Partial nephrectomy

NEPHRON SPARING SURGERY

1. PARTIAL NEPHRECTOMY DR BRIGHT SINGH MBBS,MS,MCh ( Sur.Onco ), D.Lap,FIAGES,FMAS,FAIS MALABAR CANCER CENTRE,KERALA ,INDIA

2. HISTORY The first partial nephrectomy was performed in 1884 by Wells for removal of a perirenal fibrolipoma In 1887, Czerny was the first to use partial nephrectomy for excision of a renal neoplasm

3. DEFINITION Complete local resection of diseased renal parenchyma leaving the largest possible amount of normal functioning parenchyma in the involved kidney

4. SURGICAL TECHNIQUE   Anatomic Considerations- Renal Arterial anatomy   The kidney has four constant vascular segments, which are termed apical, anterior, posterior, and basilar Each of these segments is supplied by one or more major arterial branches Although the origin of the branches supplying these segments may vary, the anatomic position of the segments is constant All segmental arteries are end arteries with no collateral circulation; therefore, all branches supplying tumor -free parenchyma must be preserved to avoid devitalization of functioning renal tissue.

5. The posterior segmental artery - supply entire posterior segment, involving all of the posterior portion of the kidney except that taken up by the polar segments   The posterior segmental artery crosses behind the upper portion of the pelvis at a point very close to the origin of the superior calyx [site of injury during mid-kidney and lower-pole resection]  

6. The renal venous drainage system differs significantly from the arterial blood supply in that the intrarenal venous branches intercommunicate freely between the various renal segments Ligation of a branch of the renal vein, will not result in segmental infarction of the kidney because collateral venous blood supply This is important clinically because it enables to obtain surgical access safely to tumors in the renal hilus by ligating and dividing small adjacent or overlying venous branches. A true avascular line-BRODEL- exists at the junction of the anterior and posterior segments on the posterior surface of the kidney. Renal venous anatomy

7. Intrarenal collecting system There are 8 to 10 major calyces that open into the renal pelvis apical segment - one major calyx - receives two minor calyces[lateral and medial] basilar segment - one major calyx- receives two minor calyces[anterior and posterior] anterior segment -three major calyces which enter the renal pelvis at a 20-degree angle to the midfrontal plane posterior segment -three major calyces which enter the renal pelvis at a 75-degree angle to the midfrontal plane

8. INTRAOPERATIVE RENAL ISCHEMIA Temporary occlusion of the renal artery is necessary in NSS Temporary arterial occlusion not only diminishes intraoperative renal bleeding but also improves access to intrarenal structures by causing the kidney to contract and by reducing renal tissue turgor

9. Renal artery occlusion cause reductions in medullary blood flow with reduction in oxygen delivery to the tubular structures This will lead to cellular injury due to imbalance between oxygen delivery and demand Endothelial injury due to leukocyte activation [cytokines, chemokines , eicosanoids ] and release of vasoactive substances >> swelling and injury of the endothelial cell

10. Renal Tolerance to Warm Ischemia The extent of renal damage after normothermic arterial occlusion depends on the duration of the ischemic insult The warm ischemic time is 30 minutes If it beyond 30 minutes, the recovery of renal function is either incomplete or absent It affects mostly the proximal tubular cells, whereas the glomeruli and blood vessels are generally spared The solitary kidney is more resistant to ischemic damage than the paired kidney Presence of an extensive collateral vascular supply increases the tolerance to temporary arterial occlusion

11. The method employed to achieve vascular control of the kidney is the important determinant of renal ischemic damage The impairment is least when the renal artery alone is continuously occluded Continuous occlusion of the renal artery and vein for an equivalent time interval is more damaging,because it prevents retrograde perfusion of the kidney through the renal vein and may also produce venous congestion of the kidney Intermittent clamping of the renal artery is also more damaging than continuous arterial occlusion,because of the release and trapping of vasoconstrictor agents within the kidney Manual renal compression to control intraoperative hemorrhage is more deleterious than simple arterial occlusion

12. Prevention of Ischemic Renal Damage General measures P reoperative and intraoperative hydration P revention of hypotension A voidance of unnecessary manipulation or traction on the renal artery I ntraoperative administration of mannitol These factors ensure optimal perfusion with an absence of cortical vasospasm at the time of arterial occlusion, which allows uniform restoration of blood flow throughout the kidney when the renal artery is unclamped

