- Email: [email protected]
Polytetrafluoroethylene Is a Safe and Effective Interposition Conduit for Caval Reconstruction After Resection of Primary Leiomyosarcoma of the Inferior Vena Cava
Polytetrafluoroethylene Is a Safe and Effective Interposition Conduit for Caval Reconstruction After Resection of Primary Leiomyosarcoma of the Inferior Vena Cava Aravind G. Kalluri, Ashish K. Jain, Heron E. Rodriguez, and Mark K. Eskandari, Chicago, Illinois
Background: Primary leiomyosarcoma of the inferior vena cava (IVC) is a rare soft tissue sarcoma. Techniques for caval reconstruction after tumor resection vary widely. Our single-center experience serves as one of the largest reviews of caval reconstruction using polytetrafluoroethylene (PTFE) interposition grafts published in the past 10 years. Methods: We conducted a single-center retrospective review of all patients who had undergone surgical resection of IVC leiomyosarcomas since January 1, 2007. Information regarding the procedure and patient-specific data was obtained from the institution’s electronic medical record. Results: We identified 4 patients (3 women and 1 man) who had undergone surgical resection for IVC leiomyosarcoma with PTFE graft reconstruction. Adjunct procedures (i.e., arteriovenous fistulas) were not used to maintain graft patency. There was no perioperative mortality within our patient population. One patient returned within 30 days with an acute kidney injury associated with a partially occlusive thrombus in the proximal part of the PTFE conduit. Another patient was found to have infolding of the PTFE graft due to inappropriate graft oversizing at the time of the index operation. Two patients developed distant metastases within a year of surgery, despite having tumor-free margins at the time of the initial operation. All the PTFE interposition grafts remained patent throughout the follow-up without the need for an additional intervention. Conclusions: PTFE interposition graft may be a safe and effective conduit for caval reconstruction after resection of a primary leiomyosarcoma of the IVC, but further research is necessary to establish appropriate management guidelines.
INTRODUCTION Primary leiomyosarcoma of the inferior vena cava (IVC) is a rare soft tissue sarcoma, with approximately 300 published cases reported in the
Presented at the 2018 Vascular Annual Meeting in Boston, Massachusetts, on June 21, 2018. Declaration of Interest: A.G.K. and A.K.J. have no possible conflicts of interest to declare. M.K.E. has received honoraria from Prairie Education and Research Cooperative (Bard) for service on the LEVANT 2 clinical events committee; from Silk Road Medical, Inc. for service on the Roadster clinical events committee; and from W. L. Gore & Associates for service as a thoracic endovascular aneurysm repair course director. H.E.R. has received honoraria from W. L. Gore & Associates and Abbott Laboratories as a speaker.
literature.1 Although rare, a diagnosis of IVC leiomyosarcoma carries with it a poor prognosis, even in patients who undergo radical resection with or without neoadjuvant chemotherapy and radiation.2,3
Correspondence to: Mark K. Eskandari, MD, Division of Vascular Surgery, Northwestern University Feinberg School of Medicine, 676 N. St. Clair, Suite 650, Chicago IL, 60611, USA; E-mail: [email protected] Ann Vasc Surg 2019; 58: 289–294 https://doi.org/10.1016/j.avsg.2018.12.068 Ó 2019 Elsevier Inc. All rights reserved. Manuscript received: October 2, 2018; manuscript accepted: December 5, 2018; published online: 13 February 2019
Division of Vascular Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL.
289
290 Kalluri et al.
Diagnosis and treatment of IVC leiomyosarcoma require a multidisciplinary approach in which surgical reconstruction is a major component.4,5 Techniques for reconstruction have varied widely in the published vascular literature, making it difficult to form a consensus on the most appropriate reconstruction strategy.6,7 This is particularly true in cases where the IVC is not amenable to patch repair or primary repair and requires an interposition conduit for reconstruction to obtain an adequate negative surgical margin. The purpose of this case series is to document our center’s experience with IVC reconstruction using polytetrafluoroethylene (PTFE) graft as a conduit for interposition. A PTFE interposition graft was used for IVC reconstruction in 4 cases included in this review, making it one of the largest single-center case series evaluating the efficacy of PTFE interposition graft as a conduit for caval reconstruction.
