End to side anastomosis
Although several living practice models have been proposed for this technique, few involve purely arterial vessels.
Currently, there has been no animal model available for practicing all three anastomoses in one operation. The aim of a study of Yin et al., was to develop a novel animal modelthat utilizes the rat abdominal aorta (AA), common iliac artery(CIAs), and the median sacral artery (MSA) for practicing these three types of anastomosis.
Eight adult Sprague Dawley rats were anesthetized and then laparotomized. The AA, MSA, and bilateral CIAs were exposed and separated from the surrounding tissues. The length and diameter of each artery were measured. The relatively long segment of the AA without major branches was selected to perform end-to-end anastomosis. One side of the CIAs (or AA) and MSA were used for end-to-side anastomosis. The bilateral CIAs were applied to a side-to-side and another end-to-side anastomosis.
Anatomical dissection of the AA, CIAs, and MSA was successfully performed on eight Sprague-Dawley rats; four arterial-to-arterial anastomoses were possible for each animal. The AA trunk between the left renal artery and right iliolumbar arteries was 15.60 ± 0.76 mm in length, 1.59 ± 0.15 mm in diameter, for an end-to-end anastomosis. The left CIA was 1.06 ± 0.08 mm in diameter, for an end-to-side anastomosis with the right CIA. The MSA was 0.78 ± 0.07 mm in diameter, for another end-to-side anastomosis with the right CIA or AA. After finishing end-to-side anastomosis in the proximal part of bilateral CIAs, the distal portion was juxtaposed for an average length of 5.6 ± 0.25 mm, for a side-to-side anastomosis.
This model can comprehensively and effectively simulate anastomosis used in revascularization procedures and can provide more opportunities for surgical education, which may lead to more routine use in microvascular anastomosis training. 1).
The purpose of a study was to compare 2 arterial models using common carotid arteries (CCAs) and common iliac arteries (CIAs) in rats.
The CIAs and CCAs were exposed in 10 anesthetized rats, and their lengths and diameters were measured. Also, the mobilization extent of each vessel along its contralateral counterpart was measured after each artery had been transected at its proximal exposure point. We also studied the technical advantages and disadvantages of each model for practicing end-to-side anastomosis.
The average diameters of the CCA and CIA were 1.1 and 1.3 mm, respectively. The average extent of mobilization along the contralateral vessel was 13.9 mm and 10.3 mm for CCA and CIA, respectively. The CCA model had the advantages of greater arterial redundancy (allowing completion of both suture lines extraluminally) and a minimal risk of venous injury. The main disadvantage of the CCA model was the risk of cerebral ischemia. The CIA model was not limited by the ischemic time and provided the technical challenge of microsurgical dissection of the common iliac vein from the CIA, although it had limited CIA redundancy.
Both CCA and CIA models could be efficiently used for practicing the end-to-side anastomosis technique. Each model provides the trainee with a specific set of advantages and disadvantages that could help with the optimal selection of the practice model according to trainee’s skill level 2).
A dolichoectatic intracranial vessel with multiple fusiform aneurysms on the same vessel segment is rare, and usually managed with a bypass with aneurysm trapping. This video demonstrates trapping and a double-barrel superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass to treat two fusiform aneurysms in a left dolichoectatic superior MCA trunk. A 46-year-old man with AIDS presented with aphasia and hemiparesis. IRB approval and patient consent were obtained. Both STA branches (frontal and parietal) were harvested. After widely splitting the sylvian fissure from its proximal portion to the angular gyrus, the two fusiform aneurysms on the superior MCA trunk were identified in the insular recess and the circular sulcus. The outflow artery from each aneurysm was identified and prepared for the bypass. The STA was transected, and both limbs were brought down into the fissure. After trapping the distal aneurysm, an end-to-end anastomosis of the parietal STA branch to the M2 MCA was performed. Thereafter, a second bypass was performed in an end-to-side fashion to an M2 branch from the base of the first aneurysm. The second aneurysm was then trapped. Indocyanine green angiography confirmed the patency of both bypasses. Complete aneurysm occlusion and bypass patency were also confirmed with postoperative angiography. The patient recovered from his pre-operative neurological deficits. This case demonstrates the efficacy of double-barrel STA-MCA bypass in combination with aneurysm trapping in a patient with a complex dolichoectatic superior MCA trunk aneurysm. It also highlights the advantage of using end-to-end anastomosis for deep recipients with limited access 3).
A 63-year-old man presented with repeat neurological symptoms such as dizziness, nausea, vomiting, dysarthria, left hemiparesis, and right hemianopsia. Magnetic resonance imaging revealed multiple posterior infarctions. Angiography revealed the VA to be occluded and reconstituted by collateral vessels. Considering the above results, we performed vertebral carotid artery transposition. However, several technical difficulties were encountered due to space limitations in the operative field and the limited length of the vessels to be anastomosed. To overcome such situations, we introduced a modified posterior wall end-to-side anastomosis technique 4).
In this 3-dimensional video, we perform a side-to-side and end-to-side double anastomosis using the parietal-branch of the superficial temporal artery (STA) to provide flow augmentation in a symptomatic 59-yr-old male with bilateral internal carotid artery occlusion at the origin, and left M1 segment occlusion. The patient suffered multiple left hemispheric strokes despite maximal medical therapy and was found to have poor hemodynamic reserve in the left hemisphere during evaluation with regional and global blood oxygenation level-dependent functional magnetic resonance imaging with CO2-challenge as well as quantitative magnetic resonance angiography and noninvasive optimal vessel analysis pre- and post-acetazolamide challenge. Postoperatively, the patient did very well and his hemodynamic studies improved significantly. The importance of this technique relies on the fact that we are using a single donor vessel to perform 2 anastomoses, and carries the following advantages: (1) the frontal STA branch remains intact and therefore can still be used at a later time if further revascularization is needed; (2) wound complications related to devascularizing the scalp from harvesting both STA branches are reduced; (3) 2 vascular territories are augmented (frontal and temporal) while using a single donor; (4) we are maximizing donor potential and optimizing cut flow index (CFI; total bypass flow postanastomosis divided by bypass cut flow) by flow augmenting 2 separate vascular beds therefore increasing demand. To explain that fourth point further: if the STA donor is able to carry a maximum 100 mL/min when cut, and after performing the first anastomosis bypass flow is only 37 mL/min, CFI will be 37/100 = 0.37, reflecting low demand, a poor indicator of graft patency, as previously published.1,2 By adding a second anastomosis which demands an additional 60 mL/min from the same STA donor, CFI (60 + 37)/100 improves to 1. Institutional Review Board approval was obtained for the review of patient chart and video files. Informed consent was obtained directly from the patient via telephone regarding use of media for educational and publication purposes 5).