dissenting.
[¶ 20] In reaching its decision, the district court found appellees had presented a prima facie case for summary judgment irrespective of the affidavit of appellees' medical expert, Dr. Richard Hughes, by demonstrating McMackin's failure to show that any treatment would have altered the death of Ms. Brown. The district court also ruled that McMackin had failed to present competent evidence that any treatment more likely than not would have prevented the massive hemorrhage in Ms. Brown's brain, which resulted in her death. Therefore, the district court determined that no genuine issue of material fact remained on the issue of causation and appellees were entitled to summary judgment.
[¶ 21] In a medical malpractice action the plaintiff is required to prove that failure to perform a required duty proximately caused the damages alleged by the plaintiff. Fiedler v. Steger, 713 P.2d 773, 775 (Wyo.1986) (citing Vassos v. Roussalis, 625 P.2d 768, 772 (Wyo.1981)). Proximate cause means that the accident or injury must be the natural and probable consequence of the act of negligence. Fiedler v. Steger, at TIS (citing McClellan v. Tottenhoff, 666 P.2d 408, 414 (Wyo.1983) and Harris v. Grizzle, 625 P.2d 747, 758 (Wyo.1981)). The establishment of the element of proximate cause is normally a question of fact for the jury unless the evidence is such that reasonable minds could not disagree wherein such issue becomes a matter of law. Stephenson v. Pacific Power & Light Co., 779 P.2d 1169, 1178 (Wyo.1989); Kopriva v. Union Pacific Railroad Co., 592 P.2d 711, 718 (Wyo.1979).
[¶ 22] Wyoming Rules of Civil Procedure 56(e) further requires that both supporting and opposing affidavits with respect to motions for summary judgment be made on personal knowledge, set forth such facts as would be admissible in evidence, and show affirmatively that the affiant is competent to testify to the matters stated therein. Moreover, after the movant makes a prima facie showing that there are no issues of material fact involved and that an inquiry into the facts is unnecessary to clarify the applicable law, the burden of proof shifts to the opposing party who must show a genuine issue of material fact or come forward with competent evidence of specific facts countering the facts presented by the movant. The burden is on the nonmoving party to show specific facts as opposed to general allegations. The material presented must be admissible at trial. Conclusory statements are inadmissible. Mercado v. Trujillo, 980 P.2d 824, 825-26 (Wyo.1999) (citing Nowotny v. L & B Contract Industries, 938 P.2d 452, 455 (Wyo. 1997) and Thomas by Thomas v. South Cheyenne Water and Sewer Dist., 702 P.2d 13038, 1304 (Wyo.1985)).
When the party moving for summary judgment has established a prima facie case, the burden of production shifts to the opposing party who then is obliged to marshal admissible evidence, as opposed to general or conclusory allegations, establishing continuing viability of an issue of material fact. Such evidence must be competent and admissible, lest the rule permitting summary judgments be entirely eviscerated by plaintiffs proceeding to trial on the basis of mere conjecture or wishful speculation.
Campbell ex. rel Campbell v. Studer, Inc., 970 P.2d 389, 392 (Wyo.1998) (emphasis added) (quoting Estate of Coleman v. Casper Concrete Co., 989 P.2d 288, 286 (Wyo.1997)). See also Mize v. North Big Horn Hosp. Dist., 931 P.2d 229, 288 (Wyo.1997) Harris v. Grizzle, 625 P.2d at 751 and 758.
[¶ 23] In support of their motions for summary judgment, appellees tendered the pleadings of record; the deposition tran-seripts of Dr. Kirven, Dr. Schueler, Jennifer Sather, R.N., Dr. Cutehall, and Diana Ward Collins, R.N.; the initial report issued by Dr. Cutchall; and the affidavit of Dr. Hughes. Review of Dr. Kirven's deposition transeript *1102evidences that he did not believe any treatment could have been given to Ms. Brown that would have been of assistance to her when he was contacted on March 8, 1999, at approximately 4:80 a.m. Dr. Kirven also indicated that, given Ms. Brown's medical history, administering treatment to her prior to that time on March 7 or 8, 1999, would have proven unsuccessful. Similarly, Dr. Schueler testified in his deposition that, given Ms. Brown's medical history and the fact that she had either experienced a stroke or a hemorrhage in her brain as of the morning of March 8, 1999, no treatment given to her earlier on March 7 or 8, 1999, would have mitigated her injury. These doctors also generally testified that the medical treatment they each rendered to Ms. Brown from July of 1998 until March 7, 1999, was appropriate given the specific situation and cireumstances experienced by Ms. Brown.1
[T24]) Dr. Cutchall, a family practitioner, through McMackin's supplemental designation of expert witnesses and her own deposition, stated that Ms. Brown died from complications of a hemorrhagic stroke preceded by untreated TIAs and attributed the death of Ms. Brown to the negligence of each of the appellees. Dr. Cutchall, in her deposition, however, goes on to merely theorize that an ischemic/embolic/thrombotie stroke2 may precede and be the cause of a hemorrhage and that she suspected that this was what occurred with Ms. Brown. In fact, she admitted that in the vast majority of cases, hemorrhagic strokes,3 like those suffered by Ms. Brown, are unrelated to embolic strokes, and no medical literature exists that establishes a connection between the two.
