Introduction

Robot-assisted laparoscopic surgery has radically changed the landscape of minimally invasive surgery during the past 15 years. Its advantages over traditional laparoscopy include a superior magnified, stereoscopic three-dimensional view, 7 degrees of freedom, no fulcrum effect, and improved surgeon ergonomics. This chapter explores the special considerations surgeons must bear in mind while performing robotic surgery.

Patient Selection and Preparation

The preoperative assessment prior to any robotic surgical procedure begins with a thorough patient history and physical examination. All pertinent laboratory workup and radiologic imaging should be thoroughly reviewed with the patient. Medically complex patients with significant cardiac or pulmonary comorbidities should be referred to medical specialists for operative risk stratification and optimization. A satisfactory informed consent should be obtained, informing the patient of the possible risks and benefits associated with the procedure, as well as clearly conveying the possibility that the operation may involve conversion to the traditional laparoscopic or an open approach. A variety of upper and lower urinary tract procedures can be approached robotically, depending on the surgeon’s experience. Specific contraindications to general transabdominal urologic robotic surgery are similar to laparoscopic surgery and include extensive previous abdominal/pelvic surgery or radiation, as well as severe medical comorbidities precluding an operation, such as uncorrectable coagulopathy, severe cardiopulmonary disease, or multiorgan failure. Anatomic anomalies, body habitus, and the specific surgical procedure must be considered when selecting the appropriate robotic surgical system. The da Vinci Xi system (Intuitive Surgical Inc., Sunnyvale, CA) is preferable for multi-quadrant procedures.

Robotic-team Approach

An experienced robotic team is critical to the success of an operation. The sophisticated robotic technology requires a coordinated approach for proper setup of the operating room. A surgical checklist should be conducted to ensure that all pertinent equipment is available and functioning before the start of a case. Prior to the patient’s entrance into the operating room, all critical parts of the da Vinci surgical system, including the surgeon console, patient-side cart, and instrumentation (its associated remaining uses and proper insulation properties), as well as the audio-visual connections, should be deemed functional. Furthermore, particular procedures demand specific positioning of the robotic patient-side cart, anesthesia equipment, and instrument table in relation to the operating table. In addition, some procedures require specific intraoperative equipment; for example, if a procedure is expected to necessitate intraoperative real-time ultrasound, then the surgical team must ensure proper function of the TilePro (Intuitive Surgical Inc., Sunnyvale, CA); this involves the digital output cable from the ultrasound machine being connected to the digital video interface (DVI) or S-video input of the robotic da Vinci console.

Patient Positioning

The basic aim of patient positioning is to allow for maximal access to the surgical target organ without compromising patient safety. For lower urologic tract surgery, such as robotic-assisted laparoscopic radical prostatectomy (RARP) or robotic-assisted laparoscopic cystectomy (RARC), the patient’s arms are secured at the sides and lower extremities are placed in low lithotomy position using Yellofins elite stirrups with Lift-Assist (Allen Medical, Acton, MA) with careful attention paid to avoiding undue hip abduction, flexion, and extension ( Fig. 31.1 ). All pressure points should be carefully padded with care. The patient should then temporarily be placed into a steep Trendelenburg position between 25 and 45 degrees in order to test whether respiratory compliance and effort is tolerated in this position. For robotic transperitoneal renal surgery, our preference is to place the patient in a modified lateral decubitus position (i.e., 45-degree partial flank position) ( Figs. 31.2–31.4 ) and to rotate the table laterally to achieve roughly a 90 degree angle in relation to the floor. In this position, gravity assists with medial mobilization of the large and small bowel. At the beginning of the surgery, in most patients, we rotate the patient to a supine position to establish pneumoperitoneum in the umbilicus. After insertion of the midline trocars, the patient is rotated to a 90-degree lateral position for the rest of the operation. In morbidly obese patients, umbilical and midline trocars are avoided and pneumoperitoneum is obtained laterally. The patient’s ipsilateral arm is padded and taped alongside the chest and abdomen so that it does not interfere with the robotic cephalad arm. The patient’s bottom leg is flexed while the top leg is extended. Adequate padding is essential and placed at all pressure points. The table is mildly flexed to increase the angle between the costal margin and iliac crest, thereby increasing lower abdominal space to utilize a 4-arm robotic approach. For the robotic retroperitoneal renal approach, similar to traditional open renal surgery, the patient is placed in a full lateral decubitus position, and a sub-axillary roll is used to help prevent brachial plexus injuries. Furthermore, the table is flexed fully to allow for maximum retroperitoneal working space.

