Ovarian vein bypass for renal allograft salvage in iliac vein atrophy: A case report and review of literature

Abstract

BACKGROUND

Failure of venous drainage during reperfusion is an uncommon but serious complication of kidney transplantation that can rapidly compromise graft viability.

CASE SUMMARY

We report a 51-year-old woman with end-stage kidney disease undergoing living-donor kidney transplantation after long-term hemodialysis and prior left femoral dialysis catheterization. Intraoperatively, the left external iliac vein was unexpectedly found to be markedly atrophic, measuring only 3 mm, whereas the graft renal vein measured 12 mm. After initial anastomosis to the external iliac vein, reperfusion caused immediate graft congestion, indicating inadequate venous outflow. A short great saphenous vein interposition graft was therefore used to create an additional drainage pathway from the renal vein to the ipsilateral ovarian vein, which measured 3.7 mm. The graft decompressed immediately, and urine output began within 1 minute. Renal function remained stable, with a serum creatinine level of 65.4 μmol/L at 7 months, and 8-month imaging confirmed bypass patency and adaptive venous enlargement.

CONCLUSION

A small ovarian vein with an autologous conduit can provide a salvage option for unexpected iliac venous pathology in kidney transplantation.

Key Words: Kidney transplantation; Venous outflow obstruction; Saphenous vein graft; Ovarian vein; Graft loss; Case report

Core Tip: Venous outflow complications during kidney transplantation are uncommon but may threaten immediate graft survival when conventional iliac venous drainage is not feasible. We describe a rare case of unexpected external iliac vein atrophy encountered intraoperatively, where renal allograft venous outflow was successfully salvaged using an ovarian vein bypass augmented with an autologous great saphenous vein conduit. This report emphasizes the importance of flexible intraoperative strategies and demonstrates that the ovarian vein can be adapted as an alternative venous drainage route after appropriate reconstruction, providing a practical solution for unexpected iliac venous insufficiency during renal transplantation.

INTRODUCTION

Venous complications occur in approximately 0.1%-1.0% of kidney transplants and are associated with a high risk of graft loss[1-3]. Venous outflow failure at reperfusion is an uncommon but pivotal cause of early renal allograft dysfunction and graft loss[4,5]. Iliac venous pathology, particularly catheter-related stenosis or atrophy of the external iliac vein (EIV), may be underrecognized preoperatively and may only be discovered intraoperatively[4-6]. A delayed response can lead to progressive thrombosis of the renal vein[7] and eventual graft failure[8,9].

When the EIV is unsuitable, alternative strategies include venous anastomosis to the common iliac vein (CIV) or the inferior vena cava (IVC)[5,10,11]. The gonadal vein represents another potential option because it lies within the operative field and can provide systemic venous outflow, avoiding deeper caval or mesenteric exposure[12]. However, previously reported ovarian or gonadal vein reconstructions have generally involved collateral veins that were already enlarged by chronic venous obstruction. For example, Wong et al[10] described reconstruction using a 9-mm ovarian vein, and Alameddine et al[11] used a markedly dilated gonadal vein.

To our knowledge, intraoperative salvage of renal allograft venous outflow using a small-caliber ovarian vein combined with a great saphenous vein (GSV) interposition graft has not been previously described. We present a case of unexpected EIV atrophy recognized during living-donor kidney transplantation, in which a GSV-to-ovarian vein bypass achieved immediate graft decompression and sustained venous remodeling on follow-up.

CASE PRESENTATION

Chief complaints

A 51-year-old woman with a 10-year history of end-stage kidney disease was admitted with anuria and scheduled for living-donor kidney transplantation. Before transplantation, she had no lower-limb swelling, pain, or other symptoms suggestive of iliac venous obstruction.

History of present illness

The patient had been maintained on hemodialysis for the past 9 years. Six months before transplantation, she underwent parathyroidectomy for treatment of severe hypercalcemia. She was subsequently evaluated and listed for living-donor kidney transplantation.

History of past illness

The patient's vascular access history was notable for a complicated right groin dialysis catheter placement 9 years earlier, which resulted in vascular perforation requiring emergency laparotomy through a right paramedian incision extending to the groin for vascular control. Hemodialysis was subsequently performed via a left groin catheter for more than 1 month before conversion to a permanent arteriovenous fistula.

