Nephrectomy

Key takeaways

Nephrectomy belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Nephrectomy to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Nephrectomy from memory before moving on to harder problems.

Reference excerpt

A nephrectomy is the surgical removal of a kidney, performed to treat a number of kidney diseases including kidney cancer. It is also done to remove a normal healthy kidney from a living or deceased donor, which is part of a kidney transplant procedure.

History The first recorded nephrectomy was performed in 1861 by Erastus B. Wolcott in Wisconsin. The patient had had a large tumor and the operation was initially successful, but the patient died fifteen days later. The first planned nephrectomy was performed by the German surgeon Gustav Simon on August 2, 1869, in Heidelberg. Simon practiced the operation beforehand in animal experiments. He proved that one healthy kidney can be sufficient for urine excretion in humans.

Indications There are various indications for this procedure, including renal cell carcinoma, a non-functioning kidney (which may cause high blood pressure) and a congenitally small kidney (in which the kidney is swelling, causing it to press on nerves, which can cause pain in unrelated areas such as the back). Nephrectomy for renal cell carcinoma is rapidly being modified to allow partial removal of the kidney. Nephrectomy is also performed for the purpose of living donor kidney transplantation. A nephroureterectomy is the removal of a kidney and the entire ureter and a small cuff of the bladder for urothelial cancer of the kidney or ureter.

Procedure

The surgery is performed with the patient under general anesthesia. A kidney can be removed through an open incision or by laparoscopic surgery. For the open procedure, the surgeon makes an incision in the side of the abdomen to reach the kidney. Depending on circumstances, the incision can also be made midline. The ureter and blood vessels are disconnected, and the kidney is then removed. The laparoscopic approach utilizes three or four small (5–10 mm) cuts in the abdominal and flank area. The kidney is completely detached inside the body and then placed in a bag. One of the incisions is then expanded to remove the kidney for cancer operations. If the kidney is being removed for other causes, it can be morcellated and removed through the small incisions. Recently, this procedure is performed through a single incision in the patient's navel. This advanced technique is called single port laparoscopy. A total nephrectomy is the removal of at least the entire kidney, whereas a 'radical nephrectomy' also includes at least some perinephric fat, possibly including Gerota's fascia, and usually also the ipsilateral adrenal gland. For some illnesses, there are alternatives today that do not require the extraction of a kidney. Such alternatives include renal embolization for those who are poor candidates for surgery, or partial nephrectomy if possible. Occasionally renal cell cancers can involve adjacent organs, including the inferior vena cava (IVC), the colon, the pancreas or the liver. If the cancer has not spread to distant sites, it may be safely and completely removed surgically via open or laparoscopic techniques.

Kidney donation In January 2009, a woman who had previously had a hysterectomy was able to donate a kidney and have it removed through her vagina. The operation took place at Johns Hopkins Medical Center. This is the first time a healthy kidney has been removed via this method, though it has been done in the past for nephrectomies carried out due to pathology. Removing organs through orifices prevents some of the pain of an incision and the need for a cosmetically unappealing larger scar. Any advance which leads to a decrease in pain and scarring has the potential to boost donor numbers. This operation has also taken place at the Cleveland Clinic, which first performed transvaginal Nephrectomy. Living donation has a mortality risk of 0.03% during the procedure and seems to result in similar health outcomes to controls.

After care Pain medication is often given to the patient after surgery for pain at the site of the incision. An IV with fluids is administered. Electrolyte balance and fluids are carefully monitored, because these are the functions of the kidneys. It is possible that the remaining kidney does not take over all functionality. A patient may have to stay in the hospital between 2 and 7 days depending on the procedure and complications. Patients who have had open surgery will have to stay in hospital longer than those who have had laparoscopic surgery. Over the long-term, a person with only one kidney ("solitary kidney") may be more prone to developing chronic kidney disease (CKD). A 2014 study suggested that the lifelong risk of CKD is several-fold higher in kidney donors, although the absolute risk is still very small. A 2017 article in the New England Journal of Medicine suggested that persons with only one kidney, including those who have donated a kidney for transplantation or those whose kidney was removed for cancer, should avoid a high protein diet and limit their protein intake to less than one gram per kilogram body weight per day in order to reduce the long-term risk of CKD.

Partial nephrectomy

Partial nephrectomy is the surgical removal of a kidney tumor along with a thin rim of normal kidney, with the two aims of curing the cancer and preserving as much normal kidney as possible.

History Czerny first described a partial nephrectomy in 1890. However, due to limited x-ray and imaging capabilities to find small kidney tumors and significant complications associated with early operations it was largely abandoned. More recently, with improved imaging, improved surgical techniques and increased kidney tumor detection, partial nephrectomy is performed more often.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Nephrectomy

Start with the simplest possible case. Write down what Nephrectomy claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Nephrectomy before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Nephrectomy ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Nephrectomy

In research: Nephrectomy appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Nephrectomy in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Nephrectomy is common in secondary-school and first-year university syllabi. It links to neighbouring topics Nephrology procedures, Pediatric surgical procedures, Surgical oncology, so understanding it makes those chapters shorter.
In everyday life: Look for Nephrectomy outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Nephrectomy in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Nephrectomy means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Nephrectomy out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Nephrectomy in simple terms?

A nephrectomy is the surgical removal of a kidney, performed to treat a number of kidney diseases including kidney cancer. It is also done to remove a normal healthy kidney from a living or deceased donor, which is part of a kidney transplant procedure.

Why does Nephrectomy matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Nephrectomy?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Nephrectomy.