Robotic Assisted Laparoscopic Splenic Artery Aneurysm Resection

Summary

Splenic artery aneurysms (SAA) are recognized as the most common type of visceral artery aneurysms, comprising approximately 60% of such cases. Historically, the management of SAA has included open surgical, endovascular, or non-operative management. This paper describes a robotic-assisted laparoscopic surgical technique for splenic artery aneurysm resection.

Abstract

Splenic artery aneurysms (SAA) are the most common visceral aneurysm and may develop significant risk for rupture and life-threatening complications when more than 3 cm, in pregnancy, or if resembling pseudoaneurysms. Traditional treatment options of open surgical repair and endovascular repair have been extensively studied, but the role of robotic-assisted laparoscopic surgery in definitively managing SAA is emerging as a promising minimally invasive alternative in select pathology. This case aims to present the technical details, challenges, and outcomes of an SAA in a young woman treated with robotic-assisted laparoscopic resection, highlighting the feasibility and efficacy of this approach. A 38-year-old woman with no significant past medical history was incidentally found to have a distal third splenic artery aneurysm measuring 2.2 cm in diameter and was referred to a vascular surgery clinic for further evaluation. Although she was not pregnant at the time, she was undergoing fertility treatments with plans for assisted pregnancy. She requested definitive aneurysm treatment, wished to avoid multiple interventions, and intended to become pregnant via IVF within the coming year, making repeated axial imaging unsuitable for follow-up. Imaging evaluation revealed the aneurysm sac contained one prominent feeding artery and two highly tortuous draining branches. After providing informed consent, the patient underwent successful robotic-assisted laparoscopic excision of the splenic artery aneurysm. Robotic-assisted laparoscopic surgery represents a valuable approach for the definitive management of distal splenic artery aneurysms or aneurysms involving highly tortuous vessels, conditions historically requiring open surgical ligation, resection, or vascular reconstruction. This paper illustrates how challenging aneurysms can be precisely visualized, dissected, and managed using robotic-assisted laparoscopy with the DaVinci surgical system, highlighting key minimally invasive techniques for optimal exposure and vascular control in splenic artery aneurysm repair.

Introduction

Splenic artery aneurysms (SAA) are recognized as the most common type of visceral artery aneurysms (VAAs), comprising approximately 60% of such cases¹. These aneurysms can carry a significant risk of rupture when meeting size criteria (more than 3 cm) or in pregnancy with an increased plasma volume and cardiac output, leading to potentially life-threatening hemorrhage². Historically, the management of SAA has included open surgical repair and conservative management (non-operative management for patients not meeting size criteria, pseudoaneurysm morphology, or not young fertile women)^3,4. Over the past decade, endovascular (EV) approaches have been increasingly utilized due to their less invasive nature and favorable short-term outcomes compared to open repair⁵.

Recent studies comparing endovascular and open-surgical approaches for SAA management have shown promising results for endovascular techniques. Endovascular repair is associated with lower complication rates, shorter hospital stays, and reduced resource utilization compared to open surgery^5,6. A meta-analysis found significantly lower overall mortality rates with endovascular repair⁷. However, randomized trials showed similar splenectomy rates and technical options for both approaches, with laparoscopy offering shorter procedures and lower morbidity⁸. While endovascular repair demonstrates advantages in perioperative outcomes⁹, the need for reintervention after endovascular repair remains a concern, with freedom from reintervention at 3 years postoperatively reported as 82.4%, mostly due to sac reperfusion⁶. These findings suggest that endovascular repair may be a preferred initial strategy for SAA management, but further comparative studies are needed.

Robotic-assisted and laparoscopic surgery have emerged as viable minimally invasive options for treating SAA. These approaches demonstrate comparable operative times, low open conversion rates, and reduced morbidity compared to open surgery². Robotic-assisted laparoscopic surgery allows for complex procedures, including aneurysm excision with arterial reconstruction, and shows promising mid-term results^4,9. A randomized study comparing open and laparoscopic SAA management found that laparoscopy permitted multiple technical options without increasing splenectomy rates while reducing postoperative complications and hospital stay⁸. However, laparoscopic arterial anastomoses showed poor long-term results. Complex vascular reconstructions have now been demonstrated in the transplant literature and by international vascular surgeons on the DaVinci Xi platform, emphasizing the increased dexterity and wristed instrument of the robotic platform, a prior limitation of laparoscopic surgery¹⁰. Both robotic and laparoscopic approaches result in shorter hospital stays and lower overall morbidity rates compared to open surgery^2,8. These minimally invasive techniques represent important advancements in SAA treatment, offering tailored options for patients, particularly those at high surgical risk.

