Robotic Partial Nephrectomy

Contraindications

1. Contraindications to laparoscopic surgery
2. History of extensive abdominal or pelvic surgery
3. Morbid obesity
4. Extremely large tumor

Advantages to Robotic Approach

• Compared to laparoscopic approach (2014 meta-analysis[1])
  • Significantly lower rate of conversion to open surgery, conversion to radical surgery, shorter warm ischemia time, smaller change of estimated glomerular filtration rate, and shorter length of stay
  • No significant differences in complications of Clavien-Dindo classification grades 1-2, Clavien-Dindo classification grades 3-5, change of serum creatinine, operative time, estimated blood loss, and positive surgical margins
• Compared to open approach (2022 meta-analysis [2])
  • Significantly lower rates of blood loos, length of stay, and postoperative complications
  • No significant differences in operative time, warm ischemia time, positive surgical margins, preoperative eGFR, postoperative eGFR and intraoperative complications

Pre-operative Preparation

• For endophytic tumors, obtain pre-operative ultrasound.
  • If tumour not visible on pre-operative ultrasound, consider radical nephrectomy as intra-operative ultrasound to identify tumour will unlikely be successful.
• Hold/bridge anticoagulation medications prior to surgery
  • ASA 7 days
  • Clopidogrel 5 days
  • Apixaban 2 days
• Pre-operative testing
  • Urinalysis +/- culture

