Marsh’s observation that “the value of my work is measured solely in the value of other people’s lives” (43) emphasizes the centrality of his patients to the memoir. The case studies in Do No Harm collectively create a composite portrait of the moral and clinical landscape he navigates as a neurosurgeon. Taken together, they illustrate the memoir’s central concerns: the instability of surgical outcomes, the ethical ambiguity of intervention, the persistence of hope, and the emotional cost of medical responsibility.

Melanie and Will represent the rare instances of the surgical “triumphs” that sustain Marsh as a practitioner. Melanie’s restored sight alongside the safe delivery of her child, and Will’s survival after a near-catastrophic operation, illustrate the life-altering potential of neurosurgery. Yet even these apparent triumphs are shadowed by risk and contingency. Will survives despite Marsh’s surgical mistake that leads to uncontrolled bleeding, and Melanie’s recovery is initially uncertain. These cases reinforce the idea that success in surgery is often precarious, dependent on variables beyond the surgeon’s full command.

In contrast, Helen and David foreground the limits and the ethics of surgical intervention. Both patients suffer from progressive, ultimately fatal conditions, yet their trajectories diverge in ways that expose the complexity of clinical judgment. With David, Marsh exercises restraint, refusing further surgery and prioritizing his patient’s dignity over the futile extension of life. The neurosurgeon’s final emotional encounter with David underscores the difficulty of withdrawing treatment and Marsh’s inevitable bond with patients he has treated for many years. Conversely, Helen’s case reveals the consequences of yielding to false hope. Despite recognizing the operation’s futility, Marsh cedes to the family’s pressure to potentially extend Helen’s life. Afterward, Marsh's unwillingness to look at the bandages covering Helen’s infected wound represents remorse and a reluctance to confront the breach of his own integrity. Together, these cases illustrate the memoir’s concern with the tension between prolonging life and preserving its quality.

In Marsh’s portrayal of his patients, the influence of hope emerges as a defining force. Patients and families often cling to the possibility of recovery, even when medical evidence suggests otherwise. The memoir portrays this hope as both necessary and potentially harmful: It can sustain patients through suffering, yet also drive decisions that lead to further harm or disappointment. Collectively, these patients also highlight the emotional and psychological demands placed on the clinician. Marsh’s responses, ranging from elation to regret and grief, demonstrate that professional responsibility extends beyond technical performance to include enduring the human consequences of each decision.

Igor Kurilets is a Kyiv-based Ukrainian neurosurgeon who becomes Henry Marsh’s clinical partner and collaborator. Working within the challenging context of a post-Soviet health system plagued by equipment shortages, corruption, and rigid hierarchies, Kurilets embodies the spirit of pragmatic reform and ethical courage. He is the on-the-ground agent of change, striving to modernize local neurosurgical practice despite significant institutional resistance. For Marsh, Kurilets represents clinical realism and relentless initiative in the face of overwhelming constraints.

Kurilets’s contribution is central to the book’s chapters on Ukraine. Beginning as a junior doctor, he becomes a formidable surgeon in his own right, founding the International Neurosurgery Centre in Kyiv and driving the selection of high-risk cases that he and Marsh tackle together. He provides the essential local knowledge, patient relationships, and relentless drive that make Marsh’s visiting efforts clinically meaningful. Their partnership, depicted in the documentary The English Surgeon and in Marsh’s narrative, is one of mutual respect and candid dialogue, shaping the judgment and ethical perspectives of both doctors.

Through Kurilets’s experiences, Marsh illustrates the systemic barriers to progress in a system inherited from the Soviet era. Kurilets faces denunciations and professional turf battles from an entrenched medical establishment that prioritizes reputation over patient outcomes. His struggle highlights the moral courage required to push for modernization and ethical standards against a backdrop of bureaucratic inertia. He is a vital figure who grounds Marsh’s philosophical reflections in the harsh realities of a health system in transition, serving as a model of resilience and professional integrity.

Andrii Romodanov was a Ukrainian neurosurgeon and the long-time director of the Kyiv Research Institute of Neurosurgery. In Do No Harm, he functions as a symbol of the Soviet and early post-Soviet medical establishment. When Henry Marsh first visits Ukraine in 1992, Romodanov represents the official, hierarchical, and deeply entrenched old guard of the nation’s neurosurgical tradition. His imposing stature provides the institutional backdrop against which the reformist efforts of Marsh and Igor Kurilets unfold.

Romodanov’s role is primarily contextual. Marsh uses his encounter with him to highlight the dissonance between the official grandeur of Soviet medicine and the grim, under-resourced reality of its clinical practice. Although the institute was a national hub and later renamed in his honor, Marsh’s narrative implies that its reputation masked significant deficiencies. This contrast between appearance and reality is what motivates the collaborative and critical work that Marsh undertakes with Kurilets, positioning their partnership as a necessary challenge to an outdated and ineffective system.