Saturday, January 4, 2014
I had a brief encounter with Big Blue today. I was doing a fairly routine laparoscopic hiatal hernia repair when it appeared, staring me straight in the face. It wasn’t lurking around the corner or hiding behind another structure, it was right there, only millimeters away from the area in need of repair. Such are the pitfalls and dangers we intrepid surgeons face on a daily basis.
Big Blue is better known as the Inferior Vena Cava, the largest vein in the human body. This monster’s function is to receive deoxygenated blood from most of the veins below the diaphragm and return it to the heart for processing, which means unwanted carbon dioxide is exchanged in the lungs for vital oxygen which is then delivered to the body.
This Inferior Vena Cava is a structure that demands respect and should be given a wide berth, if possible. Many surgeons reserve this attitude for the pancreas, but this large, thin walled blood vessel can be most unforgiving.
For any readers unfamiliar with human anatomy the body has several different types of vessels which carry blood and bodily fluids. Arteries are flexible, often muscular conduits which carry oxygenated blood under high pressure from the heart to body organs. The arteries progressively decrease in size as they branch into smaller arterioles and then capillaries, tiny thin walled, porous vessels which only allow cells to pass in single file affording them the opportunity to deliver their wares (oxygen, nutrients and such) to the body’s organs, while picking up unwanted waste materials to be carried to the various outlets which will eliminate said waste. These capillaries then coalesce into veins which merge into larger and larger vessels, culminating in the vena cavas, of which there are two, superior which carries blood from the head and arms to the heart, and inferior which is the subject of this treatise. There is one other type of vessel, lymphatics, which carry fluid which has been dumped into the environment outside the usual circulatory system, eventually bringing it back into the network of arteries, veins and capillaries.
This is not meant to be a dialogue on circulation, however. Rather, it is a discourse on the Inferior Vena Cava.
Getting back to my case, there it was, Big Blue confronting me and my surgical skills. A lesser man would have been reduced to a tower of quivering Jello by the mere proximity of such a beast, but your humble correspondent is made of sterner stuff. It is true that one misstep, one single slip of the hand would lead to disaster, a hole in the suprahepatic inferior vena cava.
Such an injury is very difficult to control and repair. This very short segment of the Inferior Vena Cava is right at the base of the heart. Bleeding from this area is akin to having a hole in the bottom of the heart. This is true because an injury to the suprahepatic vena cava really is a hole in the bottom of the heart. Every time the heart contracts its blood would be squeezed out this hole and the patient would bleed to death in short order. Traumatic injuries of this type are almost always fatal.
I did have to care for a patient with such an injury many years ago. Lydia had been in automobile accident. She arrived in our ER awake, alert, with a pulse, but we could not get a blood pressure. A peritoneal tap returned gross blood and she was whisked away to the OR. She was able to talk to us on the way and she had a weakly palpable femoral pulse.
As soon as we opened her abdomen we encountered blood, but where was it coming from? We packed all around the abdomen and then started our exploration. When I retracted downward on the liver blood poured out, the hallmark of a retrohepatic or suprahepatic vena caval injury. The problem now was that our exploration had disrupted any tamponade (compression) that was limiting the bleeding from the injured vessel. Blood started to pour out with every contraction of her heart.
The treatment of such an injury requires placement of an atrio-caval shunt, a large tube which is passed through the right atrium of the heart into the vena cava and then secured so that the blood will flow through the tube and not the injured blood vessel, thus maintaining blood flow while allowing the surgical team to make repairs. Such a shunt can usually be placed in a few minutes. Lydia however did not have even a few minutes and she died of this lethal injury.
Excuse my digression, back to my encounter with Big Blue. The truth is that on every hiatal hernia repair I am fully cognizant of the proximity of the Inferior Vena Cava. Often I see it clearly, sometimes I just wave at its presumed location. In this particular case I took my usual care and placed each suture exactly where I wanted it and was able to let sleeping monsters lie.
My first real encounter with Big Blue was many years ago, as a fourth year surgical resident. I had been seeing a patient who had barely survived a complicated Gynecologic/Surgical operation. She was in the ICU and developed a pulmonary embolus, which is a blood clot from the legs or pelvis which breaks away and becomes lodged in the lungs, a life-threatening, sometimes fatal condition. She could not be placed on blood thinners because of the potential for bleeding which comes with these medications, therefore it was decided to place a “clip” on her Inferior Vena Cava. This clip allows blood to flow through the large vein, but prevents large, possibly fatal, clots from passing. This was before the use of intraluminal vena caval filters became the norm.
Normally, this procedure would be a Chief Resident case, but I managed to schedule it at a time when all the Chief residents would be tied up in a conference, thus affording me the opportunity to do this rarely performed surgical procedure. Up until that time I had never done a similar operation and had never really worked on or around Big Blue. But, he who hesitates is lost. I read up on the technique before hand and was filled with the confidence of youth. And, I pulled it off like a pro. With two of my attending assisting Big Blue was approached form the right side, the peritoneal structures were dissected off the retroperitoneum and there I was, staring at the Inferior Vena Cava.