Steps of procedure

• Position: Ipsilateral (tumor side up), modified flank/lateral decubitus at approximately 60-90° (if left sided, 90° so that spleen can fall; if right-sided, less than 90°)
  • Some will flex bed (midpoint of inferior aspect of ribcage and superior aspect of pelvic bone is at break of bed)
• Venous thromboembolism prophylaxis
  • Compression stockings
  • Heparin
• Antibiotics
  • 2g cefazolin (900 mg clindamycin, if penicillin allergic)
• Surgical plan:
  • Number of ports: 5 (6 if right-sided) (variations possible, depending on institution equipment and surgeon preference)
    • 4 robot ports + 1 assistant port +/- 1 liver retractor for right-sided tumors
      • Arm 1: bipolar graspers
      • Arm 2: camera
      • Arm 3: monopolar scissors
      • Arm 4: prograsps
  • Location of ports:
    • All ports are placed in a straight line lateral to the the lateral border of the ipsilateral rectus abdominus muscle. This line may translate laterally (obese patient, lateral tumor) or medially (skinny patient, medial tumor), depending on patient and tumour characteristics
      • Port placement medial to the rectus border risks injury to the epigastric vessels.
    1. Robotic Arm 1 (8 mm): 2 fingerbreadths below the costal margin
    2. Camera/Robotic Arm 2 (12 mm): 1 handbreadth inferior to Robotic Port 1
    3. Robotic Arm 3 (8 mm): 1 handbreadth inferior to Robotic Port 2
    4. Robotic Arm 4 (8 mm): 1 handbreadth inferior to Robotic Port 3
    5. Assistant (12 mm): half-way between camera and Robotic Arm 1, medial to these ports
    • If right-sided, additional 5 mm trocar placed just inferior to xiphoid process for liver traction. Use Allis clamp to hold on abdominal wall and retract liver away from surgical field.
      • Depending on liver anatomy, liver retractor may need to be placed in contralateral side.
  • Step by step:
    • Patient positioning, antiseptic preparation, draping. Insert foley catheter. Position patient. Pressure points should be padded. Axillary roll should be placed (under the upper chest, at a level inferior to the tip of the scapula, rather than under the axillary region[3]) to prevent neuropraxia. An axillary roll is not required if the patient is tilted at the 45° angle and not lying directly on his or her axilla[4]. Arm boards for arms. Secure patient to operating table.
    • Veress needle access. Commonly where camera port will be. Alternatives: umbilicus or Palmer's point (3 cm below the left costal margin and in the midclavicular line). Confirm appropriate placement with saline test.
    • Achieve pneumoperitoneum. Have gas on low flow and determine opening pressure. If pressures are low (< 10 mmg Hg), increase to high flow. As the pressure slowly rises to 20, the port sites are prepared.
    • Insert ports. Once at 20mm Hg, the first port, the assistant port is placed through a 12 mm transverse incision followed by the remaining ports all under direct vision. A 30° robotic camera looking upward facilitates placement of the other trocars. Once all ports are positioned, AirSeal is installed and activated and the pneumoperitoneum is reduced to 12-15 mm Hg for the procedure.
    • Dock robot
      • If Xi
        • Attach camera port to robot. Insert and attach camera. Target camera to kidney. Hold camera port steady and allow robot to adjust. Attach remaining ports to robot.
      • Insert instruments into arms (Robot Arm 1 - bipolar graspers, Robot Arm 3 - monopolar scissors, Robot Arm 4 - Prograsp fenestrated graspers). Connect cords. Advance arms under vision.
    • Medialize bowel to expose retroperitoneum. Incise peritoneum lateral to the white line of Toldt. Use blunt and sharp dissection to develop plane anterior to Gerota fascia and posterior to the mesocolon. Release attachments to the spleen and liver as needed.
      • On the right side, goal is to identify the IVC; there is no need for extensive mobilization of the bowel to expose the renal hilum. During the mobilization of the duodenum medially, the use of cautery is minimized.
      • On the left side, mobilize the spleen completely to avoid potential splenic injury. Use hand over hand motion. Be careful of splenic artery and pancreas. When developing space between spleen and kidney, use left hand under spleen to protect spleen. For efficiency, develop this space completely, before continuing to mobilize the colon.
      • Use the Prograsp to retract the kidney laterally after sufficient medialization of the bowel.
    • Identify ureter. The mid-ureter is identified along the anterior aspect of the psoas. Once identified, a dissection plane is created medial and parallel to the ureter, with careful identification of the gonadal vein. The plane is developed superiorly along the psoas muscle with anterior elevation of the ureter and/or gonadal vein to identify the renal hilum. Use the Prograsp fenestrated graspers for anterior retraction.
      • The gonadal vein is an important anatomic landmark when proceeding toward the renal hilum; the renal vein can be identified by tracing the gonadal vein proximally to its insertion in the renal vein on the left side or to its insertion in the inferior vena cava just caudal to the hilum on the right side.
      • On the right side, the gonadal vein is kept medially toward the vena cava, whereas on the left side, the gonadal vein is lifted along with the left ureter to expose the lower margin of the left renal hilum.
      • Proximally, the gonadal vessels are medial to the ureter. The gonadal vessels descend laterally and cross anterior to the ureter, “water under the bridge”, a third of the way to the bladder.
        • The gonadal vessels cross the left ureter after running parallel to it for a small distance
    • Identify renal hilum. Identify renal artery. Renal artery only needs enough dissection to allow bulldog to clamp it i.e. circumferential dissection is not needed. It is important not to miss early arterial branching that is more common on the right side, especially if a venous occlusion is planned, as this may lead to kidney congestion and may result in more bleeding. Advantages of renal vein clamping: decreased bleeding during tumor resection; disadvantage: more dissection needed, potentially increasing risk. Consider renal vein clamping for (3) right-sided tumors, central tumors, and large tumors. Place clamp(s) in the vicinity.