METHODS This study was reviewed by and received approval from our center’s institutional review board; because data were deidentified, informed consent was waived. We reviewed the electronic medical record (Cerner Powerchart) at our medical center for all cases of IVC leiomyosarcoma resection performed by vascular surgeons between 2007 and 2017. We collected patient-specific data, including demographic information, clinical presentation, operative details, relevant imaging, and follow-up duration. Any cases for which the final pathological diagnosis was not leiomyosarcoma of the IVC were excluded from this review. As described previously, all cases of IVC leiomyosarcoma resection were performed by vascular surgeons, although the surgical team was always multidisciplinary in nature, including surgical oncology and urology (depending on renal vein involvement). The decision to operate is made as a consensus between the involved members of the multidisciplinary team, usually based on preoperative cross-sectional imaging and metastatic workup, as deemed appropriate by the medical and surgical oncologists. Preoperative cross-sectional imaging allows for identification of a mass involving the vena cava; however, the diagnosis of leiomyosarcoma is confirmed based on histopathology from the tumor specimen obtained intraoperatively. The standard surgical approach involves beginning with full mobilization of the colon and a wide Kocher maneuver to expose the IVC. After
Annals of Vascular Surgery
encircling the IVC and both renal veins, the dissection continues cephalad to dissect and ligate the caudate branches. Along the length of the exposed cava, the lumbar branches are ligated and divided. Once the level of dissection is confirmed to be well above and below the extent of the leiomyosarcoma (based on palpation), a therapeutic dose of intravenous heparin (80 units of heparin per kilogram body weight) is systemically administered. The IVC is then clamped proximally (above the tumor and below the hepatic veins) and distally below the tumor margin. If the tumor is found to invade the intima of the vena cava, it is then resected en bloc with the involved IVC to provide adequate margins widely free of tumor burden; if the tumor involves 50% of the caval circumference or more, the entirety of the involved IVC is resected and reconstructed with PTFE graft, sewn in an endto-end fashion with 4e0 polypropylethylene suture. The renal veins are then flushed, followed by flushing the cava proximally and distally, before restoring flow within the vessel. Follow-up surveillance after hospitalization was determined as a multidisciplinary approach, with the surgical and medical oncology teams treating the patient. Follow-up imaging involved either computed tomography scans or magnetic resonance imaging, both with and without intravenous contrast. The scans were all interpreted by attending radiologists, who evaluated for both evidence of tumor recurrence and patency of the reconstructed IVC. Preliminary surveillance scans were performed within the first 6 months after surgery; the need and timing for subsequent and long-term surveillance imaging was determined by the oncology teams.
RESULTS We identified 4 patients (3 women and 1 man) who had undergone surgical resection for IVC leiomyosarcoma. The average age of these patients was 56.5 years (range: 50e61 years; median: 57.5 years). The most common presenting symptom was abdominal pain, which manifested in 3 patients; in addition, 2 patients complained of flank pain and back pain. Physical examination was benign in most patients; only one patient presented with bilateral lower extremity edema. The clinical presentation prompted initial diagnostic cross-sectional imaging in each of these patients. Pathological review of the surgically resected tissue was performed by attending surgical pathologists. Primary leiomyosarcoma of the IVC was the
Volume 58, July 2019
PTFE conduit for IVC reconstruction
291
Fig. 1. Intraoperative PTFE graft images. Single patient intraoperative images demonstrating proximal (A) and distal (B) anastomoses of the PTFE graft.