Personal and family history

The patient had no remarkable family history of kidney disease or hereditary disorders.

Physical examination

Physical examination on admission was unremarkable except for surgical scars from prior abdominal surgery and vascular access procedures.

Laboratory examinations

Pretransplant immunologic work-up demonstrated negative anti-human leukocyte antigen antibodies, a negative crossmatch, and a 2/6 human leukocyte antigen match. Before transplantation, the patient's serum creatinine level was 771.7 μmol/L.

Imaging examinations

Because of the patient’s prior right-sided vascular injury and surgery, transplantation into the left iliac fossa was planned. Preoperative duplex ultrasonography and computed tomographic angiography of the recipient were initially interpreted as showing no major iliac vascular abnormality. However, the recipient’s left EIV abnormality was missed on the initial preoperative computed tomography assessment. After the intraoperative finding of a markedly atrophic left EIV in the recipient, the preoperative computed tomography images (Figure 1) were retrospectively reconstructed and reviewed, confirming that the recipient’s left EIV was markedly small. Preoperative imaging of the donor’s left kidney suggested 2 renal arteries and 1 renal vein; intraoperatively, however, 3 renal arteries and 1 renal vein were confirmed. Nuclear renography estimated a donor glomerular filtration rate of 69.9 mL/minute, with 48% split renal function for the left kidney.

Figure 1 Preoperative computed tomography venography. A: Markedly atrophic left external iliac vein measuring approximately 3 mm in diameter (arrow). This small caliber was insufficient for adequate renal allograft venous drainage; B: Left ovarian (gonadal) vein measuring 3.7 mm in diameter at its maximal segment (arrow), identified as a potential alternative venous outflow pathway within the operative field.

FINAL DIAGNOSIS

During recipient exploration, an unexpected intraoperative finding was a markedly diminutive left EIV measuring only 3 mm in diameter (Figure 1A). This contrasted with the 12-mm graft renal vein, predicting a severe outflow mismatch. The final diagnosis was unexpected EIV hypoplasia causing severe renal allograft venous outflow insufficiency during kidney transplantation.

TREATMENT

Access to the CIV was technically challenging, and the ureter length was insufficient to permit a higher implantation site. Furthermore, the presence of 3 renal arteries requiring individual anastomoses rendered relocation to the common iliac artery technically impractical. Relocation to the right iliac fossa was not favored because of prior complex right-sided abdominal and groin surgery for catheter-related vascular perforation, with anticipated adhesions and difficult re-entry. Despite the patient’s history of left groin catheterization, she had no symptoms of iliac venous obstruction, and preoperative imaging was initially interpreted as showing no major iliac vascular abnormality. Therefore, a standard implantation was conducted: The renal vein was anastomosed end-to-side to the left EIV, and the 3 renal arteries were anastomosed end-to-side to the left external iliac artery (Figure 2A).

Figure 2 Intraoperative findings. A: After clamp release, the left renal vein became markedly distended and the graft appeared congested and tense, consistent with inadequate outflow; B: Salvage bypass using an end-to-side great saphenous vein interposition graft from the renal vein to the left ovarian vein, creating an additional venous drainage pathway.

Upon reperfusion, the allograft immediately became tense and congested; the renal vein distended, confirming inadequate outflow through the hypoplastic EIV (Figure 2A). Arterial inflow was temporarily reduced by reclamping the renal artery while alternative venous drainage options were assessed. Survey of the regional venous anatomy revealed no suitable collaterals except for the superior segment of the ipsilateral ovarian vein, which measured 3.7 mm in diameter (Figure 1B). Because the distal portion of the ovarian vein divided into a plexiform network, the bypass was constructed at the site of maximal caliber. A segment of the GSV was harvested and used as an interposition conduit. An end-to-side anastomosis was performed between the recipient renal vein and the ovarian vein via the GSV graft, with a 1-cm-wide beveled opening created to optimize the luminal area and reduce the risk of anastomotic stenosis (Figure 2B and C). After declamping, the graft softened immediately and urine output commenced within 1 minute. Hemostasis was secured without complication.

