Robotic-assisted simple prostatectomy (RASP) is a minimally invasive surgery that removes the inner, obstructing portion of an enlarged prostate while leaving the outer capsule intact. It is designed for men with benign prostatic hyperplasia (BPH) whose prostates have grown large enough that standard office-based procedures are unlikely to work well, generally above 80 to 100 grams. Compared to the traditional open version of the same operation, the robotic approach consistently shows less blood loss, fewer complications, and a shorter hospital stay, though the core goal is the same: restoring normal urinary flow by physically removing the tissue that blocks it.
Who Is a Candidate
Simple prostatectomy, whether open or robotic, is reserved for men whose prostates are too large for transurethral procedures like TURP or laser vaporization to handle efficiently. The threshold most commonly cited in the literature is a prostate volume above 80 to 100 milliliters.1PubMed Central. Robotic Simple Prostatectomy: Why and How? In practice, the men who end up in the operating room for RASP often have prostates well above that cutoff, with median volumes in some series reaching 140 to 150 cc.2Société Internationale d’Urologie Journal. Robotic-Assisted Simple Prostatectomy—Short Term Functional and Surgical Outcomes Expert consensus on the procedure is still developing, and there are no formal guidelines dictating exactly when RASP should be chosen over laser enucleation or open surgery.3Asian Journal of Urology. A review based on expert opinions for robot-assisted simple prostatectomy for large benign prostatic hyperplasia
One counterintuitive finding is that prostate size alone does not determine how badly a man is suffering. A systematic review of RASP outcomes stratified by prostate volume found that patients with smaller prostates (under 100 cc) actually had more severe symptoms before surgery, even though their glands were smaller. After surgery, all groups ended up with only mild symptoms regardless of starting volume.4PubMed Central. A systematic review of robot-assisted simple prostatectomy outcomes by prostate volume The practical takeaway: if your symptoms are severe and your prostate is large enough to warrant a simple prostatectomy, the operation works whether your gland is 90 grams or 200 grams.
How the Surgery Is Performed
The surgeon operates through small incisions in the abdomen while seated at a console that controls robotic arms. The robot translates hand movements into precise, scaled-down motions inside the body. What distinguishes RASP from the more widely known robotic radical prostatectomy (used for prostate cancer) is that the capsule of the prostate is left in place. Only the overgrown inner tissue, the adenoma, is scooped out.
There are two main surgical approaches, and the choice between them matters for recovery. In the transvesical approach, the surgeon opens through the bladder wall to reach the prostate. In the transcapsular approach, the surgeon goes through the prostate capsule directly, bypassing the bladder. A comparative study found the transcapsular route had shorter console time (about 71 versus 91 minutes), shorter catheter duration (roughly 4 versus 7 days), and shorter hospitalization (5 versus 6 days). Major complications were also less frequent with the transcapsular technique, at about 3% versus 13%.5PubMed. Transvesical vs Transcapsular Robot-Assisted Multiport Simple Prostatectomy: A Comparative Analysis of Perioperative Outcomes The transvesical route still has a role, though, particularly when a patient also has bladder issues, like large bladder diverticula or stones, that need to be addressed during the same operation.
Single-Port Versus Multiport
Traditional robotic surgery uses multiple small incisions, each housing a separate robotic arm. Newer single-port platforms funnel all the instruments through one incision, typically at the navel. A multi-institutional study comparing 249 multiport cases to 156 single-port cases found that the single-port approach had less blood loss, shorter hospital stays, shorter catheter duration, and less opioid use after surgery. The 30-day readmission rate was strikingly different: about 11% for multiport versus 0% for single-port. New-onset urge incontinence was also less common with the single-port technique.6PubMed. Single Port Versus Multiport Robot-assisted Simple Prostatectomy: A Multi-institutional Study From the Single-port Advanced Research Consortium (SPARC) A smaller single-center study, however, found no significant differences and even a trend toward more complications in the single-port group.7PubMed. Standard Multiport vs Single-Port Robot-Assisted Simple Prostatectomy: A Single-Center Initial Experience The mixed results likely reflect experience: the single-port platform has a steeper learning curve, and outcomes improve as a surgical team’s volume grows.