Table I. Anatomic and procedure-related details for each patient with caval reconstruction after surgical resection of IVC leiomyosarcoma Patient number
1 2 3 4
Tumor location
Between renal and hepatic veins Infrarenal Between renal and hepatic veins Between renal and hepatic veins
Tumor size (cm)
IVC diameter (mm)
Repair type
5.2
12e14
18-mm PTFE interposition graft
9.8 4.5
24e26 18e21
24-mm PTFE interposition graft 18-mm PTFE interposition graft
18e20
20-mm PTFE interposition graft with reimplantation of the right renal vein
10
final pathological diagnosis in all 4 cases with no evidence of tumor at the surgical margin (R0 resection). All tumors were found to be either moderate or high grade; staging via the standard tumor, node, metastasis cancer staging system yielded T2 leiomyosarcomas in all cases. Based on a previously published anatomical classification system to localize leiomyosarcomas of the IVC, one tumor was found in the lower segment of the IVC (inferior to the renal veins), whereas 3 were found in the middle segment (between the renal veins and the hepatic veins).8 All 4 patients in our review underwent surgical reconstruction of the IVC with a PTFE interposition graft (Fig. 1). Adjunct procedures were uncommon; one patient required left nephrectomy, ureterectomy, and adrenalectomy for R0 resection, whereas another required reimplantation of the right renal vein. No patients received an arteriovenous fistula to help maintain graft patency. Our treatment
approaches for each individual patient are summarized in Table I. None of our patients died in the perioperative period. One patient was readmitted with acute kidney injury in the setting of a partially occlusive thrombus in the proximal part of the reconstructed IVC (Fig. 2). Two patients were diagnosed with distant metastases within 1 year of surgery. Our follow-up ranged from 9 months to 29 months (median: 18.5 months); none of these patients required operative reintervention, and all maintained patency of the IVC during their respective follow-up periods. All patients were maintained on prophylactic anticoagulation (5,000 units of subcutaneous heparin administered every 8 hr) postoperatively. One patient was empirically prescribed 3 months of therapeutic anticoagulation with warfarin upon discharge, whereas the other 3 patients were discharged without any anticoagulation prescription. Of the latter 3
292 Kalluri et al.
Fig. 2. Partially occlusive thrombus in the proximal segment of the PTFE graft. Coronal computed tomography scan depicting postoperative partially occlusive thrombus in the proximal portion of the PTFE graft after en bloc resection of leiomyosarcoma and IVC reconstruction.
patients, 1 patient was started on therapeutic anticoagulation (warfarin) indefinitely 1 month after the surgery due to development of partially occlusive thrombus in the proximal part of the reconstructed IVC; a second patient was started on short-term therapeutic anticoagulation (3 months) when surveillance imaging demonstrated infolding of the PTFE graft.
DISCUSSION This series is one of the larger single-center reviews of caval reconstruction using a PTFE interposition graft after resection for primary IVC leiomyosarcoma performed within the last 10 years. The interposition grafts remained patent throughout the follow-up period without any evidence of disease recurrence at the surgical resection site. There was no perioperative mortality or reintervention required in any of our patients. Two patients did have to be started on therapeutic anticoagulation due to graft-related nonocclusive thrombus formation; one patient developed a partially occlusive thrombus at the proximal anastomosis, whereas another patient developed infolding of the PTFE graft. We did not need to rely on any adjunct procedures or reinterventions to maintain patency of the interposition PTFE grafts. In 2006, Kieffer et al.4 described the use of PTFE as a conduit for caval
Annals of Vascular Surgery
reconstruction in 13 patients with primary leiomyosarcomas of the IVC. Based on patency outcomes, this group concluded that arteriovenous fistulas were an important part of IVC reconstruction with PTFE to maintain patency after repair. Given that all the PTFE interposition grafts in our cohort remained patent throughout the follow-up period, our experience would suggest that the creation of an AV fistula is not necessary to avoid graft thrombosis. Even in the case of the patient who developed a nonocclusive thrombus at the proximal anastomosis, an arteriovenous fistula would not have been likely to prevent the thrombus from forming. In this case, the thrombus may have formed due to a technical issue at the proximal surgical anastomosis, given the focal nature of the thrombus and the close temporal proximity between thrombus development and the index operation; another factor that may have influenced thrombus development was the need for reimplantation of the right renal vein in this patient. There are no consensus guidelines to determine the appropriate