The truth is that it depends entirely on the individual patient presentation. From a psychodynamic perspective, the motivation to seek surgeries can either be of a histrionic nature, that of "passive aggression" toward another in hopes of provoking guilt, and myriad other reasons.
The presentation may appear, as you say, as lying on the OCD spectrum, in which case, the treatment would be quite different...and different more still than that of a person exhibiting aneroid or other somatic delusions. Pharmacologically, the treatment options vary depending on the psychiatrists' assessment of the case, and the underlying drive of the pathological behavior. Again, it is invaluable to have medical school training when dealing with these folks, as they are unerringly somatic, will bombard you with complex disease state questions, and will "doctor shop" with the hopes of recruiting more and more sympathetic but misinformed surgeons to perform these procedures.