Appropriate positioning for robotic prostatectomy.

Appropriate positioning for robotic renal surgery in partial flank position.

Appropriate positioning for robotic renal surgery in partial flank position with ipsilateral arm secured in an adducted position at the hip.

Appropriate positioning for robotic renal surgery in full flank position with ipsilateral arm secured in a cephalad position.

Long operative periods in these exaggerated positions predispose the patient to various position-related complications, including ocular manifestations, facial and laryngeal edema, various neuropathies, compartment syndromes, rhabdomyolysis (RM), deep venous thrombosis, and deficiencies in skin integrity.

A recent large, national population-based sample of patients undergoing open and robotic procedures reviewed the rates of eye-related complications. The data revealed that robotic hysterectomy carried a 6.5 times greater risk of experiencing a corneal abrasion than with the open approach; however, there was no statistical difference in corneal abrasion when open prostatectomy patients were compared to robotic prostatectomy patients. Several purported risk factors for corneal abrasions include raised intraocular pressure secondary to prolonged, steep head-down position, corneal exposure and dryness, and mechanical trauma; in this study, African American race served to be a protective factor. Wen et al. conducted an analysis of another large, national inpatient sample of patients who underwent open, laparoscopic, and robotic-assisted prostatectomies and compared the position-related complication rates between them. This study of 175,699 men revealed an overall complication rate of 0.79%, with ocular-related complications (visual disturbances, unilateral eye blindness, and corneal-foreign bodies) being the most common (51% of total complications). The remainder of injuries (49%) were related to nerve lesions, RM, and compartment syndrome. Undergoing a laparoscopic prostatectomy (OR = 2.88) and having multiple comorbidities (OR = 2.34) conferred the greatest statistically significant risks of experiencing a positional injury. In contrast, the robotic approach was not associated with developing a higher rate of position-related complications when compared to the open procedure. Overall ocular complications as well as visually threatening eye complications (i.e., visual loss) proved to be more common in the open group versus the robotic cohort. Development of a positioning complication was found to have a resultant threefold increase in length of stay and fourfold increase in inpatient costs when compared to not incurring a position-related event. The authors conveyed surprise in their analysis of these data, as they initially hypothesized that robotic prostatectomy would carry an increased risk of positioning complications compared to the open approach, resulting from a greater operative length, an association revealed in previous studies. Although this study was not able to account for operative times, its large national sample size suggests generalizable results.

Positioning injuries involving the extremities include brachial plexus injuries as well as peripheral neuropathies. In the Trendelenburg position, inadvertent movement of the patient via gravity is possible; this is especially prone to occur in the obese patient population and can result in neuropathies and potential robotic port site abdominal injuries, incisional widening, and increased postoperative port site pain, as the patient shifts downward on the operating table while the robotic trocars remain in a stationary position. Thus, various surgical immobilization mechanisms have been used to help prevent the patient from sliding downward. Shoulder braces have been identified in several retrospective reviews as a risk factor for brachial plexus injury via compression or stretch, especially with concomitant abduction of the upper extremities to 90 degrees or greater. However, Gainsburg et al. reported no evidence of brachial plexus injury on 575 consecutive RARP patients with the careful application of a horseshoe-shaped shoulder immobilization restraint around the acromio-clavicular joints in patients with a weight greater than 75 kg. Chest straps have also been used to prevent downward shifting of the patient while in steep head-down position; however, this has been shown to further decrease lung compliance and ease of ventilation. Anti-skid foam pads secured to the surgical bed or bean bags are also utilized in some centers with success.

Lower extremity peripheral neuropathies can manifest with postoperative pain, weakness, and sensation deficits/alterations and are thought to be caused by protracted flexion, abduction, and external rotation of the hip joints, or by compression of pressure points. Operative lengths greater than 2–4 hours in the lithotomy position have proved to be a risk factor for the development of lower extremity neuropathies. Interestingly, a higher BMI is proposed to be a protective factor against compression-related neuropathies. The incidence of lower extremity neuropathies appears to be less than 2% in urologic robotic-assisted pelvic surgery; Manny et al. report an incidence of lower extremity neuropathy of 1.7% in patients undergoing RARP or RARC while Koc et al. report an incidence of 1.3% in their series of RARP patients. Furthermore, Warner et al. performed an analysis on a series of 198,461 patients who underwent various surgical procedures in the lithotomy position and reported a 0.028% rate of lower extremity peripheral neuropathy (1 per 3608 patients) most commonly involving a motor neuropathy of the common peroneal nerve (78%). In contrast to the lithotomy position, a split-leg position appears to pose a higher risk for femoral nerve palsy in performing RARP secondary to hyperextension of the hip joint to assist with docking of the patient-side cart. Although a majority of peripheral neuropathies transiently improve several weeks to months postoperatively, some may persist longer and become permanent.

