Friday 24 July 2015

What is a nephrectomy? |


Indications and Procedures

A kidney may be removed for several reasons, including congenital defects, trauma, cancer, inflammation, and transplantation. Congenital problems, or birth defects, associated with the
kidneys include abnormal development, nonfunctional cysts, blockage, tumors, and cysts that leave the kidneys functional but which cause difficulty in breathing because of their large size. A kidney may be removed if the organ or its main blood vessels have been damaged beyond repair by trauma, such as a gunshot wound. Cancer is one of the most common reasons for nephrectomy; kidney cancers include renal cell carcinomas, transitional cell carcinomas, and tumors in the capsules of the kidneys or in surrounding layers of tissue. Infections or abscesses in the kidney that are beyond medical treatment and that become life-threatening may also necessitate a nephrectomy. Finally, a kidney may be removed from a donor for transplantation.



Simple nephrectomies involve removal of the kidney only, whereas radical nephrectomies include removal of the kidney and surrounding glands. Depending on the underlying disease and the surgeon’s preference and experience, the kidney can be approached from the front, side, or back. The incisions used to reach the kidney are similar for simple, radical, and donor nephrectomies, but the steps that follow differ once the abdomen has been entered. For a nephroureterectomy, in which the kidney, the connecting ureter, and a part of the bladder are removed, the surgeon makes either one long, S-shaped incision starting in the flank and ending near the bladder, or two separate incisions.


In the frontal approach to nephrectomy, the patient lies on his or her back and the abdomen and peritoneal cavity are opened. The intestines near the kidney are pushed to the side, and the kidney is approached from the front. The advantage of this approach includes better evaluation of the liver and the structures surrounding the kidney, better control of the blood vessels, and easy removal of clots from veins if necessary. The disadvantages of this approach are the possibility of adhesions developing in the intestines and lung complications after the surgery. The frontal approach may also be laparoscopic, in which a number of small incisions are made in the abdomen; a camera is fed through one incision, and surgical tools through another; one of the incisions is then made larger for the removal of the kidney. A laparoscopic nephrectomy takes longer to perform but has a shorter recovery period with less postoperative discomfort.


In the side approach, the patient is placed on his or her side and the incision is made through the eleventh or twelfth ribs. The kidney is approached from behind. This type of incision involves cutting into muscle and results in significant postoperative pain. The main advantage is that the peritoneal cavity is not entered.


In the back approach, known as a dorsal lumbotomy, the patient is placed face-down and a muscle-splitting incision is used. The kidney is approached from behind. This method is usually used for a simple nephrectomy. Its primary advantages are less postoperative pain and avoidance of the peritoneal cavity. Its main disadvantage is a limited view of the surgery site.


In a simple nephrectomy, after the kidney has been exposed, Gerota’s fascia (the covering envelope of the kidney) is opened, and the fat around the kidney is dissected. The adjacent blood vessels and the connecting ureter are tied and cut, and the kidney is removed. In a radical nephrectomy, the adjacent adrenal gland and surrounding lymph glands are also removed in the one block. For a nephroureterectomy, the ureter is not cut close to the kidney but is removed all the way down to the bladder. A 2-centimeter cuff of bladder is cut off, the entire specimen is removed, and the hole in the bladder is closed.


The techniques used with
kidney transplantation differ for cadaveric (deceased) donor nephrectomy and living related donor (LRD) nephrectomy. For cadaveric donor nephrectomy, the abdominal aorta (the main artery bringing blood to the kidney) and the inferior vena cava (the main vein taking blood away from the kidney) are isolated above and below the kidneys and cannulated with pipes to irrigate both kidneys with cold preservation fluid. Both kidneys and ureters, along with their related blood vessels, are removed. For LRD nephrectomy, the kidney is dissected along with its blood vessels and ureter. Great care is taken to obtain the maximum length of ureter and blood vessels without causing damage to the donor.




Uses and Complications

The major complications of nephrectomy during surgery are bleeding, damage to surrounding structures, and problems related to anesthesia. Therefore, there is significant evaluation of the patient before surgery. A battery of tests may be performed, including blood testing, urinalysis, electrocardiography, and x-rays. A thorough medical examination is done to determine whether the patient can be placed under anesthesia safely. The patient’s blood is also typed and cross-matched in the event that a transfusion is required. Good surgical skills, the availability of blood for transfusion, and proper anesthesia techniques usually ensure that any complications that occur are not life-threatening. Nevertheless, the patient may also experience complications during the procedure that are not directly related to the surgery, such as a heart attack.


After a nephrectomy, the patient is at some risk for other problems. These complications may include bleeding, infection, intestinal obstruction, blood clots in the legs or lungs, or a heart attack.




Perspective and Prospects

Significant advances have been made in nephrectomy since the first such procedure was performed by Gustav Simmons in 1869. Thorough preoperative evaluation; improved anesthesia techniques; a greater understanding of anatomy, physiology, and pathology (including the nature of infections and microorganisms); and the discovery of antibiotics have all led to better surgical techniques. As a result, the death rate for nephrectomy operations is only 1 percent.




Bibliography


Brenner, Barry M., et al., ed. Brenner and Rector’s The Kidney. 9th ed. Philadelphia: Saunders/Elsevier, 2012.



Danovitch, Gabriel M., ed. Handbook of Kidney Transplantation. 5th ed. Philadelphia: Lippincott Williams & Wilkins, 2010.



Hinman, Frank, Jr. Atlas of Urologic Surgery. 2d ed. Philadelphia: W. B. Saunders, 1998.



"Kidney Removal." MedlinePlus, October 9, 2012.



Kohnle, Diana. "Nephrectomy." Health Library, May 23, 2013.



Marshall, Fray F., ed. Textbook of Operative Urology. Philadelphia: W. B. Saunders, 1996.



"Nephrectomy (Kidney Removal)." Mayo Clinic, May 23, 2012.



Novick, Andrew C., and Stevan B. Streem. “Surgery of the Kidney.” In Campbell-Walsh Urology, edited by Patrick Walsh et al. 9th ed. 4 vols. Philadelphia: Saunders/Elsevier, 2007.



Schrier, Robert W., ed. Diseases of the Kidney and Urinary Tract. 8th ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins, 2007.

No comments:

Post a Comment

How can a 0.5 molal solution be less concentrated than a 0.5 molar solution?

The answer lies in the units being used. "Molar" refers to molarity, a unit of measurement that describes how many moles of a solu...