Despite these advancements, the rarity of SAA has precluded the conduct of large randomized controlled trials, resulting in a reliance on case reports and series to inform clinical practice⁴. Existing literature indicates that while endovascular approaches may offer superior short-term results, they also require more reinterventions compared to open surgery, which is associated with fewer late complications⁵. Moreover, splenic infarction and pancreatitis are noted as common complications in minimally invasive approaches¹¹.

By examining this case, we aim to provide further insights into the technical details of robotic-assisted laparoscopic surgery for SAA by providing a comprehensive protocol. This paper and accompanying video will serve as a template to instruct robotic instrument selection, port placement and DaVinci Xi robot docking, gastropexy for visualization, exposure of a distal splenic artery aneurysm, vascular control of feeding and draining arteries, and ligation of a splenic artery aneurysm.

CASE PRESENTATION:

A 38-year-old Caucasian female presented to the vascular surgery clinic for evaluation after an incidental finding of a distal splenic artery aneurysm found on an MRI performed for evaluation of adrenal glands. She had a surgical history of prior C-sections and no other significant medical history. Her home medications included Aspirin 81 mg daily, folic acid, fish oil, and prenatal vitamins. She was undergoing fertility treatments with plans for in vitro fertilization this year. She drank alcohol socially and denied tobacco and drug use. In regard to the SAA, she was asymptomatic, and on review of her imaging, there were no other visceral aneurysms identified. The physical exam was unremarkable other than a well-healed Pfannenstiel incision.

Diagnosis, assessment, and plan
The decision was made to obtain new contrasted CT imaging to investigate the anatomy of the splenic artery aneurysm and allow for surgical planning. CTA Abdomen/pelvis showed a 2.2 cm x 1.9 cm distal 1/3 splenic artery aneurysm with two draining branches and one feeding artery. All arteries showed high levels of tortuosity (Figure 1A-B). The patient was counseled about the recommendation for repair, given her plan for the upcoming pregnancy, which would place her at increased risk for an aneurysm rupture. She agreed to surgical repair but requested to avoid the endovascular approach as she did not want to have increased exposure to radiation in her operation and follow-up course, given her fertility treatments and plans for upcoming assisted pregnancy. The options of open surgery through midline laparotomy with a plan for splenic artery aneurysm repair versus robotic-assisted laparoscopic splenic artery aneurysm resection and possible repair were described to her. She opted for the minimally invasive robotic-assisted approach. Risks and consequences, including but not limited to perioperative bleeding, perioperative pancreatitis, splenic artery occlusion and infarct of the spleen, secondary infections, the need for blood transfusions, splenectomy, and the need for post-splenectomy vaccines, were discussed with the patient in detail. All questions were answered, and she wished to proceed.

Protocol

The patient provided informed consent to the report of her case details and imaging studies. This study was conducted, and the protocol was written in accordance with the ethical guidelines and regulations of the Houston Methodist Hospital Ethics Committee.

1. Pre-operative planning

1. Obtain complete written informed consent from the patient. Consent should discuss the following: Robotic-assisted laparoscopic splenic artery aneurysm ligation and/or resection, splenic artery reconstruction, conversion to open splenic artery aneurysm resection (laparotomy), splenectomy (total or partial), pancreatic injury repair, bowel injury repair, blood transfusion, placement of surgical drains, post-splenectomy vaccines.
2. Use a proper timeout procedure to identify the correct patient, the correct procedure, and the operating surgeon.
3. Take the patient to the operating room, place them in a supine position, and administer general endotracheal anesthesia. Secure the patient using a bean bag or gel pads.
4. Prepare the surgical site with an antiseptic solution (2% chlorhexidine or betadine solution) and drape in a standard sterile fashion (with the patient exposed from pubic symphysis to xiphoid process). Give 2 g Ancef intravenously prior to induction for antibiotic prophylaxis.