An Unusual Anesthetic Option
Robotic surgery almost always requires general anesthesia because the patient is tilted steeply head-down and the abdomen is inflated with gas, both of which make breathing difficult without a ventilator. A small pilot series explored using epidural anesthesia without mechanical ventilation for single-port RASP by accessing the surgical field through the bladder with a percutaneous port, which avoids the steep tilt. All 12 cases were completed without converting to general anesthesia, and no anesthetic complications occurred.8PubMed. Transvesical Percutaneous Access Allows for Epidural Anesthesia Without Mechanical Ventilation in Single-Port Robotic Radical and Simple Prostatectomy This remains experimental and is limited to patients without obesity, lung disease, or sleep apnea, but it hints at a future where some men could avoid the risks of general anesthesia entirely.
What Recovery Looks Like
Hospital stays after RASP have been getting shorter as surgical techniques and perioperative care improve. In a national database analysis, the median stay for robotic cases was about 2 days, compared to 4 days for the open approach.9PubMed. Perioperative outcomes and cost of robotic vs open simple prostatectomy in the modern robotic era: results from the National Inpatient Sample Some centers have pushed this even further; one series reported a median stay of just 1 day, with all patients passing a voiding trial before discharge.2Société Internationale d’Urologie Journal. Robotic-Assisted Simple Prostatectomy—Short Term Functional and Surgical Outcomes
A urinary catheter stays in place for several days after surgery to allow the surgical site to heal. The exact duration depends on the technique: roughly 4 days with a transcapsular approach and closer to 7 days with a transvesical one.5PubMed. Transvesical vs Transcapsular Robot-Assisted Multiport Simple Prostatectomy: A Comparative Analysis of Perioperative Outcomes Once the catheter is removed, most men notice an immediate and dramatic improvement in urinary flow. Full recovery of continence and stabilization of symptoms typically takes several weeks, and some temporary urgency or frequency is normal during that period.
Advantages Over Open Surgery
The open simple prostatectomy was the gold standard for large BPH for decades, and it is still performed at centers without robotic platforms. The robotic version consistently outperforms it on perioperative measures. A single-center comparison found that blood loss was roughly a third of what it was with the open approach (about 250 mL versus 680 mL), and the rate of moderate-to-severe complications was about half (23% versus 45% before adjustment).10PubMed Central. Robot-assisted simple prostatectomy versus open simple prostatectomy: a single-center comparison A propensity-matched study confirmed the blood loss advantage, finding about 340 mL for robotic versus 590 mL for open.11PubMed. Robot-Assisted Versus Open Simple Prostatectomy for Benign Prostatic Hyperplasia in Large Glands: A Propensity Score-Matched Comparison of Perioperative and Short-Term Outcomes
In another institutional report, no RASP patients had a complication graded moderate or worse in the first 30 days, while 11 open patients did.12PubMed Central. Robotic assisted simple prostatectomy mitigates perioperative morbidity compared to open simple prostatectomy – a single institution report The reduced need for blood transfusions is one of the most practical benefits: rates of postoperative transfusion in the robotic group have been reported as low as 8%, versus nearly 30% for open cases.10PubMed Central. Robot-assisted simple prostatectomy versus open simple prostatectomy: a single-center comparison
How RASP Compares to Laser Enucleation
Holmium laser enucleation of the prostate (HoLEP) is the main competitor to RASP for very large glands. HoLEP is done entirely through the urethra with no abdominal incisions, which gives it inherent recovery advantages. One head-to-head study in Korea found that HoLEP patients had significantly shorter catheter times (about 2.5 versus 7 days) and shorter hospital stays (2.5 versus 7 days), with less drop in hemoglobin after surgery. Symptom improvement was comparable between the two techniques at follow-up.13Prostate International. Robotic-assisted simple prostatectomy versus holmium laser enucleation of the prostate for large benign prostatic hyperplasia: A single-center preliminary study in Korea
Another multi-center comparison offered a different angle. It measured a combined outcome called a “trifecta” that captures symptom relief, continence, and absence of complications together. The RASP group achieved that combined success at a higher rate than the HoLEP group (56% versus 33%), with the type of surgery being an independent predictor of the outcome.14PubMed Central. Robotic simple prostatectomy vs HOLEP, a ‘multi single-center’ experiences comparison The evidence, taken together, suggests that HoLEP gets patients home faster but RASP may deliver a more complete functional result in more patients. Access plays a large role in the choice, too: HoLEP requires a specialized laser and an experienced endoscopic surgeon, and RASP requires a robotic platform and a surgeon trained in that technique. Not every hospital has both options.
