During pancreatoduodenectomy with venous resection for pancreatic cancer, end-to-end anastomosis is the preferred option for PV or SMV reconstruction. However, when the extent of the PV or SMV resection precludes a simple anastomosis, a variety of vascular grafts can substitute for the resected segment. Because of increased risk of life-threatening thrombotic occlusion, prosthetic grafts are not used except in emergencies where speed is essential or when a suitable autologous vein graft cannot be found. According to the literature, effective replacements for the PV and SMV in elective procedures have included large-caliber vein grafts such as the internal jugular vein, left renal vein, great saphenous vein, external iliac vein, and superficial femoral vein [7]; alternatively, a channel could be fashioned from the falciform ligament [8]. Each potential autologous graft source has advantages and disadvantages. With the internal jugular and lower limb veins, graft harvesting from any segment may be straightforward but preparation of the required additional surgical field distant from the abdomen can be bothersome and time-consuming for the staff as well as a source of difficulty for the patient. The left renal vein may be obtained using the same operative field used for pancreatic surgery, but is sometimes too large for SMV reconstruction. Additionally, many surgeons hesitate to use it unless renal function is optimal. Still another disadvantage of a renal vein graft is that only a relatively short length can be safely harvested. Procurement of the great saphenous vein is largely free of potential complications, but its diameter is too small, requiring spiral reformation prior to grafting [9]; such remodeling is technically demanding and time-consuming. Shortcomings of an external iliac vein graft are congestion and unsightly edema in its territory, as well as pain and pressure sensations upon prolonged standing or walking [10].
Although the left renal vein or the internal jugular vein is usually chosen as a graft for SMV reconstruction at our institution, an ovarian vein graft was used in the present case. Several reports have described SMV reconstruction using gonadal veins [11,12,13]. Ochiai et al. [11] previously reported a case in which a right ovarian vein was used as a graft during pancreatoduodenectomy, although those authors customized the graft to increase its diameter. In other reports [12, 13] a customized gonadal vein graft was used similarly because the original diameter of the gonadal vein might be insufficient for reconstructing the SMV. Considering that a study of cadaveric ovarian veins showed an average diameter of 3.93 ± 1.11 mm [14], customization of an ovarian vein graft usually would be required for use in SMV reconstruction. In our case, using an ovarian vein showing preexisting dilation eliminated any need for customizing the graft and also was hoped to decrease the likelihood of future re-emergence of pelvic congestion symptoms.
While still in situ, the dilated ovarian vein chosen as a graft in the present patient may have been responsible for her previous symptoms of PCS, a disorder which has a prevalence of 10% to 40% in women over a wide age range. Symptoms of PCS include chronic pelvic pain or feelings of heaviness, dysmenorrhea, dyspareunia, urinary urgency, and perineal or lower limb varices. The underlying anatomic and physiologic abnormalities are ovarian vein dilation and insufficiency [2]. More than half of patients with ovarian vein varices have PCS [15]. The ovarian veins follow a caudal-rostral retroperitoneal course parallel with the spinal column until they drain into the renal vein on the left and into the inferior vena cava on the right, representing only a part of the complex venous network related to the female pelvis. In the study of cadaveric ovarian veins mentioned above with respect to their diameters, mean distances of the termination points of the right and left ovarian veins from the confluences of the right and left renal veins with the IVC were 28.12 ± 7.54 mm and 28.49 ± 5.76 mm, respectively [14].
Importantly, PCS results from a combination of factors [2, 15], and ovarian vein dilation is not the sole etiology. Nonetheless, such dilation contributes significantly to development of PCS as a consequence of vascular congestion reflecting retrograde flow in an incompetent ovarian vein. A previous report proposes an ovarian vein diameter exceeding 8 mm according to contrast CT or magnetic resonance imaging as a criterion for diagnosis of pelvic varices and PCS [16]. While the present patient had no symptoms of PCS at the time of pancreatic surgery, she had a history of severe dysmenorrhea in her premenopausal years and still had occasional feelings of pelvic heaviness.
Hysterectomy formerly was a treatment for PCS, but studies reported residual pain in 33% of patients and recurring symptoms in 20%. This led to a preference for surgical ligation or resection of ovarian veins. Bilateral laparoscopic ligation of ovarian veins has been gaining popularity among gynecologists, but surgical experience with ovarian vein ligation is anecdotal, consisting mainly of a few case studies [1]. A more recent treatment for PCS is percutaneous embolization; a high percentage of patients have reported symptom improvement [2]. At this writing, the patient has noted no recurrence of pelvic heaviness since the operation, but further observation remains necessary to establish efficacy of her ovarian vein resection in preventing symptom recurrence.
Diameters of our patient’s dilated right ovarian vein and the portion of the SMV to be resected and reconstructed were similar, so we chose this vein for the graft even though previous symptoms suggestive of PCS were no longer evident. Use of this vein eliminated any need for an additional surgical field or customizing a graft to increase its diameter. Future pelvic congestive symptoms also should be less likely in this patient. Good graft patency has been maintained postoperatively, and the patient has completed adjuvant chemotherapy.
