With the development of vascular surgery, the number of vascular operations has increased greatly, but we often neglect the immediate efficacy evaluation during the operation, so that postoperative anastomotic stenosis, obstruction or distal vascular lesions are not detected and treated in time, which affects the efficacy of the operation and even leads to the failure of the operation, increasing the patient’s pain and amputation rate, and even threatening the patient’s life safety. Since 2003, our department has carried out routine angiography during vascular surgery for immediate efficacy evaluation.
Our experience is summarized and reported as follows.
I. General information
There were 24 cases in this group, 19 males and 5 females, aged 32-79 years, with an average of 61.2 years. Among them, there were 10 cases of arteriosclerotic occlusion of lower limbs, 1 case of double lower limb arteriosclerosis with acute thrombosis, 2 cases of lower limb thrombo-occlusive vasculitis, 1 case of femoral artery thrombosis after left lower limb trauma, 1 case of left lower limb thrombosis sequelae and left iliac vein occlusion, 7 cases of lower limb artery embolism, and 2 cases of acute thrombosis of artificial blood vessels. Treatment: Bilateral femoral artery bypass of the abdominal aorta with artificial vessels and embolization of the abdominal aorta and right femoral artery by dissection in 1 case. Thirteen cases were treated with artificial vessels or their own saphenous vein for femoral-state or anterior and posterior tibial artery bypass, including one case with femoral artery endarterectomy. One case of suprapubic diversion of the contralateral saphenous vein was performed. All 17 cases underwent angiography and ultrasound before surgery, and 7 cases only underwent ultrasound.
II. Angiography method
After the completion of bypass or embolization, a tube was placed at the proximal normal vessel or artificial vessel after puncture with a trocar needle, and 76% pantopamine or Onepac was diluted from 20 ml to 40 ml and injected under pressure with a 50 ml syringe. If the lesion is distant or the distant vessels need to be understood, the imaging can be performed in stages. After the contrast is completed, the trocar needle is removed and local pressure is applied to stop the bleeding. If a problem is found, it can be re-examined after the problem is solved.
III. Imaging results
In this paper, 24 patients with intraoperative angiography, 1 case had partial failure of angiography due to inexperience, and only the proximal anastomosis was shown. 17 cases showed that the anastomosis was open and the distal outflow tract was good. 1 patient with thrombo-occlusive vasculitis had a low outflow tract and underwent autologous saphenous vein femoral-anterior and posterior tibial bypass, and intraoperative angiography revealed that the distal outflow tract was poorly visualized and was not further treated. After the procedure, the bypass vessel became obstructed, resulting in failure of the procedure. The patient’s symptoms did not improve.
In two of the patients with femoral artery dissection for embolization, there was still a thrombus in the national artery at the end of the procedure, and the distal outflow tract was not visualized. In the patient with suprapubic diversion of the saphenous vein, intraoperative imaging revealed that the saphenous vein was not satisfactorily dilated, and after blocking the distal end, it was dilated with saline pressure from the proximal end, and then reconstructed to show good dilatation. 2 patients with acute thrombosis of artificial vessels were found to have stenosis of the lower anastomosis after embolization and were relieved by local dilatation with Forgaty catheter.
IV. Discussion
The success of vascular surgery depends on the operator’s comprehensive understanding of vascular disease and his vascular anastomosis technique as well as the condition of the patient’s vascular lesion. However, unexpected circumstances and complications such as dislodged emboli and postoperative anastomotic stenosis may sometimes occur and affect the outcome. It is difficult to achieve technical perfection in every procedure or to anticipate every intraoperative vascular lesion and accident. Intraoperative angiography can be a good choice for this purpose.
In vascular surgery of the extremities, suturing is sometimes difficult due to the thinness of the vessels and anatomical reasons, and there are often problems such as anastomotic stenosis and occlusion. The incidence of graft thrombosis within 30 days after surgery is about 2%-7% [1], with poor vascular anastomosis technique and improper selection of outflow tract being the main causes. As the narrowed vessel is prone to thrombosis or intimal hyperplasia due to hemodynamic changes, the ischemic symptoms after occlusion may appear only a few days after surgery or even after discharge from the hospital.
This increases the cost and pain for the patient. When using the saphenous vein as a material for bypass or diversion, inadequate dilation and distortion of the saphenous vein can occur, thus affecting its patency rate. In this article, there was a case of post-bypass anastomotic stenosis with thrombosis and inadequate dilation of the saphenous vein during diversion, which was detected by intraoperative angiography and treated in each patient.
For emergency patients such as limb artery embolism, acute thrombosis or vascular injury, most of them do not have time to perform angiography and operate only by ultrasound examination and medical history and signs, which makes other lesions such as arterial stenosis to be overlooked or multiple injuries of blood vessels to be missed, and at the same time, intraoperative cannot determine whether the thrombus is missed or not. Before intraoperative angiography, we found that sometimes we could not do anything when we felt that the embolus had been removed but the distal blood return was still poor, or the embolus catheter could only be inserted to the national artery.
The amputation rate of these patients is higher after surgery. After intraoperative imaging, two patients with arterial embolism were found to have thrombus in the national artery at the end of surgery, and their distal outflow tracts were not visualized, and after the Forgaty catheter was inserted to remove the embolus, another imaging was performed, and the distal end was clear and the outflow tracts were well visualized. In patients with vascular trauma, especially crush injuries, there are sometimes multiple injuries to the vessels, and ultrasound is difficult to detect vascular injuries below the first injury because there is no blood flow. Intraoperatively, the surgeon may only treat the first injury, but cannot determine whether there is a distal vascular injury and where it is.
Intraoperative angiography can give the surgeon a clear answer immediately. From the above, we can see that the use of intraoperative angiography in vascular surgery can greatly reduce postoperative complications. Intraoperative contrast is performed under direct vision, with the contrast agent diluted and injected under pressure with a syringe, and the film is taken with an ordinary mobile film camera. It has the advantages of being less invasive, simpler, less expensive, and can be performed repeatedly.
When performing intraoperative contrast, the following points should be noted.
1, the choice of the contrast interposition point: we believe that it is best to puncture on the own vessel proximal to the first anastomosis, which on the one hand can show the situation of the first anastomosis, and on the other hand is conducive to compression hemostasis, while it is difficult to compression hemostasis at the puncture point after artificial vessel puncture, and often requires suturing.
2, the choice of contrast film time: If there is a DSA machine in the operating room, the choice of film time is not a problem, but many hospitals do not have this condition, and mostly use ordinary mobile film camera for film, which has the problem of when to film during the process of pushing the contrast agent, too early, the distant segment is not developed, too late, the near segment of the contrast agent has flowed away.
In our first angiogram, we had both a premature uptake and a non-developed distal segment. Later, we used 40 ml of diluted contrast agent and pushed it in continuously, and took the film when it reached 30 ml. The remaining 10 ml of contrast agent was pushed in at the same time to ensure that the contrast agent was always injected during the film. The effect is good.
3. Choice of interposition needle: During the imaging process, we found that direct interposition with the injection needle often penetrates the vessel when pushing the contrast agent under pressure, while using the trocar needle does not have this problem.4 Since some vascular procedures may have embolus dislodgement or occult lesions in distant segments, and intraoperative imaging is affected by the size of the film, each imaging can only show a local, in order to prevent intraoperative omission of distant lesions. We believe that contrast throughout the whole procedure is necessary.