PMVT has become a potentially severe reported complication of LSG despite its rare frequency (4,5). In our case series, one patient was found to have Factor V Leiden mutation suggesting a secondary underlying cause of PMVT. However, in post LSG, the etiology of PMVT is multifactorial and can have additional intraoperative and postoperative factors (6,7). Unfortunately, the information regarding the thromboprophylaxis measures was not sufficiently provided in our two patients. CECT is considered a gold standard in detecting PMVT and bowel ischemia, with a sensitivity reaching 90 % (8). In our cases, CECT showed high accuracy in detecting the extent of PMVT and the degree of bowel insult, which determined the type of management and allowed us to plan the access to the portal system.
The management of PMVT depends on many factors such as the extension of thrombus, presence or not of bowel ischemia and infarction, and the general condition of the patient. The primary goal is to recanalize the affected veins to prevent secondary complications and further extension of thrombus.
There is remarkable poverty in the studies comparing between the various recanalization modes used in PMVT. This, however, can be achieved through systemic IV anticoagulation, CDT, combination therapy or surgical interventions. Systemic IV anticoagulation should be immediately initiated in all cases. It can solely achieve complete recanalization especially in the nonocclusive non-ischemic bowel.
In up to 80% of cases, it was found that long-term anticoagulation alone for a minimum of six months may also recanalize partial to complete thrombosis (9). While in another study, it was indicated that approximately 30 to 50% of patients would show significant results after systemic IV anticoagulation alone (9). These in contrast to another study (10), which suggested a failure rate of exceeding 65% (10) with heparin anticoagulation alone. Therefore, for a symptomatic patient with occlusive, partial to complete thrombosis bowel more rapid recanalization by adopting a combined therapy of systemic IV anticoagulation and CDT is needed (7,10). This was evidenced in 75 to 100% of PMVT patients with at partial venous recanalization was observed in patients receiving the combined with overall excellent success rates (11,12). However, more critically symptomatic cases can form great clinical challenge necessitating alternative more invasive interventions to reduce the thrombus burden (10). Emergency laparotomy, open thrombectomy and bowel resection, therefore, should not be delayed in suspected infarction or subsequent perforation (13). In our two cases, both patients were hemodynamically stable with the presence of mild abdominal tenderness in case # 2 for whom a limited bowel resection was performed after CDT. Both ultimately received combined therapy with trans-hepatic and trans-splenic approaches, which showed effective and safe results in resolving the thrombosis.
CDT for the treatment of PMVT can proceed in two ways. First, direct trans-venous approach can be combined with mechanical or suction thrombectomy, balloon angioplasty, and stenting. CDT is effective in the setting of symptomatic acute and subacute PMVT with no evidence of bowel infarction. The trans-jugular intrahepatic portosystemic shunt (TIPS), although technically more challenging, is usually recommended (14). This technique can be used in the presence of abnormal deranged coagulation, causing less intraperitoneal bleeding than the trans-hepatic or trans-splenic approaches (14). The percutaneous trans-hepatic technique, usually performed under ultrasound guidance, is a known option to access PMVT. It carries the risk of bleeding, primarily if large catheters or sheaths are being used during thrombolysis or thrombectomy with hemodynamic instability rates of as high as 60% (11). The ultrasound-guided percutaneous trans-splenic technique is another direct way to access the portal system in which the trans-hepatic approach is challenging. It still carries a higher bleeding risk compared to TIPS and trans-hepatic approaches (15). Therefore, the decision for this approach should only be taken if the other options are undesirable. This is why we opted for the trans-splenic approach in case 2, which showed extended intrahepatic portal vein thrombosis in the CECT, making the trans-hepatic puncture of the portal vein branches challenging to obtain under ultrasound guidance. In both patients, the access tracks' embolization using absorbable gelatin sponge was performed to prevent bleeding complications while withdrawing the vascular sheaths (14,16,17).
Moreover, both patients had regular follow-up by venogram, and the vital signs were continuously monitored during tPA infusion. The duration of tPA infusion was based on the results obtained by the venogram and CECT. The infusion was interrupted once partial recanalization of the portomesenteric vein was obtained to reduce the bleeding risk.
The second way to proceed with CDT is by indirect approach using trans-femoral or trans-radial arterial accesses to insert multi-side hole perfusion catheter into the proximal superior mesenteric artery, which allows for thrombolytic agents infusion (14,18). Nevertheless, this method has a significant limitation as the total dose of infused tPA can result in locoregional toxicity. Also, in contrast to the direct methods, only thrombolysis and no other adjunctive interventions are applicable.
Finally, Surgical trans-ileocolic approaches were described, offering access to the portomesenteric vein. However, it is less suitable for mechanical techniques like thrombectomy or balloon angioplasty, or stenting (14).
In conclusion, PMVT is a relatively uncommon complication in patients undergoing LSG. Early detection and treatment based on high clinical suspicion and awareness of clinical presentation and imaging results are necessary to prevent long-term complications. Among the various approaches for recanalizing the portomesenteric vein thrombosis, including thrombolysis and thrombectomy techniques, CDT offers a safe and effective option to restore portal and mesenteric veins patency in symptomatic PMVT patients.