[¶ 25] Specifically, Dr. Cutchall stated her theory was that Ms. Brown had recurring TIAs that were not treated, resulting in an embolic stroke which may have caused the hemorrhagic stroke. However, she stated that one cannot distinguish between an em-bolic stroke and a hemorrhagic stroke with a clinical examination and the only way to distinguish between the two is with a CT sean. Dr. Cutchall further admitted that the CT sean performed upon Ms. Brown did not reveal an embolic stroke that she testified may have occurred but revealed only a hemorrhagic stroke caused by a massive hemorrhage. Finally, Dr. Cutchall admitted that absolutely no evidence existed in this case that would establish that Ms. Brown had previously suffered from an embolic stroke, a crucial part of her theorized expert opinion.
[¶ 26] Dr. Cutchall also confirmed that Ms. Brown could have simply had a spontaneous bleed. She further advised that she could not testify to a reasonable degree of medical probability that the massive hemorrhage had not been present since the onset of Ms. Brown's TIA symptoms. Dr. Cutchall also admitted that, while TIAs may be a *1103predictor of an embolic stroke, TIAs are not a predictor of a hemorrhagic stroke, the condition that caused Ms. Brown's death. In addition, Dr. Cutchall affirmed that it is often common, even after a full neurological workup is performed on a patient experiencing TIAs, for the specific etiology of the TIAs to remain undetermined.
[T27] Based upon her assumption that Ms. Brown may have had an embolic stroke preceding the hemorrhagic stroke, Dr. Cute-hall proffered various treatments that could have been ordered for Ms. Brown before the massive hemorrhage. However, Dr. Cutchall and the other medical experts stated that no known treatment would have prevented the cerebral hemorrhage which took Ms. Brown's life. Further, there is primarily no treatment for a cerebral hemorrhage after it occurs other than comfort and care. Critically, Dr. Cutchall also stated that she did not personally review the CT sean taken of Ms. Brown but only reviewed the CT sean reports as a basis for her opinion. She further stated that she did not hold herself out as a neurologist and that a neurologist would have a much better opinion of the cause and possible treatment of Ms. Brown's massive cerebral hemorrhage due to a neurologist's more specific expertise in the area.
[¶ 28] In his affidavit submitted by appel-lees in support of their motions for summary judgment, Dr. Hughes, a neurologist, opined based upon a reasonable degree of medical probability that Ms. Brown's history was consistent with a condition known as amyloid angiopathy, which is a well documented condition related to aging that causes a crystal-like substance to form in the arteries of the brain.4 This condition is often preceded by multiple episodes clinically indistinguishable from TlAs. The artery eventually breaks in the periphery, causing a hemorrhage. Dr. Hughes also stated that Ms. Brown's medical history evidenced that she had previously suffered from white matter disease, which was consistent with a hemorrhage secondary to amyloid angiopathy. Moreover, amyloid angiopathy is normally diagnosed only after there has been a hemorrhage, and there is no treatment other than blood pressure monitoring, which was performed in this case.
[¶ 29] Alternatively, Dr. Hughes suggested that an artery in Ms. Brown's brain may have became blocked or occluded, and the resulting pressure caused it to rupture and hemorrhage. However, Dr. Hughes stated that this scenario was unlikely since Ms. Brown experienced a large cerebral bleed as demonstrated by the CT sean, hemorrhages caused by a prior embolism normally do not result in as much bleeding, and only 1 out of 200 hemorrhages is the result of a prior embolism. Therefore, Dr. Hughes concluded that the cerebral hemorrhage suffered by Ms. Brown was not preceded by or caused by an embolic stroke. Dr. Hughes also attested that a hemorrhage can result from hypertension; but this was unlikely in Ms. Brown's case since bleeding caused by hypertension is usually deep within the brain, and Ms. Brown's bleeding occurred on the periphery as shown by the CT sean. Therefore, Dr. Hughes concluded that the probable cause of the cerebral hemorrhage incurred by Ms. Brown was amyloid angiopathy. He also stated that there was no treatment that would have prevented or altered the cerebral hemorrhage suffered by Ms. Brown regardless of which of the three events he referred to had caused that hemorrhage.
