**4. Surgical Treatment**

Figure 1

146 Updates in Hemodialysis

contrast enhancement.

a b

There are some suspicious features that deserve follow-up.

do not fall into category II are classified in this group.

**3. 3. Magnetic Resonance Imaging (MRI)**

**Figure 1.** CT images of a 65-year-old man with ACD-associated RCC. a: Unenhancement CT shows multiple small cysts and a mass (arrow). b: At early enhancement phase, the mass (arrow) is slightly and heterogenously enhanced.

Category I. —Simple benign cysts showing homogeneous water content, and a sharp interface with adjacent renal parenchyma, without wall thickening, calcification, or enhancement.

Category II. — Cystic lesions with one or two thin (≤1 mm thick) septations or thin, fine calcification in their walls or septa and hyperdense benign cysts with all the features of category I cysts except for homogeneously high attenuation. A benign category II lesion must be 3 cm or less in diameter and have one quarter of its wall extending outside the kidney, without

Category IIF. — Minimally complicated cysts that need follow-up. This group is not well defined by Bosniak originally and consists of lesions that are not classified into category II.

Category III. — True indeterminate cystic masses that need surgical evaluation but prove to be benign in many cases. They may show uniform wall thickening, a multilocular nature with multiple enhancing septa, thick or irregular peripheral calcification. Hyperdense lesions that

Category IV. —Lesions with uneven or contrast-enhanced thick wall, contrast-enhanced or

Recently, MRI is one of topics in diagnosis of ESRD-related RCC. Some studies have reported the usefulness of diffusion-weighted MRI in differentiating RCC from benign cyst, without the use of contrast material [43-46]. Diffusion-weighted imaging (DWI) is a noninvasive functional modality using strong bipolar gradients to create a sensitivity of the signal to the thermally-induced Brownian motion of water molecules and in vivo measure‐ ment of molecular diffusion [47]. This imaging technique has been applied to the diagno‐ sis of cancer [48]. The apparent diffusion coefficient (ADC) is a quantitative parameter of the degree of diffusion, which is calculated from several DWI images of different *b* values. RCC showed a tendency toward higher signal intensities (SIs) with lower ADC values on DWI obtained at high *b* values than benign cysts (Fig. 2). Akita et al. [14] reported 10 RCCs

large nodules in the wall, or clearly solid components in the cystic lesion.

The principle strategy for RCC in dialysis patients is radical nephrectomy (RN). On a nation‐ wide survey in the United States, ESRD-associated RCC patients undergoing RN showed improved survival compared with those not receiving RN [50]. RN is the established surgical approach for conventional RCC. This surgical procedure originally included early vascular control of the renal hilum, removal of the kidney with the Gerota's fascia, removal of the ipsilateral adrenal gland, and a regional lymph node dissection. Although the true benefits of adrenalectomy and regional lymph dissection in patient without enlarged nodes have been a subject of continuing controversy, the principles of early vascular control and removal of the kidney with a wide margin of Gerota's fascia remain the standard of care.

The surgical risk of patients with ESRD is classified as physical status 3 or greater, according to the American Society of Anesthesiologist (ASA) classification [51]. ASA physical status is reported to be a predictor of postoperative outcomes [52]. Therefore, safer and less invasive surgery is recommended for ESRD-associated RCC patients to avoid postopera‐ tive systemic complications. Reported series of minimally invasive RN in ESRD patients are listed in Table. 1.


LRN, laparoscopic radical nephrectomy; GasLESS, gasless laparoendoscopic single-port surgery; TP, transperitoneal; RP, retroperitoneal; EBL, estimated blood loss; OT, operative time.

**Table 1.** Surgical outcomes of minimally invasive surgery for renal cell carcinoma in ESRD patients.

#### **4. 1. Laparoscopic surgery**

Laparoscopic radical nephrectomy (LRN) is a minimally invasive surgical procedure for malignant tumors of the kidney. Clayman et al. first described the successful laparoscopic nephrectomy in 1991 [53]. This was one of the greatest milestones in the history of minimally invasive surgery in that a large solid organ could be removed without an incision of equal or greater size. The utility of the laparoscopic procedures has been verified at many institutions with far less morbidity when compared to open surgery. Many kidney surgeries are currently available laparoscopically [54] via transperitoneal or retroperitoneal approach. Transperito‐ neal approach has advantages of being a very familiar approach with easily recognizable anatomy and a much larger working space. Some investigators mentioned that advantages of retroperitoneal LRN include quicker access to the renal hilum, easier dissection in obese individuals, the avoidance of intraperitoneal injury, and less interference with respiratoty and hemodynamic functions [55]. In regard to the best approach for performing RN, both retro‐ peritoneal and transperitoneal approaches showed similar oncological outcomes in the two randomized control studies [56, 57]. For RCCs in ESRD patients, LRN also showed feasible and acceptable surgical outcomes [58-62], including bilateral cases [63].

