Robotic retroperitoneal tumor resection: a video vignette

Abstract

The utility of robotic platform remains relatively unexplored in the context of retroperitoneal tumors. The location and complexity of neurovascular anatomy pose additional challenges for surgical planning. Herein, we present the case of a 56-year-old male with a 9 × 7-cm retroperitoneal tumor located within the right iliopsoas muscle, without intraforaminal extent. The surgery was performed using the da Vinci Xi Surgical System (Intuitive Surgical, Inc.). The patient was placed in the left lateral position. Intraoperative and postoperative recovery was uneventful. A transient sensory deficit was noted in the right lower limb, which gradually resolved completely. The patient was discharged on postoperative day 4. Histopathology report confirmed a schwannoma with negative margins. At 1-year follow-up, the patient is doing well with no evidence of disease recurrence. Robotic resection of retroperitoneal tumors appears to be a feasible and safe approach. Proper planning and execution are essential for the successful completion of the surgery and achieving excellent outcomes.

INTRODUCTION

Retroperitoneal tumors (RPTs) are a rare group of soft tissue tumors that occur in the retroperitoneum. RPTs are classified as primary or secondary. While primary RPTs are defined as those originating from retroperitoneal soft tissues or organs, secondary tumors refer to metastatic lesions or lymph node masses that develop in the retroperitoneal space but do not originate from the retroperitoneum [1]. RPTs originate from fat, muscle, lymphatics, nerve, or residual embryonic tissue [2,3].

Primary RPTs are further divided into benign and malignant. The majority of RPTs are malignant, accounting for approximately 70% to 80% of primary RPTs. Benign RPTs account for approximately 20% of all RPTs [2]. Although schwannoma is the most common benign neurogenic tumor in the retroperitoneum, retroperitoneal schwannoma is extremely rare and comprises only about 4% of all RPTs.

Herein, we report a case of a 56-year-old male patient who presented with a 9 × 7-cm RPT located within the right iliopsoas muscle without intraforaminal extension, and was managed via a robotic surgical approach.

CASE

We report the case of a 56-year-old male with good performance status (Eastern Cooperative Oncology Group performance status of 0), no comorbidities, who was evaluated for vague complaints of abdominal pain. On evaluation, magnetic resonance imaging (MRI) revealed a well-circumscribed 8.6 × 4.9-cm-sized mass lesion in the right iliopsoas muscle that appeared hypointense on T1-weighted images and hyperintense on T2-weighted and STIR (short tau inversion recovery) images, with few intralesional cysts (Fig. 1). In the contrast study, there were multiple tiny non-enhancing areas, likely cystic degenerative changes with moderate enhancement of the solid component. There was no extension into the neural foramina. Whole-body positron emission tomography with contrast-enhanced computed tomography (Fig. 2) corroborated the MRI findings and ruled out distant metastatic disease. After discussion in a multidisciplinary tumor board, the patient was planned for robotic RPT resection.

Fig. 1.

Magnetic resonance imaging: 9 × 7 cm mass lesion in the right psoas muscle (arrow) that appears hyperintense on T2-weighted and STIR images, and a few intralesional cysts with a solid component; no interspinous extension noted.

Fig. 2.

Whole-body contrast-enhanced computed tomography (A) and positron emission tomography (B). A well-circumscribed, heterogeneous 9 × 7 cm lesion (arrows) within the right iliopsoas muscle, extending to the right paravertebral space at the level of the L4 vertebra.

The surgery was performed using the da Vinci Xi Surgical System (Intuitive Surgical, Inc.). The patient was placed in the left lateral position. The patient cart of the robot was placed on the patient's right. Four standard 8-mm robotic ports were inserted in a straight line along the right midclavicular line, 8 cm apart (Fig. 3). The camera was docked in the third robotic arm. Assistant port (8 mm) was placed approximately 4 to 5 cm above the umbilicus in the midline, which later served as a utility incision for specimen retrieval.

Fig. 3.

Intraoperative image demonstrating port placement. R1, arm 1; R2, arm 2; R3 (C), arm 3 (camera); R4, arm 4; A, assistant port.

Supplementary Video 1 demonstrates the surgical procedure titled “robotic retroperitoneal tumor resection.” The console time was 120 minutes, with minimal blood loss of 200 mL. The patient was extubated on the table and started on an oral diet the same day. Postoperative recovery was uneventful. There was a transient sensory deficit that gradually resolved completely. The drain was removed on postoperative day 3, and the patient was discharged. Histopathology report confirmed the diagnosis of benign schwannoma, and the margins were negative. At 1-year follow-up, the patient is doing well with no evidence of disease recurrence. Fig. 4 depicts a postoperative picture of the specimen.

Fig. 4.

Postoperative picture of specimen.

DISCUSSION

Surgical resection with negative margins is the standard treatment for RPTs. Traditionally, RPTs were managed by open surgery, and the conventional open approach has still remained the standard way to operate upon these tumors. Despite distinct advantages, minimally invasive approaches like laparoscopy and robotic surgery have faced more difficulties and challenges in making their place in the treatment of RPTs. The utility of the robotic platform is relatively unexplored in the case of retroperitoneal tumors. The location and complex neurovascular anatomy of the RPTs further add to the challenge. The benefit of robotic over laparoscopic platform is the three-dimensional view, magnified imaging, and the endo-wrist technology of the robotic instruments that offers seven degrees of freedom. These benefits of robotic platforms are slowly being appreciated, resulting in the adoption of robotics for the management of RPTs. There is a flux of literature supporting and demonstrating the utility of robotics for RPT surgery in terms of short-term perioperative outcomes like blood loss, postoperative pain, time to oral intake, and hospital stay [4–6].

The meticulous preoperative surgical planning is essential to overcome challenges and successful completion of surgery. While either transperitoneal or retroperitoneal approach can be used, the literature is sparse comparing the advantages and disadvantages of one over the other. The transperitoneal approach provides a large working space for dissection and more visualization; however, it requires mobilization of intraperitoneal organs. The retroperitoneal approach has a smaller working space with less visualization but does not require mobilization of intraperitoneal organs [5,7–9]. The robotic resection of RPT is subject to judicious case selection. The literature has reported a 17% rate of conversion to open surgery. According to this study, a high rate of successful completion of robotic surgery was associated with maximum tumor diameter <64 mm, without invasion to adjacent structures and which do not entail en-bloc multivisceral resection [3].

The potential complications include injury to surrounding organs and structures including bleeding, injury to the ureter, injury to nerves like the genitofemoral, ilioinguinal nerve, and injury to the psoas major muscle. As the tumor in our case had intramuscular extent in the psoas muscle, a few fibers of the psoas muscle had to be sacrificed in order to obtain clear margins. However, there was no postoperative motor deficit. The femoral branch of the genitofemoral nerve was seen traversing through the tumor and hence had to be transected. The patient experienced a transient sensory deficit of the upper anterior thigh, which spontaneously resolved completely.

Before embarking on a robotic approach for RPT, it is prudent for the surgeon to be cognizant of the complex retroperitoneal anatomy and the relationship of the tumor to surrounding complex structures, laced with adept technical skills and readiness for conversion to open surgery, if needed. There is a dearth of educational surgical videos on robotic RPT resection, thereby encouraging us to publish our work.

In conclusion, the robotic resection of retroperitoneal tumors is a feasible and safe approach. With proper planning and execution, excellent surgical outcomes can be achieved.

Supplementary materials

Supplementary materials can be found via https://doi.org/10.7602/jmis.2025.28.4.205.