Facial and laryngeal edema are other manifestations of a steep head-down tilt in lower urinary tract robotic surgery. Facial congestion results from a protracted state of steep Trendelenburg position and can be minimized via limiting intravenous fluids during this portion of the procedure; it is important to replete the patient’s intravascular volume prior to conclusion of the surgery. Laryngeal and pharyngeal edema is also implicated with lengthy Trendelenburg positioning, and extreme cases of this can result in respiratory distress occurring after a patient is extubated, necessitating reintubation. Again, somewhat restrictive fluid management (less than 2000 mL) in the lithotomy position is thought to alleviate laryngeal edema.

Postoperative RM and compartment syndromes of the gluteal muscles and lower extremities (well limb compartment syndrome, WLCS) resulting from robotic surgery are exceedingly rare complications and are associated with prolonged exaggerated flank or lithotomy positions. Surgically induced RM is thought to result from prolonged compression of skeletal muscle associated with decreased blood flow, necrosis, possible compartment syndrome, and, ultimately, skeletal muscle breakdown, with subsequent release of myoglobin and creatine phosphokinase (CPK). CPK levels two to three times greater than normal in the proper clinical setting should alert the physician to a possible diagnosis of RM. Patients may experience tenderness at the site of injury, edema, muscle pain, and dark-colored urine, or may alternatively lack symptoms. Acute renal failure may result in 30–40% of patients and is thought to be mediated by reduced glomerular filtration, intratubular heme cast formation with subsequent obstruction, tubular obstruction by precipitated myoglobin, and a direct nephrotoxic effect via ferrihemate. Aggressive fluid hydration is recommended to produce a urine output of 200–300 mL/hour, and alkalanization of urine is recommended to prevent acute renal failure. Compartment syndromes warrant emergent consultation of orthopedic colleagues to perform fasciotomies.

Pariser et al. recently reported on a broad population-based sample of 1,016,074 patients undergoing major urological surgeries (prostatectomy, radical nephrectomy, partial nephrectomy, and radical cystectomy) in the largest study to date investigating risk factors for development of RM. This study revealed a 0.1% (870 patients) overall incidence of RM. Patients who underwent radical prostatectomy were least likely to experience postoperative RM; patients who underwent radical/partial nephrectomy and radical cystectomy had odds ratios of 2.66 and 3.69 (p values < 0.001), respectively, of developing RM when compared to radical prostatectomy patients. Independent risk factors for RM included males, younger patients, diabetes mellitus, obesity, preexisting chronic kidney disease, and perioperative bleeding. Minimally invasive surgery was not associated with RM. Operative times were not available for analysis in this national patient sample. Length of stay and total charges were significantly greater for the RM cohort. Furthermore, 66.3% of patients with RM developed acute kidney injury and experienced a 6.4% inpatient mortality rate. In another large, population-based study, Gelpi-Hammerschmidt et al. analyzed the rates of RM following open, laparoscopic, and robotic extirpative renal surgery. The overall incidence rate of RM was exceedingly low at 0.001%; the robotic approach was associated with a greater than twofold higher risk of developing RM compared to laparoscopic surgery. Additional significant risk factors for RM included obesity, male gender, significant medical comorbidities, and operative time greater than 5 hours. Patients who experienced postoperative RM were more likely to suffer from other nonfatal complications as well as endure twice lengthier hospital stays. Deane et al. measured mean pressures exerted on patients’ skin during lateral decubitus positioning with different degrees of table flexion, kidney rest position, and operating table surfaces. Male gender (irrespective of BMI), BMI >25, table flexion (half flexion and full flexion compared to flat position), and kidney rest elevation (compared to nonelevation) were associated with higher interface pressures. Supplementary padding of the operating table with egg crate pad did not prove to significantly decrease interface pressures, while the addition of gel padding significantly increased the mean skin interface pressures by 1.61 mm Hg; thus, the authors concluded it is unnecessary to place extra protective material over the normal operating table mattress during renal surgery.