size for PTFE graft used for reconstruction of the IVC. Based on a review of literature, PTFE graft diameters ranging from 14 to 18 mm appear to be most common, although many times, decisions regarding graft sizing are made intraoperatively depending on the size of the IVC.9 In this review, we encountered one patient who had a preoperative IVC diameter of 24e26 mm; as a result, we elected to use a 24-mm PTFE interposition graft in this patient. Postoperative surveillance imaging in this patient demonstrated infolding of the graft (Fig. 3). This is likely due to the eventual normalization of the IVC diameter in a low-pressure system once any obstruction from the tumor was relieved. Although this complication may have been prevented by the use of a ring-reinforced PTFE graft, none of the other cases exhibited such graft kinking; although the IVC experiences low flow velocity, there is still high flow volume and insignificant external compression, which allows for safe use of nonringed PTFE grafts, as we used in each of the presented cases. The most likely etiology for the infolding is excessive oversizing of the graft relative to the rather compliant IVC, which is also distended intraoperatively. Thus, we suggest using a smaller diameter PTFE graft in accordance with the range previously mentioned to avoid distortion of the graft postoperatively. Similarly, there are also no consensus guidelines for postoperative anticoagulation after IVC reconstruction with PTFE. The decision for anticoagulation postoperatively is typically dependent on
Volume 58, July 2019
PTFE conduit for IVC reconstruction
293
Fig. 3. Postoperative surveillance CT scan of PTFE graft used as a conduit for interposition during caval reconstruction: (A) axial cut of 18-mm PTFE graft demonstrating normalization of IVC; (B) axial cut of 24-mm
PTFE graft demonstrating graft infolding; (C) coronal cut of 18-mm PTFE graft; (D) coronal scan of 24-mm PTFE graft demonstrating graft infolding.
surgeon discretion, unless there are complications that mandate anticoagulation. Close surveillance imaging is critical in patients who have undergone IVC reconstruction with PTFE, and any patients with evidence of thrombus within the PTFE or native IVC on surveillance imaging should promptly be started on anticoagulation to prevent graft thrombosis. As with all studies pertaining to rare pathology, the small sample size of our patient population limits the generalizability of our results and conclusions. That being said, our data do bring to light some important considerations in the surgical and postoperative management of patients undergoing PTFE reconstruction for IVC leiomyosarcoma. It is our goal to investigate this rare disease on a larger scale involving multiple centers
to provide more evidence-based guidelines for appropriate management of patients with primary leiomyosarcoma of the IVC.
CONCLUSION PTFE interposition grafts for caval reconstruction after en bloc resection of IVC leiomyosarcomas may be safe, but further investigation is necessary to confirm the efficacy of this conduit. A multicenter review of a larger cohort of patients may help establish more definitive guidelines with regard to the use of adjunct procedures to maintain graft patency, appropriate sizing of the conduit, and the need and appropriate duration for postoperative systemic anticoagulation.
294 Kalluri et al.
Annals of Vascular Surgery
REFERENCES 1. Alkhalili E, Greenbaum A, Langsfeld M, et al. Leiomyosarcoma of the inferior vena cava: a case series and review of the literature. Ann Vasc Surg 2016;33:245e51. 2. Dzinich C, Gloviczki P, van Heerden JA, et al. Primary venous leiomyosarcoma: a rare but lethal disease. J Vasc Surg 1992;15:595e603. 3. Mingoli A, Cavallaro A, Sapienza P, et al. International registry of inferior vena cava leiomyosarcoma: analysis of a world series on 218 patients. Anticancer Res 1996;16: 3201e5. 4. Kieffer E, Alaoui M, Piette JC, et al. Leiomyosarcoma of the inferior vena cava: experience in 22 cases. Ann Surg 2006;244:289e95. 5. Hines OJ, Nelson S, Quinones-Baldrich WJ, et al. Leiomyosarcoma of the inferior vena cava: prognosis and comparison
6.
7.
8.
9.
with leiomyosarcoma of other anatomic sites. Cancer 1999;85:1077e83. Wachtel H, Jackson BM, Bartlett EK, et al. Resection of primary leiomyosarcoma of the inferior vena cava (IVC) with reconstruction: a case series and review of the literature. J Surg Oncol 2015;111:328e33. Kyriazi MA, Stafyla VK, Chatzinikolaou I, et al. Surgical challenges in the treatment of leiomyosarcoma of the inferior vena cava: analysis of two cases and brief review of the literature. Ann Vasc Surg 2010;24:826.e13e7. Mingoli A, Feldhaus RJ, Cavallaro A, et al. Leiomyosarcoma of the inferior vena cava: analysis and search of world literature on 141 patients and report of three new cases. J Vasc Surg 1991;14:688e99. Illuminati G, Calio FG, D’Urso A, et al. Prosthetic replacement of the infrahepatic inferior vena cava for leiomyosarcoma. Arch Surg 2006;141:919e24. discussion 924.
