SIMPLE AND RADICAL NEPHRECTOMY
Simple nephrectomy refers to the surgical removal of the kidney without the renal fascia or ipsilateral adrenal gland. This technique may be employed to treat non-neoplastic, irreversible kidney disease that poses an ongoing threat to the patient’s health. Possible indications include chronic pyelonephritis, chronic renal obstruction, extensive untreated nephrolithiasis, trauma, and ischemic nephropathy secondary to renal artery stenosis.
Radical nephrectomy, meanwhile, refers to the surgical removal of the kidney along with the perinephric fat, renal fascia, ipsilateral suprarenal gland, and ipsilateral retroperitoneal lymph nodes. Radical nephrectomy is the treatment of choice for patients with renal malignancies.
Both simple and radical nephrectomy may be performed using either an open or laparoscopic technique. In many cases, the surgeon will approach a simple nephrectomy with the same surgical strategy as a radical nephrectomy. Simple nephrectomies, however, may be technically more difﬁcult because of the tissue ﬁbrosis that commonly occurs secondary to chronic inﬂammation.
An open nephrectomy may be performed from a trans-peritoneal or retroperitoneal approach. Transperitoneal Approach. The anterior subcostal and chevron incisions are the standard incisions for the transperitoneal approach. For both, the patient is placed in supine position, and an incision is made approximately two ﬁngerbreadths below the costal margin. The incision extends from the anterior axillary line either to the xiphoid process (anterior subcostal incision) or to the opposite anterior axillary line (chevron incision). The dissection is carried down through the ﬂank musculature (latissimus dorsi, external oblique, internal oblique, transversus abdominis), anterior rectus fascia, and rectus abdominis muscles. The round ligament of the liver (ligamentum teres) is clamped and ligated. The colon is mobilized medially, and then the plane between the colonic mesentery and renal fascia is developed. The renal hilum is approached anteriorly, and the vessels are ligated using a combination of silk suture and surgical clips. The ureter is identiﬁed and ligated. The upper pole of the kidney is separated from the adrenal gland if desired.
A midline transperitoneal incision may be used for patients undergoing exploratory laparotomy for trauma, during which an indication for nephrectomy may be discovered. It is not a common incision in planned surgeries on the kidney, however, because the surgeon is often forced to operate caudal to the kidney. Such an approach can make it difﬁcult to achieve control of the hilar vessels, especially in obese patients.
A thoracoabdominal incision is used when radical nephrectomy is required in a patient with a large, right- sided upper pole tumor. The main advantage to this approach is the excellent exposure of the suprarenal area because inadequate retraction of the liver from another approach could impede vascular control and complicate removal of a large mass. The incision begins in the eighth or ninth right intercostal space near the angle of the rib and is carried medially to the midpoint of the left rectus muscle. The dissection is carried down to the pleura and diaphragm, which are circumferentially incised to expose the liver. The liver is then fully mobilized and retracted cephalad. Next, the duodenum is mobilized medially to expose the kidney and hilum. After the kidney is removed, the diaphragm must be sutured, a chest tube placed, and the pleura repaired. This approach is associated with a considerable risk of injury to the lung, and there is also signiﬁcant postoperative morbidity associated with the use of a chest tube. Therefore, this approach should be reserved only for large, right-sided upper pole tumors that cannot be safely removed with an anterior subcostal or chevron incision.
The major advantages to transperitoneal open access include the excellent exposure to the renal hilum and a large surgical ﬁeld, whereas the disadvantages include the risk of adjacent organ injury and of prolonged ileus.
