Sunday, February 10, 2008
Cold, snowy day in Cleveland area. Great time to get caught up on some reading. I've been churning through some journals; here's some highlights.
From Journal of the American College of Surgeons:
1. The neverending debate of hypertonic saline vs LR/normal saline in trauma fluid resuscitation will be revisited with a multicenter, randomized controlled trial comparing 28 day survival for the hypotension cohort and 6-month neurologic outcomes in the traumatic brain injury cohort. Patients will be randomized to either an initial 250cc bolus of 7.5% hypertonic saline, 7.5% saline with dextran, or .9% normal saline. After this initial fluid infusion, resuscitation is to proceed via usual institutional protocol.
Problems: Patients can receive up to 2 liters of IV fluid prior to enrollment in the study. Seems to me that presence or absence of pre-enrollment resuscitation is a potential confounding factor. Also, once the 250 cc blous is given, the patient gets any additional fluid support deemed appropriate. This means that someone may get his 250 cc of hypertonic saline, only to be followed by 6 or 7 liters of regular crystalloid, or even blood. How do you know if "differences" are more a reflection of the particular treatment arm or of the adequacy of overall resuscitation?
2. A good article on the importance of adequate lymphadenectomy in colon resections for colorectal cancer of the elederly (78 years old). This was a retrospective review of the National Cancer Data Base from 1998-2004. Standard of care is to remove at least 12 lymph nodes in segmental resections for colon cancer. Less than 12 can lead to understaging and compromised survival. The study suggests that patients older than 78 are more likely to have inadequate lymphatic sampling. I can see how this might have arisen; sometimes when doing major abdominal surgery on a frail, elderly patient, surgeons will want to just "get the thing out" as quickly as possible. Short cuts are taken. Maybe the mesentery isn't taken as high as it should. Maybe you skip the total mesenteric excision of rectal cancer. The idea is to remove the tumor as expeditiously as possible, trying to avoid the dangers of "high ligation" of vascular pedicles. Certainly in any oncologic operation, proper technique is paramount. A relatively healthy elderly patient with few co-morbidities deserves a proper operation, just as someone in their forties. But sometimes you get called for a bleeding cancer on a 90 year old guy with COPD/CAD, multiple abdominal operations, and the family doesn't want him to die of exsanguination.... it's a judgment call and as we take care of more patients in their ninth and tenth decades, you have to be careful insisting on "standards of care" in all situations.
3. "Significance of Sentinel Lymph Node micrometastases in breast cancer". Great learning article. This was a single institution retrospective review of over 2000 patients with sentinel lypmph nodes showing micrometastatic or no micrometastatic disease.
First, some terminology:
N0(i-): node negative with both H&E and immunohistochemistry (IHC) staining
N0(i+): node negative with H&E, but microscopically positive (up to .2mm) on IHC
N1(mi): node positive with H&E (size between .2 and 2mm)
Surgeons will usually perform completion axillary dissections with H&E positive sentinel nodes. The controversy recently has been what to do about sentinel nodes microscopically positive in IHC staining. Theoretically, omission of axillary dissection in these patients can lead to understaging of disease.
In this study, additional positive, non sentinel, lymph nodes were identified in 15.5% of patients with N1mi sentinel pathology, and 9.3% of patients with N0(i+) sentinel pathology. Interestingly, although survival was no different in patients with N0(i-) vs N0(i+) sentinel nodes, decreased survival was seen in N0(i+) patients when completion axillary dissection was omitted. Although not a randomized controlled trial, this article seems to suggest that even micrometastatic disease can portend poorer outcomes if completion axillary dissection is not done. Until things are clarified, I'll continue to do the dissection in micrometastatic disease....
4. A good study from Sloan-Kettering on the utility of MRI in the always difficult to manage setting of Paget's Disease of the breast.
Well, I was going to go through Annals and Archives of Surgery but.... this actually takes a long time and the Cavs are on soon and it's Sunday night and we're in full-fledged blizzard mode and I think it might be time for a cocktail...hopefully I'll get to them later this week.