13. Mannitol is most effective when it is given 5 to 15 minutes before arterial occlusion (20%-1mg/kg) It increases renal plasma flow, decreases intrarenal vascular resistance, minimizes intracellular edema , and promotes an osmotic diuresis when renal circulation is restored Protective measures Local hypothermia is the most effective and commonly employed method Lowering renal temperature reduces energy-dependent metabolic activity of the cortical cells, with a resultant decrease in both the consumption of oxygen and the breakdown of adenosine triphosphate The optimum temperature for hypothermic in situ renal preservation is 15°C

14. It is difficult to achieve uniform cooling to this level [15`C] because of the temperature of adjacent tissues and need to exposed a portion of the kidney to perform the operation The temperature of 20°C to 25°C is easier to maintain with renal preservative effect This level of hypothermia provides complete renal protection from arterial occlusion of up to 3 hours

15. In situ renal hypothermia External surface cooling Perfusion of the kidney with a cold solution instilled into the renal artery[invasive] These two methods are equally effective Surface cooling of the kidney is a simpler and widely used method surrounding the kidney with a cold solution [or] applying an external cooling device to the kidney

16. Ice-slush cooling The mobilized kidney is surrounded with a rubber sheet on which sterile ice slush is placed to completely immerse the kidney This method is to keep the entire kidney covered with ice for 10 to 15 minutes immediately after the renal artery is occluded This amount of time is needed to obtain core renal cooling to a temperature of 20°C Extent up to 2- 4 hrs without ischemic injury

17. The following details must be observed for surgical planning 1. Nephrometry score, especially the location of the mass and its proximity to the hilar vessels. 2. Vascular anatomy such as the presence of multiple renal arteries and veins, early renal arterial bifurcations, and variants of the renal hilar vasculature. 3. Amount of perinephric fat and the presence (or absence) of perinephric stranding. 4. Presence (or absence) of other renal masses in both the ipsilateral and contralateral kidneys. 5. Proximity of the ureter to the renal tumors , especially for lower pole masses. 6. Renal anomalies such as pelvic kidneys and horseshoe kidneys.

18. Noncontrast CT image detecting macroscopic fat indicative of angiomyolipoma Contrast‑enhanced study (magnetic resonance imaging, CT, or renal perfusion/ excretion scan) indicating bilateral renal function. “Renal protocol” CT imaging, consists of 3 imaging sequences including precontrast , corticomedullary phase, and late nephrogenic excretory phase but cannot determine if the mass is benign or malignant. Ultrasound can fully characterize cystic lesions and serves as an effective template for intraoperative ultrasound which can be highly effective in locating small subcortical renal tumors

19. What does these score depict? These score depict the level of difficulty and eventual success in doing 80 of partial Nephrectomy esp. By Lap/Robotic. These score hardly matters for open Sx but still are applicable to open Surgeries also.

20. INDICATIONS FOR SURGERY   Situations in which radical nephrectomy would render the patient anephric , with subsequent immediate need for dialysis Unilateral RCC and a functioning opposite kidney when the opposite kidney is affected by a condition that might threaten its future function, such as calculus disease, chronic pyelonephritis , renal artery stenosis , ureteral reflux, or systemic diseases (e.g., diabetes and nephrosclerosis )

21. Indications : for partial Nx Any T1 (0- 7 cm) even with normal functioning contralateral kidney. A tumor in a solitary kidney, Bilateral kidney tumors If Contralateral kidney is threatened / affected by stone / CKD / HTN WILMS TUMOUR. Contra indications Nodal mets positive IVC thrombus / Renal vein thrombus positive PC system involvement Renal hilar involvement

22. Timing of surgery in bilateral RCC   After 1 month, second partial nephrectomy or a radical nephrectomy on the opposite kidney In bilateral, small, synchronous RCCs, bilateral simultaneous partial nephrectomies are also performed.

23. APPROACHES OPEN NSS. LAPAROSCOPIC NSS. ROBOTIC NSS. ABLATIVE PROCEDURES NSS.

24. LNSS POSITION MODIFIED LATERAL DECUBITUS POSITION IPSILATERAL CHEST AND SHOULDER ARE PLACED 30- TO 45-DEGREES OFF THE TABLE. OPEN-ENDED 5-FR CATHETER IS PASSED CYSTOSCOPICALLY UP THE IPSILATERAL URETER. INJECTING METHYLENE BLUE ONCE THE COLLECTING SYSTEM IS TRANSECTED CAN AID IN CLOSURE.

