In our study, we used the electrical database from Chengdu Women’s and Children’s Central hospital to identify risk factors for an unplanned reoperation following primary repair of gastrointestinal disorders in neonates. We found that the length of primary operative time was the independent risk factors for unplanned reoperation and patients with unplanned reoperation had a longer PLOS.
The importance of identification of risk factors
To our knowledge, serious postoperative complications, such as bleeding, intestinal obstruction, leakage, and infection, can lead to an unplanned reoperation. Unplanned reoperations are harmful to the patients due to repeated exposure to anesthetics and surgical pressure, especially in neonates with immature liver and kidney function. Furthermore, unplanned reoperation increases the family’s economic and psychological burden. Additionally, Ademuyiwa et al. has proved that reoperation was a significant determinant of mortality . Therefore, identification of risk factors in advance is essential to improve the quality of perioperative management and provide the evidence for medical decision-making.
The incidence of unplanned reoperation in neonates
In neonates, surgical intervention is required because of congenital malformation or acquired condition on gastrointestinal tract. Obviously, compared with adults or older children, neonates are at a higher risk due to the requirement for more delicate surgical techniques and poorer tolerance of surgical and anesthetic pressure. The incidence of unplanned reoperation varies greatly in different types of surgery. A retrospective study evaluated the unplanned reoperation rate following plastic surgery in pediatric patients and showed an overall rate of 0.8% (137/18106) within 30 days after surgery . However, 23.3% (10/43) patients required unplanned reoperation after primary repair for jejunoileal atresia . Theoretically, a more complex primary procedures is associated with an increased likelihood of a patient experiencing unplanned reoperation, as were the younger age. Unfortunately, there were few studies about the incidence of unplanned reoperation after gastrointestinal surgery in neonates. Studies in neonates were focused on relatively small series, most of which focus on a single procedure. Our study summarized a total of 296 newborns who underwent gastrointestinal surgery, including 11 types of surgical procedures, of which 254 (85.8%) underwent anoplasty or enterectomy. Only 1 patient (1/60, 1.7%) who underwent anoplasty experienced an unplanned reoperation, whereas 26 (26/194, 13.4%) patients who underwent enterectomy received reoperation. Totally, 9.8% neonates suffered unplanned reoperation, which was in line with previous reports.
Risk factors associated with unplanned reoperation
In theory, demographic characteristics, surgical services, and intraoperative features, as well as postoperative complications were all related to unplanned reoperation. In univariate analysis, anoplasty (OR 0.13; p = 0.04), enterectomy (OR 5.11; p < 0.01), duration of intraoperative hypothermia (OR 1.01; p = 0.01), and the length of operative time (OR 1.01; p < 0.01) were significantly associated with unplanned reoperation. However, our multivariate regression analyses identified that the only factor associated with unplanned reoperation was prolonged operative time, which was consistent with previous research . In plastic surgery, an association between increasing operative time and incidence of unplanned reoperation had been confirmed . And Sangal et al. had revealed that a greater total operation time was associated with an unplanned reoperation in major operations of the head and neck . These results could be interpreted as a more complex surgical procedure would be more likely to require unplanned reoperation. The prolonged operative time could be considered as a sign of procedure complexity. Reoperation resulted in a longer PLOS (Non-reoperation: 19.9 ± 14.7 days vs. Reoperation: 44.1 ± 32.1 days, p < 0.001). None of the remaining variables were significantly associated with unplanned reoperation in multivariate model, though some had been identified as risk factors in existing literature. A previous report which reviewed 9 nine-year experience in managing neonates with jejunoileal atresia presented that prematurity and low birth weight were associated with functional obstruction leading to reoperation . However, this conclusion was drawn from a relatively small sample size, including only 43 patients undergoing enterectomy, which reduced its credibility. With the development of neonatal care and the improvement of surgical skills in recent years, the premature neonates with low birth weight could be well treated, which might decrease the requirement of surgical intervention.
Although neither duration of hypothermia nor incidence of hypothermia were identified as risk factors in multivariant analysis, their potential effects should be taken seriously. Compared to patients without reoperation, patients with reoperation had a longer duration of hypothermia and higher incidence of hypothermia during initial surgical period. Intraoperative hypothermia might increase the risk of surgical site infection  and even death . The authors randomly assigned the patients to either normothermic or hypothermic group. They reported that surgical site infections were 19% of patients in hypothermic group and 6% of patients in the normothermic group (P = 0.009), and the length of hospitalization was extended by 2.6 days in the hypothermia group (P = 0.01) . We also demonstrated that PLOS was longer in patients with reoperation than those without reoperation. Those results could be interpreted as delayed healing because of wound infections. Additionally, a meta-analysis that included 48 studies had presented that most neonates with surgical site infection had gastrointestinal and/or colorectal surgery . Surgical site infection was associated with increased risk of unplanned reoperation in major head and neck surgery . Thus, we speculated that gastrointestinal surgery was associated with a high risk of unplanned secondary surgery. But in China, due to the disharmonious relationship between medical workers and patients, surgical site infection might not be recorded objectively. Therefore, limited in data collection restricted further analysis in current study.
The limitations in our study were as follows. First, although this cohort study was conducted in medical center which was the largest neonatal surgery center in western region of China, the sample size was still insufficient for further subgroup analysis. Second, the variation of surgeons’ expertise could not be well controlled, as the evaluation system of surgeons had not been fully established in our center. Next, gastrointestinal surgeries might be a consequence of patent ductus arteriosus (PDA) [20, 21]. The stealing blood flow from aorta to pulmonary arteries via PDA might exceed the physiological compensatory mechanisms, with a consequence of decreasing organ perfusion. The available literature has proved that prolonged ductal patency was associated with higher mortality rates and several adverse outcomes, including impaired renal function and necrotizing enterocolitis (NEC) . However, in our institutional database, the diagnoses, especially in emergency surgical patients, were not well-documented. Sometimes, only the diagnosis of surgical indications was recorded. Thus, it was difficult to consider PDA as a variable in the analysis, but it was an important factor that should be discussed. In the future, we will communicate with neonatologist and surgeons to improve the patient’s diagnosis record. Last, the number of variables assessed was very limited, especially variables related to baseline clinical condition and intraoperative course. There was a high risk of unexplored confounding factors. Yet, we believed that length of operation remained a good marker of a complex procedure due to either surgical or anesthesiologic factors.