#### **4. 2. Gasless Laparoendoscopic Single-port surgery (GasLESS)**

Gasless laparoendoscopic single-port surgery (GasLESS) is gasless (no CO2 gas insufflation) single-port retroperitoneoscopic surgery that was initiated in the late 1990s in Japan. GasLESS is also referred to as minimum incision endoscopic surgery. Kihara et al. first described GasLESS radical nephrectomy (GasLESS-RN); initially minimum incision of 4 or 5 cm is made on the tip of the 12th rib. The length of incision, which narrowly permits extraction of the kidney with perinephric fat, depends on the size of the specimen (Fig. 3). A wide working space is then made through the port by separating anatomical planes extraperitoneally and displacing the peritoneum and the kidney using retractors specialized for GasLESS [64-67]. This operation was certified by the Japanese government as an advanced surgery in 2006, and it has been covered by the Japanese universal health insurance system since 2008. Because of gasless surgery, GasLESS-RN is safely performed for patients with respiratory and circulatory comorbidities compared to LRN. Indeed, feasibility, safety and favorable surgical outcomes of GasLESS-RN were reported for RCC patients [68] [69] including ESRD-associated RCC patients [61, 62]. GasLESS-RN is also indicated for RCC patients on continuous ambulatory peritoneal dialysis because the peritoneum remains intact after GasLESS-RN. Recently, GasLESS-RN incorporates a three-dimentional endoscope and a head mounted display system (3D-HMD system), which enhances safety of surgical procedures and facilitates their fluidity via a coin-sized tiny single port [60] (Fig. 4).

**Operation Authors(publication year) Number of renal units**

retroperitoneal; EBL, estimated blood loss; OT, operative time.

**4. 1. Laparoscopic surgery**

148 Updates in Hemodialysis

**Approach**

TP RP

LRN Yamashita et al. (2012) [61] 39 1 38 157 240

LRN Sanli et al. (2010) [62] 20 4 16 111 133

LRN Ghasemian et al. (2005) [63] 20 20 0 164 390

LRN Gulati et al. (2003) [59] 6 4 2 120 294

LRN Iwamura et al.(2001) [58] 6 0 6 58 162

GasLESS Masuda et al. (2011) [72] 57 0 57 218 170

**Table 1.** Surgical outcomes of minimally invasive surgery for renal cell carcinoma in ESRD patients.

and acceptable surgical outcomes [58-62], including bilateral cases [63].

**4. 2. Gasless Laparoendoscopic Single-port surgery (GasLESS)**

LRN, laparoscopic radical nephrectomy; GasLESS, gasless laparoendoscopic single-port surgery; TP, transperitoneal; RP,

Laparoscopic radical nephrectomy (LRN) is a minimally invasive surgical procedure for malignant tumors of the kidney. Clayman et al. first described the successful laparoscopic nephrectomy in 1991 [53]. This was one of the greatest milestones in the history of minimally invasive surgery in that a large solid organ could be removed without an incision of equal or greater size. The utility of the laparoscopic procedures has been verified at many institutions with far less morbidity when compared to open surgery. Many kidney surgeries are currently available laparoscopically [54] via transperitoneal or retroperitoneal approach. Transperito‐ neal approach has advantages of being a very familiar approach with easily recognizable anatomy and a much larger working space. Some investigators mentioned that advantages of retroperitoneal LRN include quicker access to the renal hilum, easier dissection in obese individuals, the avoidance of intraperitoneal injury, and less interference with respiratoty and hemodynamic functions [55]. In regard to the best approach for performing RN, both retro‐ peritoneal and transperitoneal approaches showed similar oncological outcomes in the two randomized control studies [56, 57]. For RCCs in ESRD patients, LRN also showed feasible

Gasless laparoendoscopic single-port surgery (GasLESS) is gasless (no CO2 gas insufflation) single-port retroperitoneoscopic surgery that was initiated in the late 1990s in Japan. GasLESS is also referred to as minimum incision endoscopic surgery. Kihara et al. first described GasLESS radical nephrectomy (GasLESS-RN); initially minimum incision of 4 or 5 cm is made on the tip of the 12th rib. The length of incision, which narrowly permits extraction of the kidney

LRN Bird et al. (2010) [60] 16 16 0 153 unknown

**Mean EBL (ml) Mean OT (min)**

**Figure 3.** Extraction of a surgical specimen of ACD-associated RCC via a single port in a 65-year-old man treated with GasLESS RN.

**Figure 4.** Scenery of GasLESS via a coin-sized port using the 3D-HMD system.

**Figure 5.** Pathology of ACD-associated RCC in a 65-year-old man. a: Macrophotograph. b: Microphotograph. The tu‐ mor tissue contains oxalate crystals.

### **4. 3. Robotic Radical Nephrectomy**

At present, the affirmative opinion for robotic radical nephrectomy has not been published. Hemal et al. [70] reported a prospective comparison of robotic and laparoscopic radical nephrectomy for non-ESRD RCCs. They concluded that there were no benefits of robotic radical nephrectomy observed over LRN for localized RCC.

#### **4. 4. Partial nephrectomy**

Partial nephrectomy (PN) is a standard of care for small RCC in patients without ESRD. PN offers better postoperative renal function than RN. RCC in ESRD patients has not yet been reported. However, PN would be beneficial for ESRD patients who have small RCC and still maintain urine production. These patients would have to strictly restrict water intake due to reduced urine output when they undergo RN, which impairs their quality of life. PN might be a viable option for a subset of ESRD patients considering their postoperative quality of life.