    • Identify tumour. Make an incision in Gerota's fascia and dissect through fat in an area far from the tumor to find the kidney capsule. When near capsule, grasp fat and use cautery on edge of fat plane, not kidney edge. Continue to clear fat off renal surface, aiming to work in fat planes. a clue that one is approaching the tumor area is the presence of adhesions. Stay superficial to capsule since capsule is strength layer of repair. Sticky fat can be tedious. Bipolar helpful for vessels in fat. Use ultrasound to confirm location of tumor (green dot indicates proximal aspect of probe). The fat is then cleared circumferentially around the mass, allowing for visualization of 1–2 cm of normal parenchyma for future renal reconstruction. All attempts should be made to leave the overlying Gerota’s fascia atop the mass to assist in histopathologic staging and also to use as a handle for retraction. Use ultrasound to identify location, depth, and borders of tumor. To define the border of the tumor, the ultrasound probe is oriented parallel to the tumor border. Increase cautery settings to 50/50 and score edges of tumor + margin with scissors intermittently, not circumferentially. Check with doppler ultrasound that there is flow in multiple places.
    • Pre-clamp checklist.
      • Confirm stable patient status with anesthesia
      • Increase pneumoperitoneum to 20 mm Hg
      • Confirm sufficient gas in tank
      • Confirm cautery settings (usually 40/40)
      • Confirm all sutures/rescue sutures are available
      • Ensure bedside assist has access to field and all ports are not displaced
      • Get all sutures in the field (Two 22 or 15 cm (depending on defect size) 2-0 Stratafix on a CT-1 needle with Hem-o-lok Weck clip in the loop of the suture)
      • Announce sequence of steps
    • Cut tumour.
      • Apply bulldog(s)
      • Confirm absence of flow in multiple places. If still flow, need to identify additional arterial inflow. After confirming absence of flow, assistant removes doppler and replaces with suction.
      • Start cutting tumor around 5-6 o clock with cold scissors (may need to use heat over fat that covers edge). Use one scissor length excursions. If excessive bleeding, may have missed an artery. Continue cutting tumor circumferentially, if possible, as allows more mobility. Initially, closer to edge, cut with cold scissors to enter enucleation plane. Once plane entered, use peel and lift. Some attachments/vessels may need bipolar/coagulation and then cut with scissors. Use left hand to retract tumor. The bedside assistant uses suction to clear the resection bed, enabling improved visualization while applying slight counter retraction, as needed.
      • After excising tumor, place tumor in medial lower quadrant.
      • Use bipolar or hot scissors for any active vessels. 
    • Renorrhaphy
      • Switch to needle drivers. Use one hand to compress bleeding while other hand is changed to needle driver. When needle driver in, replace compression and switch other hand to needle driver
      • Deep layer closure. Use 22cm 2-0 Stratafix on a CT-1 needle with Hem-o-lok Weck clip in the loop of the suture. Anchor on the renal capsule outside of the defect by taking outside-in bite. Inside bite should be at the distal apex of deeper bed.
      • Using same stitch, perform deep layer closure by passing suture through cortical layer of the renal defect. Bite is with right hand from one side to another, big bites taken in 1. Use right hand to first anchor stitch in position, then regrab proximally to manipulate in good direction. Slow, controlled movements avoid tearing. Use left hand to lift prior suture but not too tight. First throw is taken on opposite side of anchor. 2-3mm travel.
        • If entry into collecting system, incorporate these into the bites. Sew in the most ergonomic fashion. DO NOT TIGHTEN. Keep running until proximal aspect of deep defect. Exit the contralateral side. Secure with a Hem-o-lok Weck clip. Tighten slightly and break needle and ensure assistant removes needle.
      • Superficial layer closure. Use 22cm 2-0 Stratafix on a CT-1 needle with Hem-o-lok Weck clip in the loop of the suture. Anchor on the renal capsule outside of the defect by taking outside-in bite. Then inside-out bite. Enter and exit outside the renal defect beyond the distal apex of defect. Place hem-o lock. Cinch. Take next bite, and place hem-o-lock. Put away superficial stitch.
      • Tighten deep layer. Gradually tighten deep layer suture starting distally and working towards proximal apex. Advance suture with right hand, hold in place with left. Repeat then move onto next suture. Tighten hemolock on exit +/- entry of deep layer. Consider placing additional hemolock for vicryl, not needed for braided sutures such as stratafix.
      • Continue superficial layer. Tighten superficial layer. When tightening hem-o-locks, advance suture so that it slides in middle. The ultimate (last) hem-o-lok may be held in place by spreading the needle driver tips, but for all penultimate ones the hem-o-lock should be held in center with grasp of needle driver. Subsequent bites should be taken in two, outside-in, inside-out. Ensure bites are not superficial as this suture should close both the cortical and medullary layers. After existing parenchyma, secure layer with Hem-o-lok Weck clips. Slightly tighten ultimate suture, but only cinch penultimate suture. Continue running to proximal edge of defect and exit on contralateral side.
      • Tighten superficial layer.
      • Tighten further.
      • Tighten deep layer Hem-o-Loks at distal ends of renorrhaphy  
      • Remove clamp. Assess kidney for bleeding and obtain additional hemostasis as needed.
      • Decrease pneumoperitoneum 10 mm Hg and reassess for bleeding.
      • Cut and remove needles.
      • Remove bulldogs
      • Obtain further hemostasis, may need scissors to coagulate in some areas
    • Closure
      • Place tumour in bag. A laparoscopic entrapment sac is introduced by the assistant; the specimen is placed in the sac and removed from camera port, if small, or assistant port, if larger. Care must be taken to make the extraction incision large enough to avoid fracturing the specimen, possibly preventing accurate histopathologic examination for margin status and staging.
      • +/- insert drain through arm 4
      • Undock robot.
      • Close port sites and extraction site. Consider closing fascia for extraction site

Complications

• Intra-operative
  • Bleeding
  • Injury to adjacent organ (bowel, diaphragm, liver, spleen, pancreas)
• Early post-operative
  • Infection
  • Re-operation due to
    • Bleeding
    • Wound dehiscence
• Late post-operative
  • Incisional hernia

References

• Davila, Hugo H., Raul E. Storey, and Marc C. Rose. "Robotic-assisted laparoscopic radical nephrectomy using the Da Vinci Si system: how to improve surgeon autonomy. Our step-by-step technique." Journal of robotic surgery 10.3 (2016): 285-288.
• Caputo, Peter A., et al. "Robotic‐assisted laparoscopic nephrectomy." Journal of surgical oncology 112.7 (2015): 723-727.