2. Laparoscopic and robotic entry

1. Mark the four robotic port sites at 8 cm intervals in a horizontal line approximately 14 cm inferior to the xiphoid process. Make a horizontal 8 mm incision in the skin on the left paramedian region and use an optical trocar to gain access to the peritoneal cavity using the standard technique (Figure 2).
2. Establish pneumoperitoneum. Under laparoscopic visualization,place three additional 8 mm ports in the port sites marked, and place an extra 5 mm port in the right subcostal region for a left liver retractor using standard technique and fix it to the bed. Tilt the bed in reverse Trendelenburg (15°-20°) to facilitate better visualization of the upper abdomen.
3. Place a 12 mm assistant port inferiorly and in between the supraumbilical and left paramedian port (Figure 2).
4. Remove the 12 mm port and use a PMI device and 0 Vicryl suture to pre-close the fascial defect by placing a suture through the abdominal fascia, but do not tie it at this point. Then, reinsert the 12 mm assistant port.

3. Robotic docking and setup

1. Dock the DaVinci Xi robot from the patient's right side using the standard technique. Align the boom arm parallel to the patient's midline. Press the Port Assignment button on the touchscreen monitor and select Four-arm Setup. Ensure the camera boom is centered over the planned camera port (port #2) using the laser-assisted crosshairs to assist.
2. Attach the robotic arms to the ports: Robot arm 1 (left lateral port) to fenestrated bipolar grasper, arm 2 (midline port) to the camera, arm 3 (right lateral port) to the vessel sealer, arm 4 (far right lateral port) to Cadiere forceps.
3. Perform exposure of the splenic artery as described below.
   1. Using a bipolar fenestrated grasper, a vessel sealer, and Cadiere forceps, perform dissection along the greater curvature of the stomach to divide the anterior leaflet of the greater omentum and enter the lesser sac. Perform further dissection superiorly and inferiorly, superiorly up to the takeoff of the short gastric arteries, which should be kept intact, and inferiorly to the inferior portion of the greater curvature.
   2. Use tacking sutures with 2-0 Vicryl V-Loc sutures to tack up the stomach to the anterior abdominal wall.
   3. After opening the lesser sac, the posterior gastric fat pad was visualized. A pulsating mass was seen; use it as a landmark for where to open the fat pad the visualize the splenic artery. Identify the splenic artery at the superior border of the pancreas (Figure 1D). Perform dissection with a fenestrated bipolar grasper and monopolar hook around the proximal splenic artery and obtain proximal control.

4. Vascular control and ligation

1. Control the artery with a vessel loop and a 1 cm red rubber catheter to make a modified Rumel technique. Clip the vessel loops to secure them in place. Next, carry out dissection around the inflow artery and the outflow arteries of the aneurysm using a fenestrated grasper and hook electrocautery.
2. Encircle the arterial inflow and outflow branches and obtain vascular control with vessel loops. Occlude the feeding artery and check Firefly fluorescence for adequate perfusion of the spleen.
3. Perform careful inspection of the distal outflow branches. This showed three branches, two of which were large, and one was small. Both the large branches were extremely thin walled, which would then be a risk for anastomotic suture dehiscence and breakdown with pseudoaneurysm formation and, hence, not worth the risk of primary repair. Therefore, the decision was made to ligate the artery and resect the aneurysm.
4. Clip all the arterial inflow and outflow branches and divide them with the vessel sealer using the standard technique (Figure 1E).