Retroperitoneal Approach. The ﬂank incision is the standard incision for the retroperitoneal approach. The patient is placed in the lateral position after induction of anesthesia, with the table ﬂexed at the level of the twelfth rib to maximize the space between the costal margin and the iliac crest. An incision is made directly over the eleventh or twelfth rib starting posteriorly at the lateral edge of the erector spinae muscles. The rib chosen for dissection and possible removal is the one nearest the hilum, which can be determined most accurately on cross-sectional imaging. (The original method for making this determination was to draw a horizontal line on an intravenous pyelogram from the hilum to the most lateral rib the line intersects.) Dissection is carried through the latissimus dorsi, external oblique, and internal oblique musculature to the rib, which may be either retracted or resected. The transversus abdominis muscle and tendon of origin, as well as the thoracolumbar and transversalis fascia, are then incised to expose the paranephric fat. The peritoneum is identiﬁed and swept medially with manual dissection to separate it from the paranephric fat, which is then dissected to expose the renal fascia. In the case of a simple nephrectomy, the renal fascia is entered along its lateral surface. The kidney is pulled laterally to reveal the renal vessels and ureter, which are ligated. The kidney is then removed.
A dorsal lumbotomy incision can be used when retroperitoneal access to the kidney is desired in patients who have ﬁbrosis associated with prior abdominal or ﬂank incisions. The incision is started over the erector spinae muscles at the level of the twelfth rib, then continued downward and laterally toward the iliac crest.
The thoracolumbar fascia is incised lateral to the quadratus lumborum and erector spinae muscles, which are retracted medially. The transversalis fascia is then divided to expose the paranephric fat. An advantage of this approach is that it avoids transection of the abdominal muscles; however, it provides limited access to the hilum, making it difﬁcult to control vascular complications.
The major advantages of retroperitoneal open access include the avoidance of the peritoneal space, which reduces the rate of injury to intraabdominal organs and the risk of postoperative ileus. The major disadvantage is that the renal vessels are not as easily visualized as in a transperitoneal approach.
A laparoscopic nephrectomy can also be performed from either a transperitoneal or retroperitoneal approach.
With a transperitoneal approach, the ﬁrst step is to access the peritoneal cavity and establish a pneumoperitoneum using a Veress needle or open Hasson technique. After adequate insufﬂation of the abdomen, the ﬁrst trocar is placed blindly into the abdomen. The laparoscope is inserted and the abdominal contents inspected for potential injury. Subsequent trocars are then inserted under direct laparoscopic vision. The number and conﬁguration of trocars vary according to individual surgeon preference, but the basic principles of renal triangulation should be observed. The colon is mobilized medially and released of its attachments to the liver or spleen. The kidney is then retracted laterally to facilitate identiﬁcation of the ipsilateral psoas muscle, gonadal vein, and ureter. The renal artery and vein are carefully dissected to determine if there are accessory vessels or segmental vessel branches, then the artery and any accessory branches are ligated using a laparoscopic surgical stapling device. Additional dissection is performed to conﬁdently eliminate all bleeding from the arterial stump. The vein is targeted and ligated in the same manner, then the ureter is divided. The upper pole of the kidney is separated from the adrenal gland as needed. Finally, the kidney is placed in a laparoscopic collection bag and removed through either an extension of a trocar incision or through a separate skin incision (typically Pfannenstiel). The pneumoperitoneum is reduced to ensure adequate hemostasis, and the trocar sites are closed.
With a retroperitoneal approach, the ﬁrst step is to make a small incision over the tip of the twelfth rib. A surgical clamp is then used to puncture the thoracolumbar fascia and enter the retroperitoneum. Manual dissection is performed to free additional space, and the psoas muscle is located using tactile feedback. Next, a balloon trocar is placed in the space and inﬂated to expand the surgical ﬁeld. The space is then insufﬂated, and additional trocars are inserted. The kidney is mobilized by separating the psoas muscle from the paranephric fat and renal fascia. The renal hilum is then identiﬁed and divided, as noted earlier.
The complications associated with nephrectomy include standard surgical complications, such as bleeding, infection, wound separation, myocardial infarction, cerebral vascular accident, deep vein thrombosis, pulmonary embolus, cardiac dysrhythmia, ileus, and atelectasis. In addition, several complications are speciﬁc to this procedure, including renal insufﬁciency and injury to adjacent organs (perforation of bowel, disruption of retroperitoneal vasculature, pancreatic ductal injury/ ﬁstula formation, pneumothorax).
Laparoscopic approaches in particular can be complicated by visceral or vascular injuries during initial access with the Veress needle or trocars. In addition, patients should always be warned that all laparoscopic cases have the potential for conversion to an open procedure.