I gently began to spread and cut and spread until it was completely free. I slid the clip into place and closed it and that was it, my first successful encounter with Blue. My Chief Resident, however, was really mad that I stole this case.
There is another case that demonstrates just how dangerous and unforgiving the Inferior Vena Cava can be. It was actually one of my partners who started the surgery, which was the repair of a ruptured Abdominal Aortic Aneurysm. This is a condition where the major artery in body has weakened and then burst, most often fatal with or without surgery.
I was called to see if I could lend a hand. I found him up to his elbows in blood, doing his best to stop the bleeding from the vena cava adjacent to the abdominal aorta. Multiple sutures had been placed and torn through and now this giant vein was a macerated mess. With the patient already in extremis all we could do was ligate, or tie off, the vena cava above its bifurcation and then go on and fix the aneurysm. Unfortunately, this patient didn’t survive. Two lethal conditions simultaneously are too much for almost any individual or surgeon.
My fondest memory of battling the Vena Cava comes from Victor. Fond? Maybe not, but certainly challenging and interesting. He was forty eight years old and came to see me because his abdomen was swelling. He was a mailman and he had noticed the prominence when his mailbag hit against his abdomen. He had never had any surgery or medical problems. He had only vague discomfort and no other symptoms. He was sent off for work up with an abdominal and pelvic CT Scan and basic blood tests.
The results of these tests revealed a large intrabdominal mass overlying his Inferior Vena Cava and right Renal Vein, while displacing the right colon and duodenum. He was mildly anemic, but otherwise his blood tests were normal. A needle biopsy was also done which revealed a spindle cell tumor. Sarcoma, a type of cnacer, was suspected and surgery was scheduled.
Preoperative preparation included an arteriogram which provided a road map of the vessels supplying the tumor, a bowel prep because resection of a portion of the colon would likely be necessary along with all the routine antibiotics, type and cross match and such.
The big day (for the patient) arrived and he was whisked away to room five where he was epiduralized, catheterized, intubated, painted and draped. I made my usual grand entrance, with the theme from Rocky playing in the background, as my assistant, the circulating nurse, surgical tech and anesthesiologist bowed, my freshly washed and sanitized hands held high (not really). I was gowned and gloved and the surgery commenced.
A xiphoid to pubis midline incision brought us into the abdomen where the expected large mass was residing, pushing the colon up. The tumor was adherent to the mesentery of the right colon, but a bit of dissection revealed that the duodenum easily separated from the mass. With the duodenum out of the way and the tumor exposed, the operation could really begin. This mass was sitting on top of Big Blue.
I switched gears and began attacking this mass from behind the right kidney. The renal artery was not involved, but the mass was stuck to the right kidney, right renal vein and the Inferior Vena Cava. Next I started to gingerly dissect along Big Blue, starting on top of the right Iliac vein which is the vein which joins with its partner on the left to form the Inferior Vena Cava. The tumor became adherent to Blue a few centimeters above this bifurcation.
Decision time was at hand. It was clear that a proper, curative resection would require removing a portion of Big Blue, as well as the right colon and right kidney. The big question loomed, however: Should the vena cava be ligated (closed completely by tying the divided ends) or reconstructed?
It wasn’t really a difficult decision as I barely paused before asking to see what grafts were available. I chose an appropriately sized “Platinum” graft and then really went to work. The terminal ileum was divided as was the transverse colon and the colonic mesentery (blood supply). Thus the colon was now free. The right kidney was dissected away from the surrounding tissue and the right renal artery ligated and divided. Finally the vena cava was dissected away from its resting place next to the aorta. Multiple lumbar veins were dissected free, clipped and divided. Finally I was left with only Big Blue. There was about seven centimeters of vena cava which would require removal. The big vein was clamped above its bifurcation and below the liver, divided and the cantaloupe sized tumor was removed en bloc with the right colon, right kidney and a portion of Big Blue.
Next it was time for reconstruction. Although I’m never thrilled about putting a prosthetic graft into a patient at the same time as a colon resection there was little choice in Victor’s case. His bowel was clean, however, and I made every attempt to limit the risk of contamination.
First, I rebuilt the vena cava. Some 5-0 Prolene suture, a bit of care and the first anastamosis was done. A few minutes later and the second was completed. Now the moment of truth: the clamps were removed and, voila, blood was flowing through the graft and there was no leak. I put his colon back together next, doing my best to shield the new graft from any potential contamination.
Victor didn’t turn a hair during his postoperative recovery. The tumor was found to be a liposarcoma, a type of cancer which probably originated in a single fat cell. After he had recovered from surgery and returned to work I didn’t give him much thought. As I tell many of my patients: “If you had surgery years ago and I remember you well, it means you either had a very unusual case or you had a significant complication. So be glad that I don’t recall doing your gallbladder surgery fifteen years ago.”
Victor did return however, eight years after his surgery. He appeared to be in robust health but he had developed a hernia in his midline wound. I repaired this without any fuss, managing to stay well away from “Big Blue” during this particular operation.