5. Removal of aneurysm specimen, hemostasis, and closure

1. Dissect the aneurysm from the retroperitoneum with a hook electrocautery using standard technique. Maintain hemostasis with a fenestrated bipolar grasper. Excise the aneurysm completely and place in an Endo Catch retrieval bag (Figure 1C).
2. Irrigate the area with normal saline till the returning fluid is clear. Secure hemostasis. Remove the stray sutures on the stomach for the gastropexy. Remove the liver retractor from the right subcostal port.
3. Remove the ports under visualization. Secure hemostasis to the port sites. Remove the Endo Catch bag with the specimen from the 12 mm assist port. Discontinue pneumoperitoneum completely.
4. Tie down the Vicryl sutures previously placed in the fascia at the 12 mm port site. Irrigate all the incisions with normal saline and close the remaining 8 mm and 5 mm port sites with 3-0 PDS deep dermal simple interrupted suture. Extubate the patient and move to the recovery room.

6. Post-operative Care

1. For pain control, use the following regimen post-operatively. Administer Tylenol 650 mg per oral (PO) every 6 h, methocarbamol 500 mg PO 3x daily, gabapentin 200 mg PO 2x daily, lidocaine 4% patch placed on abdomen daily, and tramadol 50 mg PO every 6 h as needed for severe pain (pain score 7-10).
2. Administer intravenous (IV) Zofran 4 mg as needed every 8 h and IV promethazine 6.25 mg every 6 h as needed for nausea.
3. Anticipate a hospital stay of 2-3 days. Here, the patient stayed a total of 4 days before discharging home due to some persistent post-operative nausea that improved with administration of 4 mg IV Zofran and 6.25 mg IV promethazine.
4. Ask the patient to follow up at the clinic at 1 month post-operatively. Perform a physical examination and abdominal ultrasound exam, with the ultrasound confirming the proximal and mid-splenic artery without residual aneurysm or formation of new pseudoaneurysm. Perform a repeat splenic ultrasound at 7 months after surgery with normal arterial and venous waveforms confirming adequate perfusion to the spleen.

Results

The procedure was carried out by a vascular surgeon trained in robotic surgery. The surgical team consisted of the Attending surgeon, a Circulator nurse, a Scrub nurse, and a Surgical Resident. The total operative time was 233 min. The estimated blood loss was 20 mL. There were no intraoperative complications or transfusions. The patient was transferred from the recovery room to the surgical floor with normal range hemodynamics and controlled pain.

From a technical perspective, these results validate the operative workflow described, including port placement, gastropexy for visualization, precise vascular dissection, and ligation techniques. The successful identification and preservation of short gastric arterial collaterals, verified intraoperatively with FireFly fluorescence imaging, ensured adequate splenic perfusion post-ligation, reducing the risk of splenic infarction or the need for arterial reconstruction. Additionally, the absence of pseudoaneurysm formation or need for reintervention at the 1-month and 7-month ultrasound follow-ups provides supporting evidence for the durability of this surgical technique (Figure 3). This was determined from the normal arterial and venous waveforms seen on the splenic ultrasound showing adequate perfusion of the spleen, and the healthy appearing proximal and mid segment splenic artery near the operative site where the ligation took place.

Post-operative care
On the postoperative day (POD) 0, the pain was well controlled, but the patient developed nausea and vomiting. The patient remained on nothing per oral (NPO) overnight after surgery and received IV 4mg Zofran and 6.25mg Phenergan. On POD 1 the patient required IV pain medication but was comfortable with mild nausea that improved with additional Zofran and Phenergan. On POD 2, the patient tolerated a soft diet, walked 200 feet in the hospital unit, and received prophylactic splenectomy vaccines. On POD 3, the patient no longer required IV pain medication was tolerating a full diet and had regular bowel function. The patient was discharged home early morning on POD 4 in good condition. The patient was seen in the clinic at 2 months follow-up. A physical examination and abdominal ultrasound exam were performed, with the ultrasound confirming the patent proximal and mid-splenic artery without an aneurysm. The patient had returned to daily activities without difficulty and had no signs of surgical site complications. The patient had a repeat splenic ultrasound 8 months after surgery with normal arterial and venous waveforms.

Figure 1: Pre-operative and intra-operative imaging of splenic artery aneurysm. (A) Computed tomography angiography (CTA) Imaging of Splenic artery aneurysm (SAA). Contrasted imaging of the mid-distal highly tortuous SAA. (B) 3D-Reconstruction of SAA. 3D reconstruction highlighting tortuous branching pattern of SAA and multiple draining branches present. (C) Excised SAA. Excised SAA on the back table at the completion of the case. (D) Robotic View of SAA. Initial dissection of the SAA prior to vascular control and ligation of SAA branches. (E) Ligation of SAA. Picture of SAA with clips applied to each branch prior to excision from the patient. Please click here to view a larger version of this figure.

