Laparoscopic-assisted resection of a large retroperitoneal tumor.

BACKGROUND: Retroperitoneal tumors have traditionally been excised using standard open techniques. When preparing the manuscript we knew of only 1 report, in Japanese, describing the excision of 2 retroperitoneal neurofibromas using a minimally invasive technique. The feasibility of the technique was tested in the removal of a large retroperitoneal neurofibroma.
METHODS: Laparoscopic-assisted resection of a large retroperitoneal tumor was offered to a 37-year-old female with a 12 x 10 x 9-cm neurofibroma located inferior to the left kidney. The patient was placed on a beanbag in a right lateral decubitus position. Three 5-mm ports were used, and the tumor was mobilized followed by placement of a hand port for completion of dissection and removal of the tumor.
RESULTS: The tumor was successfully removed in about 3 hours, and blood loss was <100 cc. The patient developed urinary and bowel dysfunction probably secondary to the effect of the dissection and removal of the tumor on the nearby sacral plexus.
CONCLUSIONS: We believe that laparoscopy is a feasible and appropriate technique available to general and laparoscopic surgeons in the management of retroperitoneal tumors, providing excellent visualization and adequate access for proper dissection through small incisions.

INTRODUCTION

Retroperitoneal tumors have traditionally been excised using standard open techniques. Only 1 report that we know of, in Japanese, describes the excision of 2 retroperitoneal neurofibromas using a minimally invasive technique.l In this article we will describe laparoscopic-assisted excision of a large retroperitoneal neurofibroma measuring 12x10x9 cm, emphasizing the feasibility of minimally invasive surgery as a viable tool in the armamentarium of the general or laparoscopic surgeon in the management of retroperitoneal tumors.

CASE REPORT

A 37-year-old African American female with a prior history of neurofibromatosis was referred to neurosurgery with complaints of a 1-year history of left flank pain and heaviness. The pain was described as dull, persistent, and aggravated by physical activity. Over the course of 2 months preceding her presentation, the patient developed numbness down her legs, more so on the left side, consistent with radiculopathy. A physical examination revealed the presence of a large palpable mass in the left flank below the kidney level with some sensory impairment down the left leg without evidence of motor dysfunction. Given her past history including prior resections of multiple neurofibromas at different locations, the patient underwent appropriate imaging of the entire spine. Magnetic resonance imaging showed a large enhanced mass with a swirl-like inhomogeneous appearance involving T2 lengthening, displacing the left psoas muscle medially and ventrally. The bony alignment appeared normal. No abnormal signal was noted within the cord or spinal canal. The disc spaces appeared maintained (. Also, a similar 2-cm lesion was present in the area of the thoracic spine. After consultation with neurosurgery, the patient was referred to general surgery for possible resection of the flank lesion using minimally invasive surgery.

MRI scan showing a large enhanced mass with a swirl-like inhomogeneous appearance involving T2 lengthening (L mark), displacing the left psoas muscle medially and ventrally.

SURGICAL TECHNIQUE

The details of the procedure including all risks and benefits were explained to the patient, and informed consent was obtained. After general anesthesia, a nasogastric tube and a Foley catheter were inserted. The patient was then positioned on a beanbag in a right lateral decubitus position, with the left side up. Both upper extremities were extended anterior and cephalad to keep them away from the surgical field. Both lower extremities were mildly flexed at the hips and the knees to provide stability to the patient's position on the table. Adequate soft padding was provided to protect all body prominences. We started the procedure by inserting a Veress needle in the left subcostal area at the midclavicular line followed by CO2 insufflation to a pressure of 15 mm Hg. A 5-mm port was then inserted at the same location. With the scope in place, 2 additional 5-mm ports were inserted, 1 lateral to the umbilicus, and the other in the left lower quadrant to provide access from all angles (. Inspection revealed a prominence lateral to the descending colon. Using laparoscopic Endoshears, the white line of Toldt was taken down from the pelvic brim all the way to the lienocolic ligament. The descending colon was pushed to the midline, exposing the tumor (. A plain of dissection was entered tangential to the tumor itself to avoid possible injury to any of the retroperitoneal structures. With alternation of type (0 versus 30 degrees) and location of the scope in relation to the working ports, the entire tumor was mobilized under direct vision except for the medial-most aspect close to the vertebral column. The large size and weight of the tumor precluded proper visualization. Since we had to make an incision for the delivery of the tumor, we decided to place a hand port in the left flank over the tumor itself. A 6-cm muscle-cutting incision was fashioned all the way into the peritoneal cavity. A hand port was placed through which a gentle blunt dissection and retraction was performed until the tumor was completely detached. We had to extend the incision another 4 cm to be able to deliver the tumor to the outside. The incision was then closed in the usual manner. The operating time was approximately 3 hours, and the blood loss was less than 100 mL.

The patient is placed in the left lateral decubitus position during surgery. Note the port sites arranged around the small flank incision (hand port).

The excised neurofibroma (12x10x9 cm).

RESULTS

Postoperatively, the patient had the appropriate level of pain from the muscle-cutting incision, but also developed bowel and bladder dysfunction manifested by prolonged ileus and urinary retention. She required a hospital stay of 5 days for her symptoms to resolve. Prior to discharge, the patient was tolerating an oral diet with normal bladder and bowel function.

DISCUSSION

Neurofibromas are distinct characteristics of neurofibromatosis type 1 (NF l). They are normally benign and tend to appear in a variety of anatomical regions, ranging from rare locations such as lacrimal and thyroid glands to their more common cutaneous presentation.[2-6] NF 1 is an autosomal dominant condition with a frequency of 1 in 4000 caused by mutations of the NF l gene located at chromosome 17, 19, 22q[7]. Neurofibromas can present in 3 forms: cutaneous, subcutaneous, and plexiform. Plexiform neurofibromas, typically larger and associated with deeply placed nerves, extend into contiguous tissues and may cause serious functional impairment. They are found in many cases of NF 1, of which a small percentage become malignant.[8] The involved nerve is focally swollen, but the entire nerve segment is infiltrated, rendering surgical excision difficult. When involving a noncutaneous location, neurofibromas are more likely to cause weakness and sensory symptoms.

Because our patient was symptomatic, surgical excision was the only reasonable option for management. To minimize the surgical trauma, a laparoscopic-assisted approach was contemplated, given all the known advantages of minimally invasive surgery. However, the patient did require a prolonged hospital stay of 5 days, secondary to postoperative bowel and bladder dysfunction. Although both can be partially attributed to pain from the muscle-cutting incision, it is possible that the attachment of the tumor to, and the surgical manipulation near the parasympathetic plexus were contributing factors. Certainly, this event would not have been avoided with an open technique.

CONCLUSION

We believe that laparoscopy is a feasible and appropriate technique available to general and laparoscopic surgeons in the management of retroperitoneal tumors, providing excellent visualization and adequate access for proper dissection through small incisions.