Bessler Marc, Daud Amna, DiGiorgi Mary F, Schrope Beth A, Inabnet William B, Davis Daniel G
Center for Obesity Surgery, New York Presbyterian Hospital, Columbia University Medical Center, 161 Fort Washington Avenue, New York, NY 10032, USA.
Surg Obes Relat Dis. 2008 Jul-Aug;4(4):486-91. doi: 10.1016/j.soard.2008.05.010. Epub 2008 Jun 30.
The results of surgical procedures for weight loss are often described in terms of the percentage of excess weight lost. Expressing outcomes using the mean and standard deviation might not adequately describe the clinical experience. This could in part be because the use of the mean +/- standard deviation assumes a normal or random distribution of outcomes. It has been our perception that the weight loss results after gastric bypass are relatively normally and tightly distributed around the mean, making it relatively predictable. However, we have found that the results after adjustable gastric banding are more highly variable. In fact, there appears to be 2 groups of patients after this restrictive operation. One group, that is able to work well and does not struggle much against the restriction, accepts the limits that it imposes, and another group, that does not easily learn to deal with the restriction and hence mal-adapts.
To evaluate the validity of our clinical perception, we undertook an analysis of the distribution of weight loss by the percentiles of excess weight lost. All patients with follow-up of > or =1 years after gastric bypass or adjustable banding were evaluated for this analysis. The demographics and percentage of excess weight loss were evaluated. The distribution of the percentage of excess weight loss in 10% increments was evaluated.
Both groups were similar with respect to the mean patient age. However, the patients in the gastric bypass group had had a significantly greater mean preoperative body mass index and were more likely to be women. As expected, the weight loss of the gastric bypass patients fell in a normal single-peak distribution for < or =5 years of follow-up. The data from the adjustable gastric band patients at 1 year demonstrated a normal single-peak distribution, with a longer rightward tail. At 2 and 3 years postoperatively, the data from the band patients had a 2-peaked curve.
The initial weight loss results after gastric banding are less predictable than those after gastric bypass. A similar analysis of long-term outcomes might be enlightening and assist in making clinical decisions.
减肥手术的结果通常用超重减轻的百分比来描述。使用均值和标准差来表达结果可能无法充分描述临床经验。部分原因可能是使用均值±标准差假定结果呈正态或随机分布。我们的看法是，胃旁路术后的体重减轻结果相对呈正态且紧密围绕均值分布，使其相对可预测。然而，我们发现可调节胃束带术后的结果变化更大。事实上，在这种限制性手术后似乎有两组患者。一组能够很好地适应，不会因限制而过度挣扎，接受其所带来的限制；另一组则不容易学会应对这种限制，因此适应不良。
为评估我们临床看法的有效性，我们对按超重减轻百分比的体重减轻分布进行了分析。对所有胃旁路或可调节束带术后随访≥1年的患者进行此分析。评估人口统计学特征和超重减轻百分比。评估按10%增量的超重减轻百分比分布。
两组患者的平均年龄相似。然而，胃旁路组患者术前的平均体重指数显著更高，且更可能为女性。正如预期的那样，胃旁路患者的体重减轻在随访≤5年时呈正常单峰分布。可调节胃束带患者1年时的数据呈正常单峰分布，右侧尾部较长。术后2年和3年时，束带患者的数据呈双峰曲线。
胃束带术后的初始体重减轻结果比胃旁路术后的结果更难预测。对长期结果进行类似分析可能会有启发，并有助于做出临床决策。
