel connecting the pulmonary trunk to the aorta. In fetal life it's used to bypass the lungs and it too usually closes soon after birth. Both of these conduits allow for mixing of blue (deoxygenated) blood and red (oxygenated) blood (which is a normal person is bad).

Summary: SVC/IVC -> R atrium -> (tricuspid) R ventricle -> (pulmonary valve) Pulmonary system -> L atrium (mitral) -> L ventricle -> (aortic valve) Aorta -> systemic circulation -> SVC/IVC

Key Points:
1. Ventricular filling is accomplished (almost entirely) through pressure differentials
2. The valves closing properly is important for unidirectional flow
3. There are two conduits for shunting blood from the right heart to the left: the foramen ovale and the ductus arteriosis
4. The pressures in the right heart are normally much lower than those in the left

If there are any questions, let me know and I will attempt to clarify. I only gets more complex from here!

Pre-dissection reflection

I've finally put my finger on why dissection is making me feel a little hesitant and slightly uncomfortable. It's not cutting into a body per se; I was fine while watching surgeries. It's the fact that dissection is intentionally destructive. Surgery is about health and healing, about the best interest of the patient and their future functionality and quality of life. Dissection is about complete and total deconstruction with no consideration for the future. It feels like a violation because this is invasion with no intent to heal; it's taking apart a human lego set piece by piece knowing that not only can you not put it back together, you're not even going to try.

On the one hand I want to be respectful, this was a person and even in death they deserve to be treated well. On the other hand, I want complete detachment and dehumanization because otherwise, how do I (inexpertly) flay someone's father/brother and just go home and make dinner?

In some cases, the body donor willingly gave themselves, but the family did not. How do I look those family members in the eye, knowing that what I'm doing is against their wishes? I don't really want to meet the family (now); that will only make it harder to keep cutting. Do they really want to meet me? Do they really want to see who is doing this to their father/brother? Will I look undeserving to them? Not what they imagined a future doctor will look like?