Jewish World Review May 4, 2004 / 13 Iyar, 5764




The highs & lows of C-reactive protein; Laparoscopic vs. open hernia repair; more

By Robert A. Wascher, M.D., F.A.C.S.

http://www.NewsAndOpinion.com | Regular readers of this column are well aware that an elevated blood level of C-reactive protein (CRP), an early player in the body's inflammatory response to injury and stress, is associated with a high risk of heart disease and stroke. Indeed, recent research indicates that CRP is actually a more accurate marker of heart attack risk than the traditional blood cholesterol tests that physicians have been ordering for years. Presently, most authorities consider a high-sensitivity CRP (hsCRP) blood level less than 1 mg/L to be associated with a very low risk of cardiovascular events such as heart attack and stroke.

HsCRP levels between 1 and 3 mg/L appear to be correlated with a moderate risk of cardiovascular events, while hsCRP blood levels at or greater than 3 mg/L are associated with a high risk of such events. A new study out of Harvard University, just published in the journal Circulation, has now extended our understanding of the cardiovascular event risk associated with hsCRP levels below 1 mg/L and above 3 mg/L.

In this very important study, 27,939 clinically healthy women were followed within a large long-term cardiac health study. The incidences of heart attack, stroke, coronary artery stent placement or bypass, and death due to cardiovascular causes were monitored over the duration of this still ongoing study.

After statistically adjusting results to account for individual cardiovascular risk factor differences in this large patient group, the investigators found a significant and linear correlation between hsCRP levels and the incidence of cardiovascular events, even at hsCRP levels as low as 0.5 mg/L. A blood hsCRP level of 0.5 mg/L was associated with a 60% increase in the relative risk of cardiovascular events when compared to patients with hsCRP levels less than 0.5 mg/L. Among patients with hsCRP levels of 4.0 to 5.0 mg/L, the increase in relative risk was 90% higher than for hsCRP levels less than 0.5 mg/L. Patients with hsCRP levels at or above 20 mg/L had the highest risk of experiencing adverse cardiovascular events: a more than 300% increase in relative risk when compared to patients with hsCRP levels less than 0.5 mg/L. Among this group of nearly 28,000 apparently healthy adult women, 15% had hsCRP blood levels less than 0.5 mg/L, while 5% had levels higher than 10 mg/L.

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This study is important because it demonstrates a linear correlation between CRP blood levels and the risk of adverse cardiovascular events at virtually all measurable levels of this pro-inflammatory protein. This study also confirms that, essentially, there is no "minimum" target for CRP reduction that is completely protective against cardiovascular events. This is analogous to recent research showing that reduction of even normal blood cholesterol levels in otherwise high-risk patients, using statin drugs, is associated with a significant decrease in the incidence of adverse cardiovascular events.

Interestingly, the statin drugs not only reduce the "bad cholesterol" (LDL) levels in the blood, but also appear to have an anti-inflammatory effect too, resulting in a reduction of CRP levels. Anti-inflammatory drugs such as aspirin and Celebrex may also exert as least some of their heart-protective effects by reducing blood levels of pro-inflammatory C-reactive protein. I predict that, within a few years, the American Heart Association will revise, downward, the current recommended target levels for LDL and CRP, based upon growing evidence that driving the these substances in the blood down to the lowest achievable levels is associated with significant reductions in cardiovascular disease events.

LAPAROSCOPIC VS. OPEN HERNIA REPAIR
Over the past decade, patients with groin hernias have had several choices available to them in deciding how to have their hernias surgically repaired. Approximately 500,000 inguinal hernia repairs are performed every year in the US, making it the most common operation done outside of the abdominal cavity by general surgeons.

Basically, there are three options for the repair of these weakened areas in the groin: repair with sutures alone, repair with a panel of mesh sewn over the weakened site, and laparoscopic mesh hernia repair. In the first two cases, a 3 to 4 inch incision is made in the groin area, and the hernia is directly repaired through this incision.

When a laparoscopic hernia repair is performed, 3 or 4 small puncture-like incisions are made on the lower abdomen, and highly specialized laparoscopic instruments are used to internally open up the hernia site, followed by repair of this weakened area of the abdominal wall with mesh. All portions of the laparoscopic repair are performed through the 3 or 4 small incision. (Suture-only open groin hernia repairs have been abandoned by most surgeons due to the high recurrence rate and moderate postoperative discomfort associated with this approach). Proponents of the laparoscopic approach cite a modest but significant decrease in discomfort during the early postoperative period, and a 1 or 2 day decrease in the delay before resumption of normal daily activities.

Critics of the laparoscopic approach cite the increased expense of the equipment and disposable supplies necessary to perform a laparoscopic hernia repair, the extra time needed to do a laparoscopic repair in the OR when compared to "open" repairs, and they cite several studies comparing open mesh repairs with laparoscopic mesh repairs that have shown essentially no significant differences in postoperative discomfort or recovery times between the two procedures.

A new study in the New England Journal of Medicine randomly assigned healthy adult males to either open mesh or laparoscopic mesh hernia repairs at 14 different VA medical centers. All patients were then followed for 2 years to identify the incidence of postoperative complications and recurrent hernias in each group of patients. A total of 1,983 patients participated in this study, and complete 2-year follow-up was available for 1,696 (86%) of participating patients. Recurrent hernias were twice as common in the laparoscopic group (10.1%) when compared to the open surgery group (5%). Postoperative complications were also slightly higher in the laparoscopic group (39%) when compared to the open surgery group (33%), including infection, numbness and chronic pain.