Sexual Function After Surgery
Many men worry that prostate surgery of any kind will harm their sexual function. Because RASP removes only the inner adenoma and preserves the capsule, the nerves responsible for erections, which run along the outside of the prostate, are generally spared. The largest study to date on this question followed 292 patients who underwent robotic transvesical simple prostatectomy with a specific mucosal-closure technique. Sexual Health Inventory scores before and after surgery were essentially unchanged (mean of about 12.8 preoperatively and 12.6 postoperatively). About 80% of men were sexually active before surgery, and the same proportion remained active afterward. Among those who stayed sexually active, roughly 95% were satisfied with their erectile function and 97% with their orgasm quality.15PubMed Central. Robot-assisted transvesical simple prostatectomy with circumferential mucosal anastomosis: long-term urinary and sexual function outcomes in a 292 patient cohort
One thing to be aware of: retrograde ejaculation is expected after any simple prostatectomy. Because the bladder neck is opened during surgery, semen tends to travel backward into the bladder rather than out through the penis during orgasm. This does not affect the sensation of orgasm or the ability to have erections, but it does affect fertility. For men who are not planning to father children, this is usually a minor tradeoff for symptom relief.
Long-Term Durability
One of the strongest arguments for simple prostatectomy in general, whether open or robotic, is that it removes the obstructing tissue entirely rather than ablating or vaporizing part of it. This makes regrowth and symptom recurrence uncommon. A medium- to long-term follow-up study found significant, sustained improvement in urinary flow (from about 11 mL/s preoperatively to 24 mL/s postoperatively) and residual urine volume (from about 367 mL down to 42 mL). All patients in that series were weaned off their BPH medications, and none required a reoperation for recurrent symptoms.16Société Internationale d’Urologie Journal. Medium- to Long-Term Outcomes Following Robotic-Assisted Simple Prostatectomy A separate long-term analysis confirmed durable symptom relief and high rates of achieving a combined success outcome regardless of which robotic technique was used.17Therapeutic Advances in Urology. Robotic-assisted simple prostatectomy: long-term, trifecta- and pentafecta-based analysis of functional outcomes
The one long-term complication to watch for is bladder neck contracture, a narrowing of the surgically opened bladder neck as scar tissue forms. In the long-term follow-up series mentioned above, two patients developed contractures at 44 and 63 months.16Société Internationale d’Urologie Journal. Medium- to Long-Term Outcomes Following Robotic-Assisted Simple Prostatectomy Broadly, the reported rate of bladder neck contracture after robotic prostatectomy is low, in the range of 0 to 2%, compared to roughly 3 to 8% for the open approach.18European Urology Focus. Management of Bladder Neck Contracture in the Age of Robotic Prostatectomy: An Evidence-based Guide
Incidental Prostate Cancer in the Specimen
Because the removed tissue is sent to a pathologist, RASP occasionally uncovers prostate cancer that was not suspected beforehand. A multi-institutional report on single-port RASP found incidental cancer in about 5% of specimens.19PubMed. Incidental prostate carcinoma after single-port robot-assisted simple prostatectomy: a multi-institutional report (SPARC) A similar rate, about 5%, was found in a second series using the same platform.20Urologic Oncology: Seminars and Original Investigations. 227 INCIDENTAL CARCINOMA AFTER SINGLE-PORT TRANSVESICAL ROBOT-ASSISTED SIMPLE PROSTATECTOMY Most of these incidental cancers are low-grade and low-volume, meaning they are unlikely to threaten the patient’s life. Still, discovering them allows for proper monitoring. This is an advantage that purely ablative techniques like laser vaporization do not share, since vaporization destroys the tissue rather than retrieving it for examination.
