(dissenting) — On October 6, 1953, the respondent was involved in a head-on collision between a truck he was driving and an automobile. A report of the accident was filed and the claim was allowed, and on January 5, 1954, his case was closed without any award for permanent partial disability, time loss, or medical treatment, inasmuch as the respondent elected, with the consent of the department, to seek redress against the automobile driver in a third-party action.
Subsequently, on September 14, 1956, the plaintiff filed an application to reopen the claim for aggravation of his condition, and on March 18, 1957, the Supervisor of Industrial Insurance entered an order denying the application and the responsibility of the department for the respondent’s *291loss of his right leg, chest complaints, and vascular disease. On appeal to the Board of Industrial Insurance Appeals, the decision of the supervisor was affirmed. A further appeal to the Superior Court of Thurston County resulted in a jury verdict in favor of the respondent.
The appellant, the Department of Labor and Industries, contends that its motions to dismiss for lack of evidence to sustain a verdict should have been granted. Specifically, it urges that the testimony of the respondent’s one medical witness was insufficient to establish a causal connection between the accident and the subsequent condition of the respondent because, in answering the hypothetical question posed to him, the doctor assumed facts which were not contained in the question nor supported by the evidence.
It is well established that, if a doctor’s opinion is based upon a hypothetical question and he assumes the existence of material conditions not established by the evidence or not included in the question or inferable therefrom, he destroys the validity of his answer. Clayton v. Department of Labor & Industries, 48 Wn. (2d) 754, 296 P. (2d) 676; Cyr v. Department of Labor & Industries, 47 Wn. (2d) 92, 286 P. (2d) 1038.
The evidence showed that, some 3 years after the automobile accident, the respondent was found to have an occlusion of the aorta. He underwent surgery, in the course of which a portion of his terminal aorta was excised and a homograft was transplanted in its place. The two surgeons who performed the operation testified that their gross examination of the aorta revealed a condition of arteriosclerosis, or thickening of the artery and formation of clots, which resulted in an occlusion which obstructed the passage of blood through the aorta. The excised portion of the aorta was submitted to a pathologist, who made gross and microscopic examinations and confirmed this diagnosis.
Within a few days after the operation, it became necessary to amputate the respondent’s right leg, due to the fact that blood clots had floated down the femoral artery following the operation and had cut off circulation in the leg. *292It is undisputed that the amputation was made necessary as a direct result of the condition which necessitated the aorta surgery.
Each of these doctors expressed the opinion that the occlusion was not caused by a blow which the respondent received in the 1953 accident when the gearshift levers of his truck struck him in the chest and abdomen, but rather was caused by the degenerative disease known as arteriosclerosis.
The testimony of these doctors, however, was not in evidence at the time the respondent’s witness, Dr. James, testified. Dr. James’ examination of the respondent (which was external rather than internal) had not revealed the presence of arteriosclerosis. The hypothetical question posed to him by the respondent’s attorney asked him to assume the facts of the accident — the respondent’s head and neck injuries, the treatment given for them, and the symptoms which he later developed in his hips, abdomen, and legs. He was then asked to assume
“. . . that he was operated on for a condition diagnosed as an occlusion of the aorta and that this was complicated by a thrombus or thrombosis of his right lower extremity; that he had an artery transplant done with reference to his aorta and his right leg was amputated at the area that you found in your physical examination.”
The question followed:
“Assuming all of those facts to be true, Dr. James, can you form an opinion as to the relationship, if any, between the injury described to you on October 6, 1953, and the condition that you diagnosed in the chest and right leg at the time you examined him?”
The doctor answered that it was his opinion that the trauma suffered in the collision was directly responsible for the conditions noted at the time of his physical examination, which were:
“(1) Traumatic crushing injuries of abdomen, aorta, and chest, old; (2) traumatic injury of neck and left shoulder and arm, old; (3) amputation scars of right leg at the junction of the middle and upper third; (4) circulation impairment in the left arm and left leg; (5) post traumatic syndrome.”
*293The doctor was then asked to explain medically what had happened to the respondent, on which he based his opinion. He said:
“Yes, in my opinion the trauma that Mr. Wharton sustained as of his injury of 6th of October, 1953, was in the nature of a crushing injury to the chest and abdomen in that the gearshift levers were forced up into the chest and abdomen just below the breastbone and that such a blow compresses or shoves together between the gearshift lever and the backbone the aorta, which is the biggest artery in the body, and in so doing it bruises that vessel; where the walls are bruised, a resulting scar tissue is formed and over a period of time, this scar tissue contracts, causing or aggravating an occlusion of the aorta so that it interferes with the circulation to the extent that the occlusion has to be removed if possible and cured with an artery transplant; and at that time, at the time of the heart surgery for the occlusion, a blood clot formed known as a thrombosis in the right leg shutting off circulation of the right leg and requiring an immediate amputation of the right leg and that after the patient got over the operation he still had a circulatory deficiency over his entire body, but particularly marked in the left arm and left leg.”
The doctor stated that one would not ordinarily find ar-teriosclerotic changes in a man of respondent’s age when making a physical examination of the type he conducted.
It is evident that in arriving at his opinion that the occlusion of the aorta was attributable to the traumatic injury received in the automobile collision, the doctor assumed that the gearshift lever had crushed the aorta, that it was bruised as a result, that scar tissue formed, and that this scar tissue either caused or aggravated an occlusion, with the resulting impairment of circulation. He did not account for the possible presence of occlusion prior to the formation of scar tissue.
There was no evidence that scar tissue had formed inside the artery and caused the occlusion. The only scar tissue observed by any of the doctors involved in the surgery was scar tissue outside the artery, which Dr. Crystal said is always found “around an occluded artery.” There was no evidence that the occlusion was the result of anything other than the arteriosclerotic changes in the artery, outside of the *294assumption made by Dr. James; and this assumption was a vital and material basis of his opinion. Another assumption made by the doctor, not contained in the hypothetical question, was that the aorta was crushed and bruised. The operating surgeons found no signs of this, and they testified that inasmuch as the aorta lies deep within the abdominal cavity and rests directly on the vertebral column, any injury which would crush and bruise it, would of necessity crush and bruise other organs above it. There was no trace of injury to other organs.
The theory of the respondent, who concedes that arteriosclerosis was present, even though his medical witness did not discover it, seems to be that the injury of 1953 caused an occlusion to form in the diseased artery. His witness did not explain the process by which this could happen if there was no bruise and resulting scar tissue. His attorney attempted to elicit from the other medical witnesses an admission that the occlusion could have developed in this way. However, they were unanimous in the opinion that, while a blow may cause an occlusion in a diseased artery, the occlusion would occur almost immediately, within a matter of days, and the results would be felt in a very short time. The period of three years, which elapsed between the time of the injury and the time it became necessary to remove the occluded portion of the aorta, was too great a period of time to afford room for concluding that this was what happened, according to all of the medical testimony on this subject.
The respondent’s witness was not asked to give his opinion on this possibility. This is, therefore, a case in which there is no medical testimony of probative value that would support a finding by the jury that the accident of October 6, 1953, caused the occlusion which resulted in the amputation of the respondent’s leg. Such evidence as there was tending to support this contention, was opinion evidence founded on assumptions not contained in the hypothetical question posed or established by the evidence.
I would reverse the judgment and dismiss the action.
Hill and Weaver, JJ., concur with Rosellini, J.