[¶ 30] Further, Dr. Hughes stated that if medications were given to Ms. Brown to prevent stroke, it would have likely precipitated a bleed and Ms. Brown would have died even earlier. Finally, Dr. Hughes opined that, even if Ms. Brown had been treated by a neurologist who was aware of an impending stroke, the outcome would have been no different. (Id.)
[¶ 31] Accordingly, given my independent review of the record, I agree with the district court's determination that appellees present*1104ed adequate evidence, even outside consideration of the substantial affidavit submitted by Dr. Hughes, to make a prima facie showing that no genuine issue of material fact existed as to the issue of causation. Upon consideration of the affidavit of Dr. Hughes, the district court's conclusion is certainly even more supported. Therefore, I would hold that the district court did not err in its determination that appellees had presented adequate evidence to make a prima facie showing for the granting of summary judgment.
[¶ 32] As indicated above, after the mov-ant makes a prima facie showing that there are no issues of material fact involved and that an inquiry into the facts is unnecessary to clarify the applicable law, the burden of proof shifts to the opposing party who must show a genuine issue of material fact or come forward with competent evidence of specific facts countering the facts presented by the movant. However, review of the testimony of Dr. Cutchall noted in detail above evidences her opinion concerning causation is conjectural at best, and a more thorough review of her total testimony evidences that her opinion as to causation is merely speculative. Indeed, when asked the specific basis for her opinion concerning causation, Dr. Cutchall admitted that the foundation leading her to this conclusion was simply her own personal patient history. Dr. Cutehall could not give any scientifically based detailed analysis.
[¶ 33] Dr. Mitchell Felder's affidavit was also proffered in opposition to the summary judgment motions. Dr. Felder, a neurologist, stated through an opinion letter attached to his affidavit, that the cause of Ms. Brown's death was a massive hemorrhage which was preceded by untreated TIlAs. He offered several possible alternatives as to the cause of the fatal hemorrhage but did not conclude which of them was its probable cause. He also, like Dr. Cutchall, describes theoretical treatments that could have been given to Ms. Brown concerning the TIAs she was experiencing. However, Dr. Felder did not state that these treatments would have in any way prevented the massive hemorrhage that Ms. Brown experienced. Again, the statements of Dr. Felder are solely concluso-ry and, as such, fall short of establishing a material question of fact with respect to causation.
[¶ 34] The principles adopted by this court in Weber v. McCoy, 950 P.2d 548 (Wyo.1997) and Vassos v. Roussalis, 658 P.2d 1284 (Wyo.1983) make it clear that medical experts need not assert their opinions through utilization of specific terms to be valid. However, the expert opinion rendered must be based in fact and on an adequate foundation. Expert opinion cannot be based on mere inferences, conclusions, and assertions, as such opinion is mot sufficient to defeat summary judgment. Garnett v. Coyle, 2001 WY 94, 113-6, 33 P.3d 114, 113-6 (citing McClellan v. Britain, 826 P2d 245, 247 (Wyo.1992); Mayflower Restaurant Co. v. Griego, ""Al P.2d 1106, 1113 (Wyo.1987); Stundon v. Sterling, 736 P.2d 817, 318 (Wyo. 1987)); Blackmore v. Davis Oil Co., 671 P.2d 834, 336-87 (Wyo.1983) (quoting Gennings v. First Nat'l Bank at Thermopolis, 654 P.2d 154, 155 (Wyo.1982)).
[¶ 35] Certainly, while both experts proffered by McMackin testified that Ms. Brown died of a cerebral hemorrhage in her brain that was preceded by untreated TIAs, neither could sufficiently draw any further specific conclusion regarding the cause of her death and that appellees' actions contributed to her death. Simply put, in this case an essential element, the causal connection between the alleged breach of a duty owed and the injury sustained, is missing.