OUTCOME AND FOLLOW-UP

The cold ischemic time was 8 minutes. This short duration was achieved by performing donor nephrectomy and recipient transplantation simultaneously in 2 adjacent operating rooms, allowing direct graft transfer after flushing. No complex back-table vascular reconstruction was required because separate arterial and venous anastomoses were planned. The warm ischemic time was 35 minutes, which was longer than expected for routine living-donor kidney transplantation. The serum creatinine level decreased to 51.3 μmol/L after transplantation and was 53.9 μmol/L at discharge, indicating no clinically evident delayed graft function. Early postoperative Doppler ultrasonography demonstrated excellent perfusion with a resistive index of 0.56 and a small perinephric fluid collection (28 mm × 30 mm), which was likely a lymphatic collection. At 7 months, the serum creatinine level was 65.4 μmol/L.

At the time of transplantation, the patient received induction with tacrolimus (8 mg), mycophenolate sodium (720 mg), acyclovir (800 mg), basiliximab (20 mg), and methylprednisolone (480 mg). Maintenance immunosuppression consisted of tacrolimus, mycophenolate, and prednisolone. Postoperatively, the patient received heparin during the first 2 days after transplantation, followed by aspirin 81 mg once daily as antiplatelet therapy.

At 8 months, Doppler ultrasonography showed a graft measuring 113 mm × 60 mm × 55 mm, with preserved corticomedullary differentiation, no hydronephrosis, and patent triple arterial anastomoses with intrarenal velocities of 22-25 cm/second and a resistive index of 0.57 (Figure 3A and 3B). Venous assessment demonstrated renal vein outflow of 219.3 mL/minute and flow through the GSV conduit of 67.6 mL/minute (Figure 3C and 3D).

Figure 3 Follow-up ultrasonography at 8 months. A: Gray-scale imaging of the renal graft showing preserved corticomedullary differentiation without hydronephrosis; B: Color Doppler demonstrating homogeneous parenchymal perfusion; C: Spectral Doppler measurement at the renal vein showing an outflow volume of 219.3 mL/minute; D: Spectral Doppler measurement at the great saphenous vein conduit showing a flow of 67.6 mL/minute.

Magnetic resonance imaging without contrast confirmed patency of all 3 arterial anastomoses, a 9-mm GSV-ovarian vein conduit, and an ovarian vein with a maximal caliber of 6.3 mm (Figure 4). The patient experienced no thrombotic or surgical complications and was satisfied with the treatment outcome during follow-up.

Figure 4 Follow-up magnetic resonance imaging at 8 months. A: Great saphenous vein conduit dilated to 9.09 mm (arrow); B: Left ovarian vein enlarged to 6.03 mm (arrow); C: Patent triple arterial anastomoses supplying the renal graft (arrows).

DISCUSSION

Prolonged femoral venous catheterization for hemodialysis is a well-recognized cause of injury to the iliofemoral venous system[13]. In a prospective study using magnetic resonance venography, Weyde et al[4] demonstrated that external iliac or femoral venous stenosis occurred in nearly one-third of patients whose catheters remained in place for more than 4 weeks, whereas no stenosis was observed when catheterization lasted 2 weeks or less. In the present case, the patient had undergone prolonged femoral catheterization in the left groin following vascular injury on the contralateral side. This prior access represents the most plausible explanation for the markedly atrophic EIV encountered during transplantation. Notably, the patient had never developed ipsilateral lower-extremity edema or other overt symptoms, suggesting that catheter-related venous injury may remain clinically silent for years and only become evident intraoperatively. In retrospect, the venous abnormality was potentially detectable on preoperative imaging if the recipient iliac venous system had been assessed more carefully with dedicated venous-phase review and reconstruction. This case therefore underscores the need for meticulous preoperative venous screening in high-risk recipients, particularly those with prior femoral catheterization or pelvic vascular injury.

Venous outflow obstruction after kidney transplantation is uncommon but clinically serious[14,15]. Impaired venous drainage can result in graft congestion, progressive renal vein thrombosis, and rapid loss of allograft function if not corrected promptly[16]. Early signs may be subtle: Graft Doppler can appear normal even in the presence of systemic venous disease, as shown by cases where edema developed postoperatively and thrombus subsequently extended from the femoral system to the renal vein anastomosis, alongside deteriorating graft function requiring hemodialysis[16]. If unrecognized, the consequences include thrombus propagation, pulmonary embolism, and early graft loss. These observations underscore the importance of maintaining a high index of suspicion in recipients with a history of femoral catheterization or prior pelvic venous injury.