25. Anaesthesia : G/A Deploy : RetroGrade Catheter + Foleys Position : Lateral flank position Approach : Extra-pleural, extra-peritoneal flank Incision : 11th Rib tip incision Procedure : Open the retroperitoneal space Loop the ureter : Deploy self retaining retractor Dissect the hilum Loop the artery and vein Start mannitol (20% in 100ml) so 300 ml - 60 mg

26. Remove the perinephric fat around the normal parts of kidney. Don’t remove the perinephric fat over tumour Clamp the artery with bull dog clamp Cut a hole a plastic sheath and place kidney into it Put ice slush all around for 15 min Time up – displace the ice Mark the tumor and excise with caultry Visible open blood vessels are sutured with figure of 8 sutures Send for frozen section – NO NEED Push 10ml methylene blue 1:1 diluted through RGC If any calyceal system opening is seen – close it Frozen section negative (if sent for frozen ) Close kidney over afterHemostasis achieved Kidney fixed to posterior musculature to avoid flipping Release clamp

27. TECHNIQUES ENUCLEATION POLAR SEGMENTAL NEPHRECTOMY WEDGE RESECTION TRANSVERSE RESECTION EXTRACORPOREAL PARTIAL NEPHRECTOMY WITH RENAL AUTOTRANSPLANTATION.

28. POLAR SEGMENTAL NEPHRECTOMY Indicated in tumor confined to the upper or lower pole of the kidney Performed by isolation and ligation of the segmental apical or basilar arterial branch The apical artery is dissected, ligated , and divided An ischemic line of demarcation appears on the surface of the kidney and outlines the segment to be excised METHYLENE BLUE CAN BE DIRECTLY INJECTED DISTALLY INTO THE LIGATED APICAL ARTERY TO BETTER OUTLINE THE LIMITS

29. POLAR NEPHRECTOMY The kidney is mobilized within Gerota's fascia while the perirenal fat around the tumor is left intact The parenchyma around the tumor is divided with a combination of sharp and blunt dissection After excision of the tumor , the remaining transected blood vessels on the renal surface are secured with figure-of-eight 4-0 chromic sutures

30. WEDGE RESECTION Indicated in peripheral tumors on the surface of the kidney, particularly ones that are larger or not confined to either renal pole This technique is associated with heavier bleeding It should be done with temporary renal arterial occlusion and surface hypothermia. In a wedge resection, the tumor is removed with margin of normal renal parenchyma

31. Wedge resection for a peripheral tumor RENAL DEFECT CLOSED BY TWO WAYS. CLOSED ON ITSELF BY APPROXIMATING THE TRANSECTED CORTICAL MARGINS WITH SIMPLE INTERRUPTED 3-0 CHROMIC SUTURES AFTER PLACEMENT OF A SMALL PIECE OF OXYCEL AT THE BASE OF THE DEFECT. PERIRENAL FAT MAY SIMPLY BE INSERTED INTO THE BASE OF THE RENAL DEFECT AND SUTURED TO THE PARENCHYMAL MARGINS WITH INTERRUPTED 4-0 CHROMIC SUTURES

32. TRANSVERSE RESECTION It is done to remove large tumors that involve the upper or lower portion of the kidney Major branches of the renal artery and vein supplying the tumor -bearing portion of the kidney are identified in the renal hilum , ligated , and divided

33. Transverse resection for a tumor involving the upper half of the kidney

34. PARTIAL NEPHRECTOMY FOR CENTRAL TUMORS For patients with central tumors , complete delineation of the renal arterial and venous supply is mandatory for surgical planning.this information can be obtained with three-dimensional CT scanning It is performed after temporary occlusion of the renal artery and vein The tumor is mobilized and isolated as much as possible by dissecting away adjacent segmental renal vessels The main renal vein is mobilized and retracted in either direction to expose a central tumor by ligation and division of small adjacent or overlying venous branches

35. Mobilization of the left renal vein to exposure tumor in the renal hilum by ligation and division of small renal venous branches.