Background: Primary leiomyosarcoma of the inferior vena cava (IVC) is a rare soft tissue sarcoma. Techniques for caval reconstruction after tumor resection vary widely. Our single-center experience serves as one of the largest reviews of caval reconstruction using polytetrafluoroethylene (PTFE) interposition grafts published in the past 10 years. Methods: We conducted a single-center retrospective review of all patients who had undergone surgical resection of IVC leiomyosarcomas since January 1, 2007. Information regarding the procedure and patient-specific data was obtained from the institution’s electronic medical record. Results: We identified 4 patients (3 women and 1 man) who had undergone surgical resection for IVC leiomyosarcoma with PTFE graft reconstruction. Adjunct procedures (i.e., arteriovenous fistulas) were not used to maintain graft patency. There was no perioperative mortality within our patient population. One patient returned within 30 days with an acute kidney injury associated with a partially occlusive thrombus in the proximal part of the PTFE conduit. Another patient was found to have infolding of the PTFE graft due to inappropriate graft oversizing at the time of the index operation. Two patients developed distant metastases within a year of surgery, despite having tumor-free margins at the time of the initial operation. All the PTFE interposition grafts remained patent throughout the follow-up without the need for an additional intervention. Conclusions: PTFE interposition graft may be a safe and effective conduit for caval reconstruction after resection of a primary leiomyosarcoma of the IVC, but further research is necessary to establish appropriate management guidelines.
INTRODUCTION Primary leiomyosarcoma of the inferior vena cava (IVC) is a rare soft tissue sarcoma, with approximately 300 published cases reported in the
Presented at the 2018 Vascular Annual Meeting in Boston, Massachusetts, on June 21, 2018. Declaration of Interest: A.G.K. and A.K.J. have no possible conflicts of interest to declare. M.K.E. has received honoraria from Prairie Education and Research Cooperative (Bard) for service on the LEVANT 2 clinical events committee; from Silk Road Medical, Inc. for service on the Roadster clinical events committee; and from W. L. Gore & Associates for service as a thoracic endovascular aneurysm repair course director. H.E.R. has received honoraria from W. L. Gore & Associates and Abbott Laboratories as a speaker.
literature.1 Although rare, a diagnosis of IVC leiomyosarcoma carries with it a poor prognosis, even in patients who undergo radical resection with or without neoadjuvant chemotherapy and radiation.2,3
Correspondence to: Mark K. Eskandari, MD, Division of Vascular Surgery, Northwestern University Feinberg School of Medicine, 676 N. St. Clair, Suite 650, Chicago IL, 60611, USA; E-mail: [email protected] Ann Vasc Surg 2019; 58: 289–294 https://doi.org/10.1016/j.avsg.2018.12.068 Ó 2019 Elsevier Inc. All rights reserved. Manuscript received: October 2, 2018; manuscript accepted: December 5, 2018; published online: 13 February 2019
Division of Vascular Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL.
289
290 Kalluri et al.
Diagnosis and treatment of IVC leiomyosarcoma require a multidisciplinary approach in which surgical reconstruction is a major component.4,5 Techniques for reconstruction have varied widely in the published vascular literature, making it difficult to form a consensus on the most appropriate reconstruction strategy.6,7 This is particularly true in cases where the IVC is not amenable to patch repair or primary repair and requires an interposition conduit for reconstruction to obtain an adequate negative surgical margin. The purpose of this case series is to document our center’s experience with IVC reconstruction using polytetrafluoroethylene (PTFE) graft as a conduit for interposition. A PTFE interposition graft was used for IVC reconstruction in 4 cases included in this review, making it one of the largest single-center case series evaluating the efficacy of PTFE interposition graft as a conduit for caval reconstruction.