Cost and Access Considerations
Robotic surgery is not cheap. A national analysis of hospitalization costs found that RASP carried a higher total bill than the open approach (median around $13,500 versus $10,900), even though patients went home sooner. The robotic platform itself added roughly $6,200 to the cost, while each additional day in the hospital added about $1,700. The math means a robotic patient would need to stay 3 to 4 fewer days than an open patient just to break even on the robot’s added expense.9PubMed. Perioperative outcomes and cost of robotic vs open simple prostatectomy in the modern robotic era: results from the National Inpatient Sample For patients who value faster return to normal life and lower complication risk, the premium may feel worthwhile. For healthcare systems evaluating the population-level economics, the picture is more nuanced.
Access is the other practical barrier. Not every hospital has a robotic surgical system, and among those that do, not all have a urologist with sufficient experience in RASP. This matters because the procedure has a real learning curve.
The Surgeon’s Learning Curve
Even for surgeons already comfortable with robotic surgery for other procedures, RASP is a distinct operation that requires its own period of skill development. A study of experienced robotic surgeons estimated that blood loss and tissue removal efficiency improved most sharply over the first 10 to 12 cases, at which point the curve flattened.21Journal of Endourology. Determining the Learning Curve for Robot-Assisted Simple Prostatectomy in Surgeons Familiar with Robotic Surgery For the newer single-port platform, the learning curve is steeper. A risk-adjusted analysis identified a learning phase spanning roughly the first 33 cases, a proficiency phase from case 34 to 73, and a consolidation phase beyond case 75.22PubMed Central. Learning curve of single-port robot-assisted simple prostatectomy: a risk-adjusted CUSUM analysis
If you are considering RASP, asking your surgeon how many they have performed is a reasonable and important question. The difference in outcomes between a surgeon’s early cases and their mature technique can be substantial, particularly in blood loss and complication rates. A surgeon who has done 50 or more cases on their platform of choice is well past the steepest part of the curve and likely delivering outcomes consistent with the published literature.
Patients Who Had Prior Procedures
Some men arrive at RASP after less invasive treatments have failed or provided only temporary relief. One scenario studied in the literature involves patients who previously underwent prostatic artery embolization (PAE), an interventional radiology procedure that shrinks the prostate by cutting off part of its blood supply. A case series of men who had RASP after PAE found substantial improvements in symptom scores, urinary flow rates (from about 8 mL/s to 26 mL/s), and residual urine volumes after surgery.23Prostate International. Robotic-assisted simple prostatectomy after prostatic arterial embolization for large benign prostate hyperplasia: Initial experience The concern with operating after PAE is that the altered blood supply and inflammation could make the robotic dissection more difficult, but in this initial experience, the procedure was feasible and effective.
Men who have had prior TURP, laser procedures, or other transurethral surgeries can also be candidates for RASP if their prostates remain large enough. The altered anatomy from prior surgery adds complexity, which is another reason surgeon experience matters. The prostate tissue that was previously treated may have scarring or changes in texture that make enucleation more challenging, but an experienced robotic surgeon can work through these. If you have had a previous prostate procedure that failed to provide lasting relief and your gland is still large, RASP remains a viable option worth discussing with a urologist who specializes in it.