Helln

作者：Fran Lowry  
出處：WebMD醫學新聞

　　March 9, 2010 — 根據一項於3月10日發表於美國醫學會期刊（JAMA）的新研究結果，活體捐腎是安全的，且長期下來不會顯著增加死亡率。
　　
　　來自馬里蘭巴爾的摩約翰霍普金斯大學的Dorry L. Segev醫師與其同事們表示，每年超過6,000位健康美國國民因為活體捐贈目的接受腎臟切除。然而，因為縱向預後研究僅在單一中心進行，且普遍應用性有限，因此其安全性仍然存疑。
　　
　　這項研究的目的在於比較捐贈者與非捐贈者的長期死亡預後，同時研究全國活體捐贈者選擇與預後趨勢，以及估計不同活體捐贈者短期手術風險。
　　
　　研究者們檢驗1994年4月1日到2009年3月31日之間，於美國的80,347活體腎臟捐贈者的預後，這些捐贈者是來自法定國家註冊資料庫。包括9,364位相符個體資料取自於第三次全國健康與營養檢驗普查受試者；非捐贈者的資料儘量與捐贈者族群相符，以及儘可能選擇無活體捐贈禁忌症的受試者。
　　
　　後續追蹤時間中位數為6.3年（四分位數範圍為3.2-9.8年）。
　　
　　在試驗階段，腎臟捐贈後90天內有25件死亡事件。
　　
　　活體腎臟切除的頭90天，死亡風險為每10,000位捐贈者3.1件（95%信賴區間[CI]為2.0-4.6）。相對的，相對應族群的死亡風險為每10,000位0.4件（95% CI為0.1-1.1；P<0.001）。
　　
　　研究者們表示，即使有執業差異與病患選擇，手術死亡率在試驗期間的15年之間並沒有改變。
　　
　　這項研究也發現，男性的手術死亡率高於女性（每10,000捐贈者為5.1件相較於1.7件；風險比值[RR]為0.30；95% CI為1.3-6.9；P=0.007），黑人比白人與西班牙裔人種高（分別為每10,000位捐贈者有7.6位相較於2.6位與2.0位；相對風險[RR]為3.0；95% CI為1.3-6.9；P=0.01），且罹患高血壓的捐贈者相較於無高血壓者的風險同樣較高（每10,000位捐贈者有36.7位相較於1.3位；RR為27.4；95% CI為5.0-149.5；P<0.001）。
　　
　　然而，活體捐贈者的死亡長期風險比年齡相符、併存疾病相符非捐贈者高。
　　
　　研究者們評論，活體腎臟捐贈對接受者的好處是廣為人知的。移植領域有責任證實這些被拯救的生命不是用捐贈者風險增加換來的。
　　
　　不過，這項研究仍然有許多限制（只有在研究後段才有有關於教育程度、身體質量指數、高血壓、吸菸的資訊）、後續追蹤時間長度、以及源自於過度對應族群造成的統計人造偽跡。
　　
　　研究者們的結論是，不論怎樣的生理變化可能發生在一位捐贈腎臟的健康成人身上，我們發現捐贈者與健康對應病患的長期存活是相當的，這代表這些生理變化並不會造成過早死亡。
　　
　　雖然需要更多研究來了解這些變化，目前對活體腎臟捐贈的執業方法，在身故器官捐贈短缺下，應該繼續被認為是一個合理且安全的選項。
　　
　　作者們表示已於沒有相關資金上的往來。
　　  


Donating a Kidney Does Not Shorten Life

By Fran Lowry
Medscape Medical News

March 9, 2010 — Live kidney donation is safe and free from significant long-term excess mortality, according to new research published in the March 10 issue of the Journal of the American Medical Association.

"More than 6000 healthy US individuals every year undergo nephrectomy for the purposes of live donation," write Dorry L. Segev, MD, PhD, from the Johns Hopkins School of Medicine, Baltimore, Maryland, and colleagues. "However, safety remains in question because longitudinal outcome studies have occurred at single centers with limited generalizability."

The goal of this study was to compare long-term death rates between donors and nondonors, to study national trends in live donor selection and outcome, and to estimate short-term operative risk in various strata of live donors.

The investigators examined the outcomes of 80,347 live kidney donors in the United States between April 1, 1994, and March 31, 2009, who were drawn from a mandated national registry. A matched cohort of 9364 individuals was drawn from participants in the third National Health and Nutrition Examination Survey. The nondoners were as similar to the donor cohort as possible and were as free as possible from contraindications to live donation.

The median follow-up was 6.3 years (interquartile range, 3.2 - 9.8 years).

During the study period there were 25 deaths within 90 days of live kidney donation.

The risk for death in the first 90 days after live donor nephrectomy was 3.1 per 10,000 donors (95% confidence interval [CI], 2.0 - 4.6). In comparison, the risk for death in the matched cohort was 0.4 per 10,000 persons (95% CI, 0.1 - 1.1; P < .001).

Surgical mortality did not change during the 15 years of the study period, despite differences in practice and patient selection, the researchers note.

The study also found that surgical mortality was higher in men than women (5.1 vs 1.7 per 10,000 donors; risk ratio [RR], 3.0; 95% CI, 1.3 - 6.9; P = .007), in black vs white and Hispanic donors (7.6 vs 2.6 and 2.0 per 10,000 donors, respectively; RR, 3.1; 95% CI, 1.3 - 7.1; P = .01) and in donors with hypertension vs those without hypertension (36.7 vs 1.3 per 10,000 donors; RR, 27.4; 95% CI, 5.0 - 149.5; P < .001).

However, the long-term risk for death was no higher for live donors than for age- and comorbidity-matched nondonors.

The benefits of live kidney donation for the recipient have been well documented. It is incumbent on the transplant community to show that these lives are not saved at the cost of placing the donors at risk, the researchers comment.

The limitations of the study are availability of data (information about education, body mass index, hypertension, and smoking was only available in later periods), duration of follow-up, and statistical artifacts resulting from an overmatched cohort, the researchers note.

"Regardless of what physiologic changes might occur in a healthy adult after kidney donation, our findings of similar long term survival between donors and healthy comparison patients suggests that these physiologic changes do not result in premature death," the investigators conclude.

Although more studies are needed to understand these changes, "the current practice of live kidney donation should continue to be considered a reasonable and safe modality for addressing the profound shortage in deceased donor organs."

The authors have disclosed no relevant financial relationships.

JAMA. 2010;303:959-966.