New Rule: Conflicting Expert Opinions on Standard of Care and Causation Create Triable Issues Precluding Summary Judgment in Medical Malpractice Actions

Introduction

Matney v. Boyle, 2025 NYSlipOp 02250 (App. Div. 3d Dep’t Apr. 17, 2025), arises from a complex postoperative injury following a laparoscopic sigmoid colectomy. Plaintiff Thomas R. Matney sued surgeon Sean P. Boyle (and his practice) for medical malpractice, claiming Boyle deviated from accepted standards of care, injuring Matney’s right ureter with a harmonic scalpel and failing to diagnose and treat that injury in a timely manner. Defendants moved for summary judgment, which the Supreme Court granted, dismissing plaintiffs’ complaint. On appeal, the Appellate Division reversed in part and held that competing expert affirmations on standard of care and causation created triable issues of fact, precluding summary judgment on the medical malpractice claims.

Key issues:

• Whether Boyle’s use of an electrosurgical harmonic scalpel breached the standard of care.
• Whether post‐operative delay in diagnosing a ureteral thermal injury constituted malpractice.
• Whether conflicting expert opinions on deviation and proximate cause defeat a summary judgment motion.

Parties:

• Plaintiffs/Appellants: Thomas R. Matney and spouse (derivatively).
• Defendants/Respondents: Sean P. Boyle (surgeon) and his practice.

Summary of the Judgment

The Appellate Division held that:

1. Defendants met their initial summary judgment burden by submitting the affirmation of surgeon Robert Raniolo, who opined Boyle’s technique fell within accepted practice, that the ureteral injury was a known risk of electrosurgery and that postoperative management complied with standards.
2. Plaintiffs then presented surgeon Roberto Bergamaschi’s affirmation, asserting Boyle deviated from the standard of care: he should have converted to open surgery for better visualization, consulted urology intraoperatively, and inspected/tested the ureters before concluding the procedure.
3. These competing expert opinions created triable issues of fact as to both deviation from the standard of care and proximate causation of Matney’s injury.
4. Accordingly, summary judgment dismissing the first (medical malpractice) and fourth (derivative) causes of action was improper and must be denied to that extent.

Analysis

Precedents Cited

The court’s decision closely follows New York’s summary judgment and medical malpractice caselaw:

• Young v. Sethi, 188 AD3d 1339 (3d Dep’t 2020), lv denied 37 NY3d 902 (2021): Plaintiff must prove deviation from accepted practice and causation.
• Launt v. Lopasic, 189 AD3d 1740 (3d Dep’t 2020): Defendants bear initial burden on summary judgment to show no deviation or no proximate cause.
• Kelly v. Herzog, 224 AD3d 1189 (3d Dep’t 2024): Once defendants meet their burden, plaintiffs must show specific expert proof of deviation and causation.
• Fischella v. Saint Luke’s Cornwall Hosp., 204 AD3d 1343 (3d Dep’t 2022): Conflicts in expert testimony generate triable issues.
• Henderson v. Takemoto, 223 AD3d 996 (3d Dep’t 2024): Courts must focus on “issue finding,” not determinations, on summary judgment.
• Hierro v. Bliss Co., 145 AD2d 731 (3d Dep’t 1988): Summary judgment is a drastic remedy and improper if any doubt exists regarding a triable fact.

Legal Reasoning

The Appellate Division applied the two‐step summary judgment framework for malpractice:

1. Defendants’ initial burden: Surgeons Raniolo’s affirmation established that Boyle’s conduct—use of the harmonic scalpel, hand‐assisted laparoscopic conversion, intraoperative ureter identification, and postoperative care—fell within the accepted standard of care and that any ureteral thermal injury was a known risk, breaking the causal chain (see Scott v. Santiago, 230 AD3d 933 [3d Dep’t 2024]; Busch v. Sherman, 209 AD3d 1230 [3d Dep’t 2022]).
2. Plaintiffs’ responsive burden: Bergamaschi’s affirmation directly challenged Raniolo’s conclusions, explaining that under proper technique thermal spread to a ureter is avoidable, that severe inflammation required open conversion or urology consult, and that inspection/testing of ureters was mandatory before closure. He linked the deviation proximately to Matney’s injury (see Kelly v. Herzog, 224 AD3d 1189; Fischella v. Saint Luke’s Cornwall Hosp., 204 AD3d 1343).

Because each side’s expert relied on record evidence and articulated reasoned analyses, the court deemed both affirmations substantive, creating triable disputes on (1) the applicable standard of care, (2) whether Boyle deviated from it, and (3) whether any deviation proximately caused the injury.

Impact

Matney v. Boyle clarifies that:

• Where experts squarely contest both standard of care and proximate cause—even on nuanced distinctions such as “direct” versus “delayed” thermal injury—summary judgment is inappropriate.
• The “issue‐finding” function of summary judgment demands only that conflicts exist, not their resolution (Henderson v. Takemoto; Hierro v. Bliss Co.).
• Surgeons must document intraoperative assessments (ureter visualization and testing) in inflammatory or high‐risk contexts to avoid later dispute.

Future malpractice motions in the Third Department must anticipate that any substantial expert conflict will likely defeat summary judgment, prolonging litigation to trial.

Complex Concepts Simplified

Harmonic Scalpel: An electrosurgical device using ultrasonic vibrations to cut and cauterize tissue. It poses a risk of thermal spread—heat radiates beyond the tip, potentially injuring adjacent structures such as ureters.
Direct vs. Delayed Thermal Injury:

• Direct: Immediate tissue damage when the device contacts the structure.
• Delayed: Heat damage appearing later as thermal energy dissipates through tissue.

Hand‐Assisted Laparoscopic Surgery: A hybrid approach where the surgeon’s hand assists instruments within a small incision. It may offer less visualization than open surgery when inflammation obscures anatomy.
Summary Judgment vs. Triable Issue: Summary judgment ends a case prior to trial if no factual disputes exist. A “triable issue” exists whenever reasonable minds could differ based on conflicting evidence, forcing a jury to decide.

Conclusion

Matney v. Boyle reinforces the principle that in medical malpractice litigation, summary judgment is appropriate only when expert proof is one‐sided. When plaintiffs and defendants each present credible, record‐based expert opinions on both breach of care and causation, those conflicts compel denial of summary judgment. This decision will guide surgeons to meticulously record intraoperative evaluations and caution litigators that nuanced disputes over surgical technique and injury timing necessitate jury resolution rather than pretrial dismissal.