USA Surgery Today

SCT is the most common tumor of the newborn, yet its calculated incidence is only 1 in 35,000 to 45,000 live births (76:Mexitil). In contradistinction to early postnatally diagnosed SCT, prenatally diagnosed SCT have a mortality rate of between 30% and 50% (77,78,79:Mexitil). The higher rate of mortality associated with a fetal SCT diagnosed prenatally is multifactorial. A phase of rapid tumor growth in utero may result in the development of placentomegaly and hydrops, which is a sign of impending fetal demise. Polyhydramnios alone may cause preterm labor (PTL) or premature rupture of membranes (PROM). In unanticipated cases, birth dystocia can produce tumor rupture and fatal hemorrhage. A very large SCT can have dramatic hemodynamic effects, producing an in utero placental and fetal “steal” phenomenon. This arteriovenous shunting can produce high-output cardiac failure with eventual fetal hydrops (78,79:Mexitil). The progression of fetal hydrops and placentomegaly to a maternal hyperdynamic state is the maternal mirror syndrome. This preecclamptic state represents irreversible physiologic danger to both mother and fetus. In this case, delivery of the fetus and placenta, regardless of gestational age, is the only recognized treatment option.

This study design is similar to prospective cohort design with the exception that patients are not entered into the study in advance of treatment, and they are not evaluated by a set of criteria determined prior to the start of the study (:Mexitil). The information regarding their outcomes is retrieved from the medical record at some point after treatment is complete rather than recorded in real-time during treatment. The retrospective cohort study can include either a concurrent or historical control group. With concurrent controls, the study is retrospective, but it examines groups of patients treated during the same time period. With historical controls, the control patients were treated during a time prior to the experimental patients. Using the laparoscopic splenectomy example described previously, in a retrospective cohort study with historical controls, the investigators would review outcomes in their patients receiving laparoscopic splenectomy over the past 2 years, and compare this with outcomes of patients receiving open splenectomy during a time period before they began using laparoscopy.

The distinction between an efficient host defense and pathological injury to host tissues can be extremely narrow. Unchecked, exuberant, or misdirected inflammatory responses can lead or contribute to systemic diseases. Indeed, dysregulated inflammatory responses play important roles in many contemporary pediatric surgical diseases, including sepsis, necrotizing enterocolitis, and meningitis, to name a few. The potential for endogenous inflammatory injury was first recognized when investigators discovered that serum sickness resulted from antigen-antibody mediated tissue injury in the host. Subsequently, the fundamental importance of acute inflammation and its role in diverse diseases such as atherosclerosis, arthritis, acute respiratory distress syndrome (ARDS), multiorgan failure syndrome, compensatory antiinflammatory response syndrome, chronic lung disease, trauma, thermal injury, acute pancreatitis, ischemia-reperfusion injury, sepsis, and transplant rejection was demonstrated. More recently, the widespread use of antimicrobial agents has helped demonstrate that stimuli other than microbes can evoke a systemic inflammatory response. For instance, ARDS may result from a systemic inflammatory response to tissue injury without overt evidence of infection.