METHODS This study was reviewed by and received approval from our center’s institutional review board; because data were deidentified, informed consent was waived. We reviewed the electronic medical record (Cerner Powerchart) at our medical center for all cases of IVC leiomyosarcoma resection performed by vascular surgeons between 2007 and 2017. We collected patient-specific data, including demographic information, clinical presentation, operative details, relevant imaging, and follow-up duration. Any cases for which the final pathological diagnosis was not leiomyosarcoma of the IVC were excluded from this review. As described previously, all cases of IVC leiomyosarcoma resection were performed by vascular surgeons, although the surgical team was always multidisciplinary in nature, including surgical oncology and urology (depending on renal vein involvement). The decision to operate is made as a consensus between the involved members of the multidisciplinary team, usually based on preoperative cross-sectional imaging and metastatic workup, as deemed appropriate by the medical and surgical oncologists. Preoperative cross-sectional imaging allows for identification of a mass involving the vena cava; however, the diagnosis of leiomyosarcoma is confirmed based on histopathology from the tumor specimen obtained intraoperatively. The standard surgical approach involves beginning with full mobilization of the colon and a wide Kocher maneuver to expose the IVC. After
Annals of Vascular Surgery
encircling the IVC and both renal veins, the dissection continues cephalad to dissect and ligate the caudate branches. Along the length of the exposed cava, the lumbar branches are ligated and divided. Once the level of dissection is confirmed to be well above and below the extent of the leiomyosarcoma (based on palpation), a therapeutic dose of intravenous heparin (80 units of heparin per kilogram body weight) is systemically administered. The IVC is then clamped proximally (above the tumor and below the hepatic veins) and distally below the tumor margin. If the tumor is found to invade the intima of the vena cava, it is then resected en bloc with the involved IVC to provide adequate margins widely free of tumor burden; if the tumor involves 50% of the caval circumference or more, the entirety of the involved IVC is resected and reconstructed with PTFE graft, sewn in an endto-end fashion with 4e0 polypropylethylene suture. The renal veins are then flushed, followed by flushing the cava proximally and distally, before restoring flow within the vessel. Follow-up surveillance after hospitalization was determined as a multidisciplinary approach, with the surgical and medical oncology teams treating the patient. Follow-up imaging involved either computed tomography scans or magnetic resonance imaging, both with and without intravenous contrast. The scans were all interpreted by attending radiologists, who evaluated for both evidence of tumor recurrence and patency of the reconstructed IVC. Preliminary surveillance scans were performed within the first 6 months after surgery; the need and timing for subsequent and long-term surveillance imaging was determined by the oncology teams.
RESULTS We identified 4 patients (3 women and 1 man) who had undergone surgical resection for IVC leiomyosarcoma. The average age of these patients was 56.5 years (range: 50e61 years; median: 57.5 years). The most common presenting symptom was abdominal pain, which manifested in 3 patients; in addition, 2 patients complained of flank pain and back pain. Physical examination was benign in most patients; only one patient presented with bilateral lower extremity edema. The clinical presentation prompted initial diagnostic cross-sectional imaging in each of these patients. Pathological review of the surgically resected tissue was performed by attending surgical pathologists. Primary leiomyosarcoma of the IVC was the
Volume 58, July 2019
PTFE conduit for IVC reconstruction
291
Fig. 1. Intraoperative PTFE graft images. Single patient intraoperative images demonstrating proximal (A) and distal (B) anastomoses of the PTFE graft.