Figure 2: Anatomical landmarks and port placement. Four robotic port sites at 8 cm intervals in a horizontal line approximately 14 cm inferior to the xiphoid process. A 5 mm port in the right subcostal region for a left liver retractor. A 12 mm assistant port inferiorly and in between the supraumbilical and left paramedian port. Please click here to view a larger version of this figure.

Figure 3: Post-operative splenic ultrasound. (A) The 1-month splenic artery waveforms. (B) The 1-month splenic vein waveforms. (C) The 7-month splenic artery waveforms. Both (A and C) show a low resistance and monophasic waveform with a sharp systolic upstroke. This signifies continuous forward flow through the cardiac cycle and lack of turbulent flow. (D) The 7-month splenic vein waveforms. Both (B and D) show continuous, low-velocity flow directed towards the portal vein. Please click here to view a larger version of this figure.

Discussion

Laparoscopic and robotic treatments of visceral artery aneurysms (VAA) are described in the literature^12,13,14,15. Still, they historically are limited in daily clinical practice mainly due to limited expertise amongst vascular surgeons and the facility cost of the surgical robots. In addition, endovascular repair continues to represent first-choice management in most cases¹⁶. This combination of factors makes evidence concerning the robotic-assisted laparoscopic approach for VAAs limited. Prior to 2010, there were only seven cases of robotically treated VAAs published in the literature. Between 2011 and 2019, a systematic review found only 20 patients and just 27 more between 2020 and 2024¹⁷. The use of robotic techniques in the treatment of VAAs is increasing at a rapid pace, but the only available data regarding its outcomes remains limited to case reports and case series.

Although other case reports describing similar cases already exist, this study's value lies in its detailed description of the operative technique, including a video presentation-and in its comprehensive protocol for peri-operative patient care.

One of the most important advantages of robotic assisted laparoscopic surgery (RALS) is the extremely low rate of peri-operative complications, thanks to the minimally invasive approach. Many reviews have shown significantly decreased cardiac, respiratory, thromboembolic, and infections compared to open surgery for VAAs. Moreover, the robotic-assisted approach is characterized by early recovery of oral feeding and short hospital stay¹⁷. These added benefits might counterbalance the additional cost of the robotic equipment; however, we are unable to provide a detailed cost analysis for this case.

While there are many benefits to the RALS approach, possible disadvantages are the operative time and periods of organ ischemia if performing a vascular reconstruction. There is no information based on large clinical trials concerning the operative time and ischemia times of open surgery of VAAs, but those of RALS may be slightly longer^18,19. This may be due to the learning curve and could be liable to improve in the future. However, on review of early data, such longer times did not cause significant adverse clinical outcomes. In our case, the total operative time was 233 min. This is longer than the average reported time in the 2020 review² (150 ± 87.7 min) but within one standard deviation. The presented case involved complex anatomy with an extra draining artery branch that needed to be controlled and ligated. This was also the first robotic splenic artery surgery in our institution; thus, the relatively longer operative time was needed to instruct assistants in the operating room. We were able to reduce the operative time in the following 3 cases, with the latest one consisting of aneurysm resection and arterial repair (130 min and 188 min for ligation, and 256 min for arterial reconstruction with end-to-end anastomosis).

Early data indicate satisfactory rates of intraoperative conversion to laparoscopic or open surgery (5.6%). Among VAAs, splenic artery aneurysms (SAA) appear particularly susceptible to conversion, primarily due to dense tissue adhesions that complicate vascular control; this was identified as the most frequent reason for procedural failure¹⁷. Consequently, patients with hostile abdominal anatomy may carry a higher risk of conversion, emphasizing the importance of careful patient selection to reduce this risk. Patients eligible for RALS should be informed about the possibility of conversion, similar to other minimally invasive procedures such as endovascular or laparoscopic treatments. However, robotic repair offers an advantage over endovascular approaches, as it does not carry the risk of aneurysm reperfusion and rupture, a significant limitation associated with endovascular treatment.