[¶ 36] Furthermore, when reviewing expert testimony, a trial court is required to act as a "gatekeeper" to determine the reliability of the proffered expert testimony by applying the flexible criteria set forth in our opinion in Bunting v. Jamieson, 984 P.2d 467, 471-73 (Wyo.1999) (formally adopting in Wyoming the four non-exclusive tests to the facts at hand enunciated in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 592-94, 118 S.Ct. 2786, 2796-97, 125 L,Ed.2d 469 (1998)). A trial court must be given broad latitude in determining whether expert testimony is based upon reliable scientific methodology so as to make the conclusions offered by an expert admissible. Thus, *1105our scope in reviewing such issues is very narrow-reversing the trial court's decision only if we conclude that it abused its discretion in excluding expert testimony. Hollander v. Sandoz Pharmaceuticals Corp., 289 F.3d 1193, 1206-07 (10 Cir.2002).
[¶ 37] As indicated above, the district court was presented with voluminous materials to assist it in its ruling on the motions for summary judgment and ultimately applied the Daubert principles before rendering its decision. Upon review of the district court's analysis, I cannot conclude that the district court clearly abused its discretion in rendering its decision. To the contrary, the district court, based on the specific materials provided to it, reasonably determined that the evidence presented was insufficient to scientifically establish that a cause-effect connection existed in this case. Therefore, I concur with the conclusion reached by the district court that McMackin failed to present competent and admissible evidence that any treatment more likely than not would have prevented the massive hemorrhage in Ms. Brown's brain, which resulted in her death.
[¶ 38] The majority bases its reasoning on the "loss of chance" doctrine. Nevertheless, the application of that doctrine does not obviate the mandate that a plaintiff must show by competent and admissible evidence the causal connection between the defendant's omission and the damage allegedly suffered. I agree that expert testimony must be based on reliable methodology, but need not be so persuasive as to meet the proponent's ultimate burden of proof, and that if the admissibility bar is raised too high, the court usurps the jury's duty to evaluate the expert's credibility and weigh the evidence. See Bunting, 984 P.2d at 473 and Heller v. Shaw Industries, Inc., 167 F.8d 146, 156 (39 Cir1999). However, this did not occur in this instance because MceMackin failed to present any expert opinion based on reliable scientific foundation.
[¶ 39] I would, therefore, affirm the ruling of the district court granting summary judgment in favor of appellees.
. Ms. Sather's deposition transcript simply evidences her recollection of what had occurred during the evening of March 7, 1999, and the morning of March 8, 1999, concerning the nursing care Ms. Brown received. Specific issues concerning causation were not addressed through this deposition.
In similar fashion, the deposition transcript of Ms. Ward-Collins, the nursing expert designated by McMackin, deals almost exclusively with the subject of standard of care as it relates to nursing, and no issues regarding causation were addressed through this deposition. However, it is interesting to note that Ms. Ward-Collins testified that Vicki Blakely, LP.N. met the standard of care for nurses regarding the nursing care she rendered to Ms. Brown on the morning of March 8, 1999.
. - "Embolic" is defined as "[rlelating to an embo-lus or to an embolism." "Embolism" is defined as an "[olbstruction or occlusion of a vessel by an embolus." "Embolus" is defined as "[a] plug, composed of a detached thrombus or vegetation, mass of bacteria or other foreign body, occluding a vessel." - "Thrombotic" is defined as "[rlelating to, caused by, or characterized by thrombosis," while "thrombosus" is defined as "[flormation or presence of a thrombus; clotting within a blood 'vessel which may cause infarction of tissues supplied by the vessel." "Thrombus" is defined as [al clot in the cardiovascular systems formed during life from constituents of blood; it may be occlusive or attached to the vessel or heart wall without obstructing the lumen." See Steadman's Medical Dictionary, 25th Edition Illustrated (1990).
For ease of reference an ischemic/embolic/thrombotic stroke will be simply referred to as an embolic stroke.
. "Hemorrhagic is defined as "[rlelating to or marked by hemorrhage." "Hemorrhage" is defined as "[hJemorrhea; bleeding; an escape of blood through the ruptured or unruptured vessel walls" or "[to bleed." See Steadman's Medical Dictionary, 25th Edition Hlustrated (1990).
. - It is recognized that the district court expressly did not rely upon the affidavit of Dr. Hughes in making its determination that appellees had established a prima facie case for the granting of summary judgment. However, it is well established that this court may affirm a district court's grant of summary judgment under any proper legal theory on the record presented. Vernon T. Delgado Family Ltd. Partnership v. Shaw, 9 P.3d 982, 983 (Wyo.2000) (quoting Hulse v. First Interstate Bank of Commerce-Gillette, 994 P.2d 957, 958-59 (Wyo.2000)).