Table I. Anatomic and procedure-related details for each patient with caval reconstruction after surgical resection of IVC leiomyosarcoma Patient number
1 2 3 4
Tumor location
Between renal and hepatic veins Infrarenal Between renal and hepatic veins Between renal and hepatic veins
Tumor size (cm)
IVC diameter (mm)
Repair type
5.2
12e14
18-mm PTFE interposition graft
9.8 4.5
24e26 18e21
24-mm PTFE interposition graft 18-mm PTFE interposition graft
18e20
20-mm PTFE interposition graft with reimplantation of the right renal vein
10
final pathological diagnosis in all 4 cases with no evidence of tumor at the surgical margin (R0 resection). All tumors were found to be either moderate or high grade; staging via the standard tumor, node, metastasis cancer staging system yielded T2 leiomyosarcomas in all cases. Based on a previously published anatomical classification system to localize leiomyosarcomas of the IVC, one tumor was found in the lower segment of the IVC (inferior to the renal veins), whereas 3 were found in the middle segment (between the renal veins and the hepatic veins).8 All 4 patients in our review underwent surgical reconstruction of the IVC with a PTFE interposition graft (Fig. 1). Adjunct procedures were uncommon; one patient required left nephrectomy, ureterectomy, and adrenalectomy for R0 resection, whereas another required reimplantation of the right renal vein. No patients received an arteriovenous fistula to help maintain graft patency. Our treatment
approaches for each individual patient are summarized in Table I. None of our patients died in the perioperative period. One patient was readmitted with acute kidney injury in the setting of a partially occlusive thrombus in the proximal part of the reconstructed IVC (Fig. 2). Two patients were diagnosed with distant metastases within 1 year of surgery. Our follow-up ranged from 9 months to 29 months (median: 18.5 months); none of these patients required operative reintervention, and all maintained patency of the IVC during their respective follow-up periods. All patients were maintained on prophylactic anticoagulation (5,000 units of subcutaneous heparin administered every 8 hr) postoperatively. One patient was empirically prescribed 3 months of therapeutic anticoagulation with warfarin upon discharge, whereas the other 3 patients were discharged without any anticoagulation prescription. Of the latter 3
292 Kalluri et al.
Fig. 2. Partially occlusive thrombus in the proximal segment of the PTFE graft. Coronal computed tomography scan depicting postoperative partially occlusive thrombus in the proximal portion of the PTFE graft after en bloc resection of leiomyosarcoma and IVC reconstruction.
patients, 1 patient was started on therapeutic anticoagulation (warfarin) indefinitely 1 month after the surgery due to development of partially occlusive thrombus in the proximal part of the reconstructed IVC; a second patient was started on short-term therapeutic anticoagulation (3 months) when surveillance imaging demonstrated infolding of the PTFE graft.
DISCUSSION This series is one of the larger single-center reviews of caval reconstruction using a PTFE interposition graft after resection for primary IVC leiomyosarcoma performed within the last 10 years. The interposition grafts remained patent throughout the follow-up period without any evidence of disease recurrence at the surgical resection site. There was no perioperative mortality or reintervention required in any of our patients. Two patients did have to be started on therapeutic anticoagulation due to graft-related nonocclusive thrombus formation; one patient developed a partially occlusive thrombus at the proximal anastomosis, whereas another patient developed infolding of the PTFE graft. We did not need to rely on any adjunct procedures or reinterventions to maintain patency of the interposition PTFE grafts. In 2006, Kieffer et al.4 described the use of PTFE as a conduit for caval
Annals of Vascular Surgery
reconstruction in 13 patients with primary leiomyosarcomas of the IVC. Based on patency outcomes, this group concluded that arteriovenous fistulas were an important part of IVC reconstruction with PTFE to maintain patency after repair. Given that all the PTFE interposition grafts in our cohort remained patent throughout the follow-up period, our experience would suggest that the creation of an AV fistula is not necessary to avoid graft thrombosis. Even in the case of the patient who developed a nonocclusive thrombus at the proximal anastomosis, an arteriovenous fistula would not have been likely to prevent the thrombus from forming. In this case, the thrombus may have formed due to a technical issue at the proximal surgical anastomosis, given the focal nature of the thrombus and the close temporal proximity between thrombus development and the index operation; another factor that may have influenced thrombus development was the need for reimplantation of the right renal vein in this patient. There are no consensus guidelines to determine the appropriate size for PTFE graft used for reconstruction of the IVC. Based on a review of literature, PTFE graft diameters ranging from 14 to 18 mm appear to be most common, although many times, decisions regarding graft sizing are made intraoperatively depending on the size of the IVC.9 In this review, we encountered one patient who had a preoperative IVC diameter of 24e26 mm; as a result, we elected to use a 24-mm PTFE interposition graft in this patient. Postoperative surveillance imaging in this patient demonstrated infolding of the graft (Fig. 3). This is likely due to the eventual normalization of the IVC diameter in a low-pressure system once any obstruction from the tumor was relieved. Although this complication may have been prevented by the use of a ring-reinforced PTFE graft, none of the other cases exhibited such graft kinking; although the IVC experiences low flow velocity, there is still high flow volume and insignificant external compression, which allows for safe use of nonringed PTFE grafts, as we used in each of the presented cases. The most likely etiology for the infolding is excessive oversizing of the graft relative to the rather compliant IVC, which is also distended intraoperatively. Thus, we suggest using a smaller diameter PTFE graft in accordance with the range previously mentioned to avoid distortion of the graft postoperatively. Similarly, there are also no consensus guidelines for postoperative anticoagulation after IVC reconstruction with PTFE. The decision for anticoagulation postoperatively is typically dependent on
Volume 58, July 2019
PTFE conduit for IVC reconstruction
293
Fig. 3. Postoperative surveillance CT scan of PTFE graft used as a conduit for interposition during caval reconstruction: (A) axial cut of 18-mm PTFE graft demonstrating normalization of IVC; (B) axial cut of 24-mm
PTFE graft demonstrating graft infolding; (C) coronal cut of 18-mm PTFE graft; (D) coronal scan of 24-mm PTFE graft demonstrating graft infolding.