36. SIMPLE ENUCLEATION SURROUNDED BY A DISTINCT PSEUDOCAPSULE OF FIBROUS TISSUE ( VERMOOTEN, 1950. CIRCUMFERENTIAL INCISION OF THE RENAL PARENCHYMA AROUND THE TUMOR AT ANY LOCATION, OFTEN WITH NO VASCULAR OCCLUSION. HIGHER RISK OF LEAVING RESIDUAL MALIGNANT CELLS IN THE KIDNEY. Enucleation is indicated only in von Hippel–Lindau disease and multiple low-stage encapsulated tumors involving both kidneys

37. EXTRACORPOREAL PARTIAL NEPHRECTOMY AND AUTOTRANSPLANTATION It was described by Calne 1973, Gittes and McCullough 1975 Indicated in large complex tumors involving the renal hilum ADVANTAGES Optimum exposure Bloodless surgical field Maximum conservation of renal parenchyma Greater protection of the kidney from prolonged ischemia

38. DISADVANTAGES longer operative time need for vascular and ureteral anastomoses increased risk of temporary and permanent renal failure PROCEDURE It is performed through a single midline incision The kidney is mobilized and removed outside Gerota's fascia with ligation and division of the renal artery and vein The removed kidney is flushed with 500 mL of a chilled intracellular electrolyte solution and submerged in ice-slush saline solution to maintain hypothermia

39. A, The kidney is removed outside Gerota's fascia. B, The tumor is excised extracorporeally C, Pulsatile perfusion or reflushing is used to identify transected blood vessels D, The kidney is closed on itself

40. After the tumor has been completely resected , the renal remnant may be reflushed or placed on the pulsatile perfusion unit to facilitate identification and suture ligation of remaining bleeding points The defect is closed by suturing the kidney on itself Autotransplantation into the iliac fossa is done by the same vascular technique as for renal allotransplantation . Urinary continuity may be restored with ureteroneocystostomy or pyeloureterostomy with internal ureteral stent Drain is positioned extraperitoneally in the iliac fossa

41. HAEMOSTASIS & COLLECTING SYSTEM CLOSURE AFTER EXCISION OF THE TUMOR, THE REMAINING TRANSECTED BLOOD VESSELS ON THE RENAL SURFACE ARE SECURED WITH FIGURE-OF-EIGHT 4-0 CHROMIC SUTURES. RESIDUAL COLLECTING SYSTEM DEFECTS ARE SIMILARLY CLOSED. WITH THE RENAL ARTERY STILL CLAMPED BUT WITH THE RENAL VEIN OPEN, HYPERINFLATE THE LUNGS AND THEREBY RAISE THE CENTRAL AND RENAL VENOUS PRESSURES.

42. THERMAL ABLATIVE THERAPIES

43. CRYOSURGERY RAPID FREEZING, GRADUAL THAWING, REPETITION OF THE FREEZE-THAW CYCLE. IMMEDIATE CELLULAR DAMAGE AND DELAYED MICROCIRCULATORY FAILURE . ICE FORMATION IN THE EXTRACELLULAR SPACE-HYPEROSMOTIC WATER PERMEATES FROM THE IC COMPARTMENT. LEADING TO INTRACELLULAR SOLUTE CONCENTRATION AND DEHYDRATION, WHICH CAUSE DESICCATION TRAUMA. CONTINUED RAPID SUPERCOOLING LEADS TO CELLULAR DAMAGE—INTRACELLULAR ICE FORMATION. DELAYED MICROCIRCULATORY FAILURE OCCURS DURING THE SLOW THAW PHASE OF THE FREEZE-THAW CYCLE, LEADING TO CIRCULATION ARREST AND CELLULAR ANOXIA

44. RADIOFREQUENCY ABLATION HEAT ABOVE 45°C LEADS TO IRREVERSIBLE CELLULAR DAMAGE, AND TEMPERATURES HIGHER THAN 55°C TO 60°C RESULT IN IMMEDIATE CELL DEATH. RADIOFREQUENCY ABLATION INDUCES EXCITATION OF IONS, FRICTIONAL FORCES, AND HEAT. TEMPERATURES IN EXCESS OF 100°C ARE OBTAINED. DISADVANTAGE IS THAT THE TREATMENT EFFECT IS MORE DIFFICULT TO MONITOR IN REAL TIME—THERE IS NO TRUE “ICE BALL” . PREDICTABLE TARGET ZONE OF UP TO 4.0 CM TO BE TREATED IN MOST CASES.

45. Thermo ablation Advanced age . Significant comorbities . Local recurrence after previous NSS. Multifocal tumors CRYOABLATION & RFA HIFU & CYBERKNIFE A ctive survelliance Small. Well marginated . Homogeneous . Non-cancer causes of death & the risk of intervention Vs Risk of RCC progression(0.28 cm/yr). Serial renal imaging at 6 to 12-month intervals .

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