The robotic-assisted laparoscopic splenic artery aneurysm (SAA) resection involves several critical steps to ensure safe and effective aneurysm management. First, pneumoperitoneum is established, and the DaVinci Xi robot is docked to four abdominal ports, with an additional 12 mm assistant port for instrument exchange and a 5 mm port for liver retractor placement. After docking, the greater omentum is dissected from the greater curvature of the stomach, exposing the posterior gastric fat pad and creating access to the lesser sac. The splenic artery is identified along the superior border of the pancreas, and meticulous dissection is performed to isolate the aneurysm and its vascular branches. The inflow and outflow vessels are encircled with vessel loops for vascular control, with the option of using a modified Rumel tourniquet technique for proximal occlusion. Intraoperative FireFly fluorescence imaging is utilized to assess splenic perfusion through the short gastric arteries before proceeding with arterial ligation and aneurysm excision. The aneurysm is resected, the surgical field is irrigated, and hemostasis is secured. Finally, ports are removed under direct visualization, the fascial defects are closed, and the patient is carefully monitored postoperatively for early recovery and return to normal function.

Recommended modifications to the technique are the use of robotic bulldog clamps (Klein Surgical) for vascular control which decreases operating time compared to vessel loop and Rumel tourniquet⁴. Another modification would be performing an end-to-end anastomosis to reconstruct the splenic artery in patients with questionable collateral blood supply to the spleen, and that would not tolerate splenectomy/splenic embolization.

A future application of this technique would be the expanded use in other visceral artery aneurysms (hepatic, renal, superior mesenteric, and celiac artery aneurysms). Other applications would be performing robotic-assisted arterial bypass and reconstruction procedures, performing hybrid endovascular-robotic techniques, and adopting these skills to perform vascular repairs for iatrogenic injuries when vascular surgeons are consulted intra-operatively.

In conclusion, RALS offers several advantages, although its applicability remains limited to specific situations. Currently, there is neither consensus nor clear evidence to guide optimal patient selection, and defined inclusion and exclusion criteria for RALS candidates are still lacking. In cases of splenic artery aneurysm (SAA), RALS might be preferred over endovascular approaches for aneurysms located at the splenic hilum, particularly when embolization or endograft placement risks sacrificing collateral vessels, potentially leading to splenic infarction or post-embolization syndrome. Additionally, younger patients at higher risk for long-term reintervention after endovascular treatment could also benefit from robotic-assisted procedures.

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
2-0 Vicryl V-Lock Suture		VLOCM0115
8m endoscope plus, 30 degree	Intuitive Surgical	470057
8mm blunt obturator	Intuitive Surgical	470008
8mm cannula	Intuitive Surgical	470002
BD Bard All-Purpose Red Rubber Unisex, 16FR, Straight	Bard	277716
Bipolar energy instrument cord	Intuitive Surgical	470384
Cadiere Forceps	Intuitive Surgical	471049
Da Vinci Xi surgical robot	Intuitive Surgical	380662-21	Robotic assisted surgical platform
Endo catch specimen retrieval bag	Medtronic	173050G
Fenestrated Bipolar Forceps	Intuitive Surgical	471205
Hot Shears (Monopolar Curved Scissors)	Intuitive Surgical	470179
Laparoscopic 5mm x 100mm Trocar	Ethicon	2B12LT
Laparoscopic Suction Irrigator	Pilling	728145
Large Clip Applier	Intuitive Surgical	470230
Large SutureCut Needle Driver	Intuitive Surgical	471296
Monopolar energy instrument cord	Intuitive Surgical	470383
Permanent Monopolar Cautery Hook	Intuitive Surgical	470183
Snake Liver Retractor 5mm 80mm End	Artisan Medical Devices	SNK-100
Tip-Up Fenestrated Grasper	Intuitive Surgical	470347
Vessel Loop McKesson Mini Red Silicone Radiopaque	McKesson	487858
Vessel Sealer Extend	Intuitive Surgical	480422