However, as has been suggested by previous studies, the laparoscopic surgery group had less incisional pain immediately after their hernias were repaired, as well as 2 weeks later. When compared to the open surgery group, the laparoscopic surgery group returned to normal activities an average of only 1 day earlier, however. When the investigators further analyzed their results, they also found that hernias were more likely to recur following laparoscopic surgery if the patient had undergone surgery to repair a hernia for the first time (10% for laparoscopic repairs vs. 4% for open repairs).

However, patients undergoing repair of a recurrent groin hernia had essentially the same incidence of subsequent hernia recurrence irrespective of the type of surgical repair (10% to 14%, which was not statistically significant). Overall, the investigators concluded that open mesh repair of inguinal hernias is associated with fewer postoperative complications and a lower incidence of hernia recurrence when compared to laparoscopic mesh surgical repairs. Although I am primarily a cancer surgeon, I still perform a considerable number of hernia repairs. While I do not perform as many laparoscopic repairs as I did when this technique was first developed, and surgeons were eager to apply this new approach in their practices, I still occasionally use the laparoscopic approach.

My own indications for a laparoscopic repair include patients with recurrent groin hernias following a previous open mesh repair (it is a very destructive and morbid process to try and remove an old mesh implant that has scarred into surrounding structures), and patients with bilateral ("double") hernias (one can repair both sides simultaneously through the same 3 to 4 small incisions using the laparoscopic technique).

Occasionally, I will also primarily repair the groin hernias of patients who have a compelling need to immediately resume work, and those who have physically demanding jobs in particular. In my own experience of performing laparoscopic internal hernia repairs for more than a decade, most patients experience very mild discomfort, and return to full activity within 24 to 48 hours following laparoscopic surgery.

Patients undergoing open mesh hernia repair tend to have a bit more discomfort during the first week or two after surgery, and tend to return to work several days later than my patients who have undergone laparoscopic hernia repair.

However, overall, my observations in my own practice over the years, and in the practices of my colleagues, are generally consistent with the findings of this study. As I have already long ago altered my own practice to more selectively recommend laparoscopic hernia repair, this study will not change my own approach to inguinal hernia repairs.

However, I do believe that surgeons who emphasize laparoscopic hernia repair in their practices should compare their own patient outcomes with those in this study. If an individual surgeon's results are essentially equivalent irrespective of the technique used, then there should be no problem with emphasizing laparoscopic hernia repair. However, the findings of this study, and of previous similar studies, suggest that most surgeons who perform hernia repairs should consider being very selective regarding the indications for performing a laparoscopic groin hernia repair.

BRIEFLY...
Journal of the American Medical Association (JAMA): 185 patients were randomized to coronary artery bypass surgery (CABS) with the cardiopulmonary bypass machine ("on pump") or without the bypass machine ("off pump"). Previous evaluations of "off pump" CABS have shown fewer complications and shorter hospital stays when compared to the traditional "on pump" method of CABS. However, the long-term results of this newer approach to coronary artery revascularization have been unclear. In this study, there was no significant difference in coronary artery graft patency or heart function between the "off pump" and "on pump" patients 1 year after CABS. At the same time, the hospital costs associated with "off pump" CABS were, on the average, more than $2000 lower than for the "on pump" group.

JAMA: In the first formal report on the "estrogen-only" arm of the Women's Health Initiative (WHI) study, the study's directors explain why they prematurely terminated their research project in February 2004. All 10,739 participants in this part of the WHI study were notified of the study's interim findings, and advised to discontinue their estrogen hormone replacement therapy (HRT). This large scale prospective, randomized, double-blinded, placebo-controlled study, started in 1993, was prematurely stopped because the women who were randomized to receive estrogen pills experienced a 40% increase in the relative risk of stroke when compared to the women who received the placebo pills.

Over an average follow-up period of just under 7 years, 12 additional strokes per 10,000 person-years resulted from the use of estrogen-only HRT. At the same, there was no improvement in the incidence of coronary heart disease or heart attacks among the women taking the estrogen pills. Interestingly, there appeared to be a 30% reduction in the relative risk of breast cancer among the study volunteers who received the estrogen pills (remember that the combination estrogen/progesterone HRT arm of the WHI was prematurely shut down in the spring of 2002 after it was discovered that combination HRT significantly increased the risk of breast cancer, as well as stroke and heart disease).

While the adverse effects of HRT appear to be less egregious with the estrogen-only regimen when compared to the estrogen/progesterone regimen, the two arms of the WHI clearly show that, at a minimum, HRT does not reduce coronary heart disease (indeed, combination HRT appears to significantly increase the risk of heart disease), and that both regimens significantly increase the risk of stroke as well. The discordant effects of each regimen on the incidence of breast cancer will certainly be the focus of intense future study.

British Medical Journal: Here's a study that one might file under the category of "research that confirms what everyone already knows:" A targeted school-based education program to reduce the consumption of carbonated soft drinks on campus resulted in a significant reduction in obesity among those children who reduced their intake of these sugary drinks....

JWR contributor Dr. Robert Wascher is an oncologic surgeon, professor of surgery, oncology research scientist, and author. He lives in Honolulu with his wife and two daughters. Comment by clicking here.

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© 2004, Dr. Robert A. Wascher