In long-standing ileocaval obstruction, robust collateralization is often evident, frequently via a dilated gonadal (ovarian) vein. Wong et al[10] reported a hypertrophied ovarian vein measuring 9 mm that successfully served as an outflow channel in the setting of IVC hypoplasia and iliac thrombosis. Similarly, Alameddine et al[11] described an intraoperative rescue in which a chronically thrombosed EIV extending to the CIV and infrarenal IVC was bypassed to a dilated ovarian vein, decompressing a congested graft. These reports illustrate the principle that longstanding venous obstruction can remodel collaterals into effective outflow channels.

By contrast, our patient’s ovarian vein measured only 3.7 mm in diameter, near the lower limit of normal[17], despite a 9-year history of dialysis and a chronically narrowed EIV (3 mm). This lack of adaptive collateralization implied markedly elevated prestenotic pressures and explained the acute congestion observed at reperfusion. Indeed, Rosenthal and Loo[18] documented similar physiology: In patients with iliac obstruction and absent antegrade IVC flow, EIV pressures were as high as 38 mmHg in the presence of poor collaterals.

When the EIV cannot provide adequate outflow, several alternative strategies have been described. Portal or mesenteric drainage has been employed in rare circumstances where the entire ileocaval axis is excluded. Aguirrezabalaga et al[19] and Gunawansa[20] described anastomosis to the superior mesenteric vein. As cited by Alameddine et al[11], Patel and Krishnamurthi[21] used the inferior mesenteric vein and Kumar et al[22] used the splenic vein, showing that portal tributaries can serve as alternative outflow channels. The rationale is that the portal system provides a capacious, low-pressure reservoir. Although these approaches provide access to a large venous reservoir, they require transperitoneal dissection and mobilization of abdominal viscera, exposing the patient to potential complications such as mesenteric bleeding, bowel injury, or postoperative ileus[18].

Direct caval implantation provides the most physiologic systemic outflow[23,24]. Pirenne et al[25] bridged the renal vein to the infrahepatic IVC with a long venous conduit in a patient with congenital absence of the infrarenal cava. Banerjee et al[26] reported IVC end-to-side implantation after bilateral iliac vein thrombosis. Although this approach can provide durable venous outflow, it requires deep retroperitoneal exposure and may prolong the ischemia time. In addition, long conduits are potentially susceptible to kinking or thrombosis[25,26].

In the present case, these alternative strategies were technically possible but impractical. Exposure of the CIV was limited, and the graft ureter length was insufficient to permit higher implantation. Furthermore, the presence of 3 renal arteries requiring separate arterial anastomoses made relocation of the graft technically complex. For these reasons, an intraoperative salvage strategy was pursued within the existing operative field.

The ovarian vein offered a convenient and anatomically accessible route for venous drainage. Although its caliber was relatively small, a short interposition graft using the GSV provided a compliant conduit that could accommodate increased flow. The renal allograft decompressed immediately after restoration of circulation, with brisk urine output within 1 minute of reperfusion. Follow-up imaging at 8 months confirmed durable patency of the venous bypass and demonstrated adaptive enlargement of both the saphenous vein conduit and the ovarian vein.

When conventional iliac venous outflow is unavailable, the ovarian vein offers an anatomically expedient alternative. It lies within the operative field, allows iliac fossa placement, and avoids the morbidity of mesenteric or caval exposure. Prior reports across pediatric and adult recipients demonstrate that the gonadal system can safely accommodate renal venous return[27,28]. An important advantage of this strategy is that it can be performed as an adjunct bypass without dismantling the initial renal vein-EIV anastomosis. Because the reconstruction is performed within the existing operative field, it may reduce the need for extensive dissection or graft relocation, thereby limiting additional operative complexity and ischemic time.

A potential limitation is size: In the absence of collateral enlargement, the ovarian vein may measure only 3-4 mm[17,29], raising concerns of insufficient drainage. In our case, we elected not to rely on the ovarian vein as the sole outflow because of its relatively small caliber. Instead, the stenotic EIV remained the primary drainage route, with the ovarian vein incorporated as a secondary outflow through the GSV conduit. This dual-channel strategy provided immediate decompression of the graft and allowed both venous pathways to remodel over time. Our follow-up imaging confirmed effective adaptive enlargement.