The prevalence of venous thromboembolism (VTE) events following robotic pelvic surgery has been described in the literature. In a recent multicenter analysis of a prospectively maintained LAPPRO (Laparoscopic Prostatectomy Robot Open) database, Tyritzis et al. reported on the occurrence of VTE (i.e., deep venous thrombosis and/or pulmonary embolism) in their cohort of 3544 patients undergoing open radical prostatectomy (ORP) and RARP. Their results reveal an overall incidence of VTE in 18 cases (2.2%) in the ORP cohort and in 16 cases (0.6%) in the RARP group. Importantly, a significant eightfold increased risk of development of VTE was reported when lymph node dissection (LND) was performed. Overall, ORP was associated with a significantly higher (more than threefold) risk of experiencing a VTE when compared to RARP; however, there was no significant difference in VTE events when comparing ORP and RARP with concomitant LND. When LND was taken into account, ORP resulted in a significant more than threefold incidence of postoperative VTE compared to RARP. Independent risk factors for development of VTE included a history of thrombotic incidents, advanced stage disease (pT4), and a Gleason score of at least eight or higher. Liu et al. reported similar overall rates of VTE following ORP (1.79%) and minimally invasive radical prostatectomy (0.82%) in their series of 5319 cases. Abel et al. performed a retrospective single institution review of 549 consecutive patients undergoing RARP and reported an overall postoperative VTE incidence of 1.8%; significant predictors for VTE development included increased operative time, higher BMI, and blood transfusion. Prophylaxis with unfractionated heparin prior to incision was not associated with significantly lower VTE rates or significantly higher bleeding episodes. Secin et al. reported an overall incidence of 0.5% (31 events) of VTE in a multi-institutional study that included 5951 patients undergoing minimally invasive radical prostatectomy (i.e., laparoscopic and RARP). Risk factors for VTE included history of thrombosis, smoking, increased operative time, reoperation, length of hospitalization, and increased prostatic volume. Prophylactic use of heparin either prior to surgery or postoperatively was not significantly associated with VTE (p = 0.7); in fact, centers utilizing heparin prophylaxis had similar rates of VTE when compared to centers not incorporating heparin prophylaxis. Preoperative prophylactic use of heparin was associated with significantly higher intraoperative estimated blood loss (p < 0.0005) as well as longer hospitalization (p < 0.0005). LND did not represent a significant risk factor for VTE in this series. Other RARP series have reported similarly low (less than 2%) incidence rates of postoperative VTE. Saily et al. reported on bleeding and VTE rates with preoperative and inpatient postoperative heparin administration, as well as a 15-day postoperative outpatient course of an oral anticoagulant (dabigatran) in 400 consecutive RARP patients; overall, one patient (0.25%) developed VTE, and nine patients (2.3%) developed significant postoperative bleeding, with eight patients requiring transfusion.

The safety and use of pharmacologic prophylaxis (PP) for prevention of VTE in robotic renal surgery are sparse in the literature. A current National Surgical Quality Improvement Program (NSQIP) database revealed an overall low incidence rate of patients developing VTE after minimally invasive partial nephrectomy (0.23%) and radical nephrectomy (0.42%); in this study, the occurrence of VTE was associated with more than a 12-fold increase in readmission rates (p = 0.001). Information regarding VTE prophylaxis was not provided in this national registry review. Recently, a large single institution retrospective review by Kara et al. compared perioperative outcomes of a robotic partial nephrectomy (RPN) cohort of 984 patients, of which 222 patients received PP (subcutaneous heparin or enoxaparin) at any time (preoperatively or postoperatively) and 762 patients who did not receive PP. The incidence rates of postoperative VTE were not significantly different, with 1.8% in the PP group compared to 2.1% in the non-PP group (p = 0.75); likewise, the rates of adverse hemorrhagic events were also comparable, occurring with a frequency of 3.1% and 5.6% in the PP and non-PP groups, respectively (p = 0.13). A majority (93.3%) of VTE episodes occurred within 1 month and after hospital discharge; thus, the authors concluded that inpatient-only VTE prophylaxis did not help to prevent VTE, and that a lengthier regimen (30 days postsurgery) of outpatient PP should be considered in patients undergoing RPN, as based on prior randomized control trials that evaluated prolonged PP for VTE events in open surgeries. At this time, the American Urologic Association recommends the use of intermittent pneumatic compression (IPC) in laparoscopic and robotic surgery as well as identification of high-risk patients who may benefit from VTE prophylaxis.