Aggressive Resection of Malignant Paraaortic and Pelvic Tumors Accompanied by Arterial Reconstruction with Synthetic Arterial Graft

Background

Advanced malignancies in the lower abdomen (eg, colorectal, urological, and gynecological neoplasms) easily invade the retroperitoneal and pelvic space and often metastasize to the paraaortic and pelvic lymph nodes (LNs), resulting in paraaortic and/or pelvic tumors (PPT) [1–4]. Even after radical surgery, local recurrence and/or LN metastasis can cause PPT formation [4,5]. We present our experience with aggressive malignant PPT resection and orthotopic replacement of the abdominal aorta and/or iliac arteries with a synthetic arterial graft (SAG), which has not been previously reported, and discuss treatment of locally invasive, metastatic, and recurrent PPTs.

Case Reports

CASE 1:

A 53-year-old woman diagnosed with T3N0M0 stage IIIC ovarian carcinosarcoma underwent neoadjuvant chemotherapy followed by non-curative unilateral resection of the appendicular organ, total omentectomy, and adjuvant chemotherapy. Metachronous recurrence of PPT occurred 1.8 years after the initial surgery. Aggressive tumor resection accompanied by arterial reconstruction with SAG and inferior vena cava (IVC) resection was then performed. An I-shaped SAG was used to replace the abdominal aorta from the lower level of the renal artery (RA) to the upper level of the inferior mesenteric artery (IMA) (Figure 2A). The IVC and left renal vein were resected, but venous reconstruction was not performed. Venous flow into the IVC was kept via developed collaterals in the pelvic space, gluteus maximus muscle, mesorectum and mesocolon, retroperitoneal space around the iliopsoas muscle, and Gerota fascia (Figure 3A–3E). These developed collaterals from the IVC flowed into the inferior and superior mesenteric veins and splenic vein (Figure 3A–3E). Venous flow of the left renal vein was kept mainly via splenorenal shunt, and other developed collaterals from the left renal vein flowed into the superior mesenteric vein and IVC (Figure 3A–3E). Congestion or flow disorder was not observed in the left kidney. Hence, venous flow from the IVC and left renal vein were well preserved by developed collaterals and splenorenal shunt from the early postoperative period. Lung and mediastinal LN metastases were detected 1.3 years later and she died 5.9 years after diagnosis.

CASE 2:

A 70-year-old woman diagnosed with T1bN1M0 stage IIIC endometrial cancer of the uterus with PPT underwent extended total hysterectomy, bilateral resection of the appendicular organs, paraaortic and pelvic lymphadenectomy, and partial resection of the IVC. A Y-shaped SAG was used to replace the aorta from the root of the IMA to the common iliac arteries (CIAs) 1 cm distal to the bifurcation bilaterally (Figure 2B). The patency of the partially resected IVC was well preserved from the early postoperative period (Figure 3F). Adjuvant chemo-therapy was administered after surgery. Mediastinal LN metastases were detected 1.6 years after surgery and she remained alive at 9.0 years after diagnosis.

CASE 3:

A 53-year-old woman diagnosed with T4bN0M0 stage IVA vaginal malignant melanoma underwent partial resection of the vaginal wall and postoperative chemotherapy. Subsequent local recurrences at the urethral orifice and vaginal wall and metastatic inguinal LN were resected. PPT was detected 2.6 years after the initial surgery and removed en bloc by extensive surgery that included partial vertebral body resection. A Y-shaped SAG was used to replace the aorta from the lower level of the RA to the CIAs distal to the bifurcation bilaterally. Adjuvant chemotherapy was administered after surgery. A solitary lung metastasis was detected 0.5 years after PPT resection and was surgically removed. She remains in good health without recurrence or metastasis at 9.4 years after diagnosis.

CASE 4:

A 48-year-old woman diagnosed with T3bN2M0 stage IIIC endometrial cancer of the uterus with PPT underwent total abdominal hysterectomy, bilateral resection of the appendicular organs, and paraaortic and pelvic lymphadenectomy. The PPT was removed in en bloc and a Y-shaped SAG was used to replace the aorta from the lower level of the RA to the CIAs distal to the bifurcation bilaterally. Graphical and surgical curability was obtained (Figure 4A, 4B). Adjuvant chemotherapy was administered after surgery. Peritoneal dissemination was detected 0.8 years after surgery and she remains alive 2.1 years after diagnosis.

CASE 5:

A 66-year-old man diagnosed with T3N2bM0 stage IIIC moderately-differentiated adenocarcinoma of the rectum underwent anterior resection. After paraaortic LN metastases were detected 1.4 years later, they were resected and chemotherapy was introduced. PPT was detected 4.0 years after surgery and aggressive resection accompanied by arterial reconstruction with SAG was performed. An I-shaped graft was used to replace the aorta from the lower level of the RA to the lower level of the IMA. Lung and mediastinal LN metastases were detected 0.3 years after PPT resection and chemotherapy was resumed. He died 4.8 years after diagnosis.