This adaptive remodeling highlights an important physiological advantage of autologous venous conduits. Unlike prosthetic bypasses, which are noncompliant and cannot remodel[16], autologous veins retain the capacity to dilate in response to increased hemodynamic demand[30]. In our patient, the GSV expanded to approximately 9.0 mm and the ovarian vein to 6.3 mm, suggesting progressive adaptation of the venous outflow pathway. This remodeling may reduce the risk of late stenosis and contribute to the long-term durability of the reconstruction.

This report is limited by its single-case design and the follow-up duration of 8 months. Intraoperative venous pressure was not measured, limiting objective assessment of hemodynamic improvement after bypass reconstruction. The broader applicability of this strategy will require additional experience and longer observation. Nevertheless, the present case demonstrates that even a small-caliber ovarian vein can function effectively as an adjunct venous outflow channel when combined with a compliant autologous conduit. In summary, when conventional iliac venous outflow is unavailable during kidney transplantation, the ovarian vein represents a practical and anatomically accessible alternative. Incorporating this vessel into a dual-channel drainage strategy with an autologous venous conduit can provide immediate graft decompression while allowing physiologic venous remodeling over time (Table 1).

Table 1 Timeline of the patient’s clinical course.

Time point	Event	Detail
10 years before transplantation	Diagnosis of end-stage kidney disease	The patient was diagnosed with end-stage kidney disease and later required renal replacement therapy
9 years before transplantation	Initiation of hemodialysis and development of vascular complication	Maintenance hemodialysis was initiated. Placement of a right groin dialysis catheter resulted in vascular perforation requiring emergency laparotomy and vascular repair. Temporary dialysis via a left groin catheter was performed before conversion to a permanent arteriovenous fistula
6 months before transplantation	Parathyroidectomy	The patient underwent parathyroidectomy for severe hypercalcemia during long-term dialysis
Preoperative evaluation	Transplant work-up	Immunologic evaluation showed negative anti-HLA antibodies and negative crossmatch with a 2/6 HLA match. Preoperative creatinine was 771.7 µmol/L. Imaging was initially interpreted as showing no major iliac vascular abnormality, and the patient was scheduled for left iliac fossa transplantation
Day 0 (Intraoperative management)	Kidney transplantation and intraoperative finding	Living-donor kidney transplantation was performed. Intraoperative exploration revealed a markedly hypoplastic left external iliac vein (3 mm), resulting in severe venous outflow mismatch with the 12-mm graft renal vein
Day 0 (Transplantation)	Venous outflow reconstruction	A bypass from the renal vein to the ipsilateral ovarian vein was created using a GSV interposition graft. After declamping, the graft immediately softened and urine output began within 1 minute
Early postoperative period	Initial graft function	Doppler ultrasonography showed excellent graft perfusion (resistive index: 0.56). Serum creatinine decreased to 51.3 µmol/L and was 53.9 μmol/L at discharge
Postoperative month 7	Clinical follow-up	Serum creatinine remained stable at 65.4 µmol/L with preserved graft function
Postoperative month 8	Imaging follow-up	Doppler ultrasonography demonstrated preserved corticomedullary differentiation, patent arterial anastomoses, and adequate venous outflow through the renal vein and GSV conduit. Magnetic resonance imaging confirmed patency of the 3 arterial anastomoses and the GSV-ovarian vein conduit

HLA: Human leukocyte antigen; GSV: Great saphenous vein.

CONCLUSION

When conventional iliac venous drainage is inadequate during kidney transplantation, alternative outflow strategies may be required to preserve graft viability. In this case, a small ovarian vein combined with a compliant autologous GSV conduit provided effective adjunct venous drainage and immediate graft decompression. The favorable intermediate-term patency and venous remodeling observed in this patient suggest that this dual-channel approach may be a feasible salvage option in selected cases of unexpected iliac venous insufficiency. However, because this report describes a single patient, longer follow-up and additional cases are needed to determine the long-term durability and broader applicability of this strategy.