surgeon discretion, unless there are complications that mandate anticoagulation. Close surveillance imaging is critical in patients who have undergone IVC reconstruction with PTFE, and any patients with evidence of thrombus within the PTFE or native IVC on surveillance imaging should promptly be started on anticoagulation to prevent graft thrombosis. As with all studies pertaining to rare pathology, the small sample size of our patient population limits the generalizability of our results and conclusions. That being said, our data do bring to light some important considerations in the surgical and postoperative management of patients undergoing PTFE reconstruction for IVC leiomyosarcoma. It is our goal to investigate this rare disease on a larger scale involving multiple centers
to provide more evidence-based guidelines for appropriate management of patients with primary leiomyosarcoma of the IVC.
CONCLUSION PTFE interposition grafts for caval reconstruction after en bloc resection of IVC leiomyosarcomas may be safe, but further investigation is necessary to confirm the efficacy of this conduit. A multicenter review of a larger cohort of patients may help establish more definitive guidelines with regard to the use of adjunct procedures to maintain graft patency, appropriate sizing of the conduit, and the need and appropriate duration for postoperative systemic anticoagulation.
294 Kalluri et al.
Annals of Vascular Surgery
REFERENCES 1. Alkhalili E, Greenbaum A, Langsfeld M, et al. Leiomyosarcoma of the inferior vena cava: a case series and review of the literature. Ann Vasc Surg 2016;33:245e51. 2. Dzinich C, Gloviczki P, van Heerden JA, et al. Primary venous leiomyosarcoma: a rare but lethal disease. J Vasc Surg 1992;15:595e603. 3. Mingoli A, Cavallaro A, Sapienza P, et al. International registry of inferior vena cava leiomyosarcoma: analysis of a world series on 218 patients. Anticancer Res 1996;16: 3201e5. 4. Kieffer E, Alaoui M, Piette JC, et al. Leiomyosarcoma of the inferior vena cava: experience in 22 cases. Ann Surg 2006;244:289e95. 5. Hines OJ, Nelson S, Quinones-Baldrich WJ, et al. Leiomyosarcoma of the inferior vena cava: prognosis and comparison
6.
7.
8.
9.
with leiomyosarcoma of other anatomic sites. Cancer 1999;85:1077e83. Wachtel H, Jackson BM, Bartlett EK, et al. Resection of primary leiomyosarcoma of the inferior vena cava (IVC) with reconstruction: a case series and review of the literature. J Surg Oncol 2015;111:328e33. Kyriazi MA, Stafyla VK, Chatzinikolaou I, et al. Surgical challenges in the treatment of leiomyosarcoma of the inferior vena cava: analysis of two cases and brief review of the literature. Ann Vasc Surg 2010;24:826.e13e7. Mingoli A, Feldhaus RJ, Cavallaro A, et al. Leiomyosarcoma of the inferior vena cava: analysis and search of world literature on 141 patients and report of three new cases. J Vasc Surg 1991;14:688e99. Illuminati G, Calio FG, D’Urso A, et al. Prosthetic replacement of the infrahepatic inferior vena cava for leiomyosarcoma. Arch Surg 2006;141:919e24. discussion 924.