CASE 6:

A 43-year-old woman diagnosed with T3N2aM0 stage IIIB well-differentiated adenocarcinoma of the sigmoid colon underwent radical resection with lymphadenectomy. After paraaortic LN metastases were detected 0.6 years later and removed, chemotherapy was introduced. PPT was detected 4.0 years after the initial surgery and aggressive resection accompanied by arterial reconstruction with SAG and IVC resection was performed. A Y-shaped graft was used to replace the aorta from the lower level of the RA to the CIAs distal to the bifurcation bilaterally and adjuvant chemotherapy was resumed. Lung and mediastinal LN metastases were detected 0.3 years after PPT resection. She died 3.2 years after diagnosis.

CASE 7:

A 76-year-old man diagnosed with T3N0M0 stage IIA well-differentiated adenocarcinoma of the rectum underwent low anterior resection with lymphadenectomy. PPT was detected 1.7 years after surgery and aggressive resection accompanied by arterial reconstruction with SAG and left ureter re-section was performed. A Y-shaped graft was used to replace the aorta from the lower level of the RA to the CIAs distal to the bifurcation bilaterally. The ureter was reconstructed with an end-to-end anastomosis. Graphical and surgical curability was obtained (Figure 4C, 4D). Image studies by dynamic computed tomography and 18F-fluorodeoxyglucose positron emission tomography were repeated every 6 months after en bloc resection of the PPT. Peritoneal dissemination and lung metastasis were detected 2.9 years after PPT resection and chemotherapy was introduced. He died 9.2 years after diagnosis.

Discussion

Advanced malignancies in the lower abdomen can easily invade regional structures, metastasize to local and regional LNs, and disseminate throughout the intraperitoneal space [3,4]. Although intentional removal of local recurrence and extended lymphadenectomy of paraaortic and/or pelvic LNs may have oncologic therapeutic potential for some malignancies [1-5], extended lymphadenectomy is clearly contraindicated in some diseases [8,9]. Therefore, few cases of aggressive resection for malignant PPTs have been reported [10–12]. Arterial reconstruction was not performed in these cases; however, arterial bypass (ie, heterotopic replacement) via SAG has been described [11,12]. To our knowledge, our case series is the first report of aggressive PPT resection accompanied by arterial reconstruction (ie, orthotopic replacement) with SAG.

Pathological examination in our case series revealed that direct invasion of the arterial wall may not be observed in some cases, even when nervous plexuses, lymphatic ducts, and surrounding vessels are clearly invaded. In all of our cases, the PPT was removed en bloc and surgical cure was achieved (Table 2). We propose that intention to cure should be the goal of aggressive PPT resection with arterial reconstruction using SAG, as an oncological benefit is possible.

Details of our surgical procedures are shown in Table 2 and Figure 2. The short-term postoperative course in our patients was uneventful (Tables 2, 3). From a vascular perspective, the SAGs remained patent over the long term after surgery (Table 3) and long-term oncologic outcomes were satisfactory (Table 3, Figure 1), suggesting that our results are acceptable. Multidisciplinary therapy is crucial for advanced cancers [13]. Aggressive resection accompanied by arterial reconstruction with SAG may have a role in multidisciplinary treatment of malignant PPTs.

To our knowledge, this case series is the first report of aggressive malignant PPT resection accompanied by arterial reconstruction with SAG. This procedure is safe and feasible, shows curative potential, and may play a role in multidisciplinary management of malignant PPTs. Surgical indications for aggressive resection of malignant PPTs accompanied by arterial reconstruction (ie, orthotopic replacement) with SAG should be carefully decided on a case-by-case basis. This en bloc resection actually provided safe surgical margins, and tumor exposures were not pathologically observed in the cut surfaces (Table 2). Although the en bloc resection of malignant PPTs with surgical curability is ideal, extended resection accompanied by arterial reconstruction with SAG may be too invasive for patients with advanced cancer. In fact, tumor invasions into the arterial wall were not pathologically observed in 3 of 7 cases (42.9%) (Table 2). Regarding graphical and surgical curability (ie, graphical and surgical R0), intraoperative and postoperative findings were actually shown (Figures 2, 4). In all patients, graphical and surgical curability were obtained when aggressive malignant PPT resection accompanied by arterial reconstruction with SAG was performed (Table 2). Our institutional indication for aggressive malignant PPT resection accompanied by arterial reconstruction with SAG is simple, and it achieves graphical and surgical curability. Long-term survival seemed to be acceptable in our patients who received multidisciplinary therapy including aggressive malignant PPT re-section (Figure 1). If graphical and surgical curability can be obtained, aggressive resection accompanied by arterial reconstruction with SAG may play a role in multidisciplinary management of malignant PPTs.

Conclusions

We reported our experience with aggressive resection of malignant PPTs accompanied by arterial reconstruction (ie, ortho-topic replacement) with SAG. Our results suggest that this approach is safe and feasible, with satisfactory outcomes.