Effect of stifle flexion on the position of the cranial tibial artery relative to the proximal tibia in dogs

Effect of cranial tibial artery laceration on radiographic bone healing and perioperative complications in dogs undergoing tibial plateau leveling osteotomy

During tibial plateau leveling osteotomy (TPLO), the laceration of the cranial tibial artery (LCTA) may occur, and the ligation of the cranial tibial artery might lead to impaired blood supply to the osteotomy site. The present case-control study aimed to evaluate the effect of LCTA on TPLO healing and the occurrence of perioperative complications. The incidence and predisposing factors to LCTA were also investigated. Fourteen cases experiencing LCTA were retrospectively enrolled from medical records of two veterinary teaching hospitals (LCTA group), whereas 28 randomly selected TPLOs that did not experience LCTA were included in the control group. Signalment data, proximal tibial epiphysis conformation, osteotomy features, perioperative complications, and bone healing were compared between the two groups. Bone healing was evaluated using the modified radiographic union scale for tibial fracture and the visual analog scale. The mean incidence was 9.6%. Bodyweight was significantly higher in the LCTA group compared to the control group (P = 0.009). Dogs belonging to the LCTA groups were significantly younger (P = 0.01). Intraoperative hypotension was significantly overreported in the LCTA group (P = 0.0001). None of the other variables differed significantly between the two groups. Dogs' size seems to be a predisposing factor, with dogs weighing >15 kg having 22 times more chance of experiencing LCTA. Due to the well-developed collateral blood supply of the canine hindlimb, LCTA and the closure of the cranial tibial artery did not appear to delay the radiographic bone healing or affect the incidence of perioperative complications.

Delayed Life-Threatening Hemorrhage Caused by Cranial Tibial Artery Pseudoaneurysm in Two Dogs

Two adult dogs were presented at 25 and 30 days following tibial external skeletal fixator placement (case 1) and tibial plateau leveling osteotomy (case 2), respectively. Clinical signs at presentation for each of them included acute onset lethargy, non-weight-bearing lameness, and hemorrhage at the surgical site with large hematoma formation. On admission, emergency whole blood transfusion was required in case 2 with a preoperative packed cell volume of 13%. Both dogs were diagnosed with pseudoaneurysm of the cranial tibial artery based on color Doppler ultrasonography. Additionally, computed tomography angiography was performed in one dog. Surgical treatment of the dogs included ligation of the cranial tibial artery supplying the pseudoaneurysm and curettage of hematoma. The surgery was completed without complications in case 1, but case 2 experienced inadvertent rupture of pseudoaneurysm with significant blood loss, which required another whole blood transfusion during the procedure. Both dogs had excellent functional recovery with no recurrence of clinical signs. We hypothesized that pseudoaneurysms were primarily caused by trauma secondary to placement of surgical implants or osteotomy. For orthopedic surgeons, it is important to recognize clinical signs of a potential tibial arterial pseudoaneurysm, as early surgical intervention may prevent loss of limb or life.

Rotation of the Tibial Plateau Segment to Control Arterial Haemorrhage during Tibial Plateau Levelling Osteotomy: A Cadaveric Experimental Study and Nine Clinical Cases

OBJECTIVE

 The aim of this study was to describe a simple and effective method to control severe haemorrhage from intraoperative trauma to the cranial tibial artery (CTA) during tibial plateau levelling osteotomy (TPLO) and to report long-term outcomes.

STUDY DESIGN

 Cadaveric descriptive study and retrospective case series. A TPLO was performed in eight cadaveric limbs, followed by intentional laceration of the CTA under fluoroscopic guidance. Dissection of the limb was performed and the relationship between the CTA and the surrounding structures was evaluated. A computed tomography angiogram was performed following TPLO in one cadaveric limb. Medical records from cases that had intraoperative arterial bleeding between 2015 and 2019 were reviewed. Cases were included if bleeding was controlled by following the usual steps for TPLO. Radiographic follow-up 6 to 10 weeks postoperatively and long-term follow-up owner's questionnaire were available.

RESULTS

 During TPLO, the CTA is tightly compressed between the caudal aspect of the proximal tibia and the popliteal musculature. Rotation and compression of the proximal tibia followed by closure of the pes anserinus successfully controlled arterial bleeding during TPLO in nine clinical cases without the need for direct ligation.

CONCLUSION

 Continuing the usual steps of a TPLO can successfully control intraoperative bleeding from the CTA with no long-term complications. This technique should be considered in cases of arterial bleeding during TPLO before direct ligation.

Ex Vivo Evaluation of the Cranial Tibial Artery and Its Compression through Fragment Rotation during Tibia Plateau Levelling Osteotomy: An Angiographic Three-Dimensional Reconstruction

OBJECTIVE

 To illustrate the arterial vascularity of the proximal tibia three-dimensionally and to evaluate the impact of fragment rotation on the cranial tibial artery by tibia plateau levelling osteotomy (TPLO).

METHOD

 Radiographic angiography and computed tomography (CT) were performed on 12 pelvic limbs from six large-breed canine cadavers before and after TPLO. Three-dimensional (3D) models of the stifle, including osseous and vascular structures, were obtained, and the integrity of the cranial tibial artery was assessed. Post-TPLO CT images were used to analyze compression of the cranial tibial artery by the rotated fragment.

RESULTS

 The uncompressed cranial tibial artery caliber, measured proximally and distally to the osteotomy, was 9.52 mm² (6.07-18.90 mm²). In all adequately rotated fragments, the mean caliber of the artery on the level of the osteotomy was 1.57 mm² (0.89-2.93 mm²) after TPLO. This represented a significant decrease of approximately 81%. Only slight cross-sectional area decrease (8.8%) was seen in one limb, which was revealed to have insufficient fragment rotation (2.83 mm). Another limb only showed signs of stretching of the artery (31.51%), which was under-rotated and medially displaced. Pre-TPLO 3D reconstructions were mainly consistent with previous anatomic studies except for the distance between tibial cortex and cranial tibial artery, which appeared closer.

CONCLUSION

 Sufficient fragment rotation leads to compression of the cranial tibial artery. Intraoperative hemorrhage can be caused by laceration of the main cranial tibial artery or by multiple small branches reaching craniolaterally.