4. Discussion
Apart from feeding, PEG may also be used as part of a curative approach in individuals with severe PD and motor fluctuations, where dopamine precursors (levodopa–carbidopa gel) are administered through a jejunal extension tube directly to the jejunum—JET-PEG. Several previous studies report a relatively high frequency of complications related to JET-PEG, with incidence of complications up to 76%, and 17% of them reported as serious. Most commonly, these complications occurred during PEG insertion (41%) and abdominal pain was noted in 36% of patients [
10,
12]. Here we present the first study to directly compare the incidence and characteristics of early-, late-onset, and technical complications in subjects with N-PEG compared to JET-PEG.
In our study, early and technical complications were significantly more common among JET-PEG patients with advanced PD (70% JET-PEG vs. 10% of N-PEG). One JET-PEG patient experienced extensive pneumoperitoneum; in her case, PEG insertion led to a partial rupture of the stomach at the site of PEG insertion and required surgical intervention with PEG withdrawal and suture of the perforated stomach. Her BMI at the time of PEG insertion was 18, therefore severe malnutrition could be a precipitating factor for such an adverse event. Intestinal or stomach lacerations occur rarely with 0.5–1.3% incidence among complications associated with PEG. Pih GY et al. [
13] mentioned developing of pneumoperitoneum in 9.5% within the first week of PEG placement. A small portion of patients had peritoneal irritation. All patients showed improvement with conservative management [
13]. Results of the retrospective multicenter study found that age, diabetes, heart failure, higher CRP, and lower BMI all impact the risk of adverse outcomes (mortality and complications within 30 days) of PEG patients [
5].
In the literature, the cause of pneumoperitoneum in PEG patients is thought to be air leakage during endoscopic insufflation of the stomach, and is a quite common and generally benign complication occurring in 4.7–57% of all cases [
14,
15] within three hours after PEG tube placement. Late pneumoperitoneum, three weeks after N-PEG insertion has been rarely reported [
16,
17,
18].
Compared to previous reports that have individually assessed JET-PEG [
19,
20,
21,
22] or N-PEG [
23,
24] cohorts, we have also observed similar rates of late complications including stoma granulomas, infection, leaking, and painful purulent secretion. In our study, the incidence of technical complications related to the PEG and jejunal tube was high in the JET-PEG group including J-tube malfunction (caused by accidental cutting or extraction), obstruction and leaking of the tube, and tube kinging or dislocation. These complications do not occur in the N-PEG group because patients have only a gastric tube, with technical complications only 5.1%
The most common complication among our JET-PEG group was pain requiring repeated analgesic administration. All subjects with JET-PEG were fully conscious and mobile during PEG insertion compared to N-PEG individuals where only 20% were fully mobile. We suppose that hyperkinetic syndrome, especially the presence of levodopa-induced dyskinesia, in conscious PD individuals increases the painfulness due to hypermobility of the PEG catheter in the stoma with local peritoneal irritation for a few days after PEG insertion until full maturation of the gastrostomy canal Another cause of the increased prevalence of early pain in conscious PD patients may be related to noncompliance to diet regimens, e.g., eating an orange or other solid food despite instructions on the day of JET-PEG placement, which were repeatedly observed mostly in subjects with PD and cognitive decline. Similar to JET-PEG, pain was previously reported as the most common complication after PEG insertion for nutritional purposes, with an incidence of 9.2% during the first 30 days and 14.4 in the first year [
24]. According to Epstein et al. [
25]. procedural and abdominal pain are not commonly noted in the gastrointestinal literature because these events are expected as a consequence of the endoscopic procedure, which requires percutaneous abdominal wall puncture for PEG-J placement. In one study, rates of abdominal pain were 13% at 2 weeks post-procedure and 4% at 8 weeks [
26].
In terms of the occurrence of complications depending on PEG handling, all three types of complications seemed to be more frequent in subjects who cared for PEG by themselves and/or the PEG was cared for by a family member in contrast to those in whom the PEG was handled by a healthcare professional, although this association was not confirmed in logistic regression analysis. However, proper PEG handling is vital for its functioning and prevention of complications. The position of patients during PEG insertion (supine vs. left flank position) affected the number of early and technical complications. Changing the supine position to the left flank after PEG insertion is due to better positioning of the jejunal to the deep duodenum. We hypothesize that positioning the patient with a freshly punctured stomach wall may cause leakage of gastric fluid and insufflated air into the peritoneum, with a higher risk of complications.
The most common medical complications in JET-PEG individuals were infection and granuloma. Interestingly, in a significant proportion of subjects presenting with these complications, we have observed that the external binder was not kept 1 cm away from the abdominal skin, as instructed during initial pump training, but was rather loose or cut off completely by the patient, allowing the tube to move extensively within the abdominal wall. Thus, adequate training and retraining seem to be of high priority to prevent these kinds of complications in JET-PEG patients. In our cohort, we did not observe buried bumper syndrome in JET-PEG individuals, which can be explained by a frequent manipulation of the stoma catheter in combination with regular tube rotation that may prevent mucosal overgrowth and prevent buried bumper syndrome.
WBC and CRP levels at the time of PEG insertion were significantly higher in the N-PEG group compared to the JET-PEG group N-PEG subjects were commonly intensive care unit patients with severe comorbidities including malignancies that led to the significant difference in the levels of inflammatory markers. In individuals with increasing CRP levels, abdominalgia was present but the clinical presentation of peritonitis was not observed. CRP elevation after PEG insertion is an expected phenomenon, because perforation of the stomach is followed by minimal gastric leaking. In the literature, the procedural incidence of peritonitis was 0.5–1.5% [
25,
27]. Peritonitis immediately after the procedure usually indicates damage to the viscus or leakage of gastric contents into the peritoneum. Peritonitis, diagnosed clinically, is not based on the presence of abnormal bacterial cultures, and may be due to early post-operative “in-and-out” movement of the PEG J-tube [
25]. In our PD cohort, individuals undergoing JET-PEG insertion are fully mobile shortly after the procedure, which promotes minimal leakage of air and gastric juices with subsequent peritoneal irritation and CRP elevation. One female with JET-PEG experienced diffuse peritonitis despite antibiotic prophylaxis, and her CRP reached 289.2 mg/l. In this case, subsequent antibiotic therapy was effective, and her PEG could be preserved. This complication was probably related to malnutrition and hypoalbuminemia, which are well-recognized risk factors for higher complications and death rates after the PEG procedure [
28,
29,
30]. CRP level is also a risk factor for predicting overall and early mortality. Using the value of 35.9 mg/dL as a cut-off showed high sensitivity in identifying patients with worse prognosis, mainly in the very early period [
31,
32]. CRP elevation after the PEG procedure is a consequence of peritoneal reaction to pneumoperitoneum or gastric leakage. In our opinion, it can be prevented by tighter pexy of the external bumper for the first few days after PEG insertion in mobile patients. Antibiotic prophylaxis effectively reduces the risk of early complications; patients without it experience significantly more side effects. A meta-analysis of Lipp et al. [
33] showed that antibiotic prophylaxis significantly reduces the risk of infectious complications, leading to a decrease from 24.2% to 8.4%.
We observed, that patients without prophylactic PPI treatment experienced a significantly higher number of technical and late complications. We explain this observation by a lower leak of gastric juice through the stoma canal. Data assessing prophylactic PPI administration for a short-term decrease of hydrochloric acid secretion are lacking. On the other hand, several studies confirmed that long-term PPI treatment is associated with a higher complication rate when compared to non-PPI users. These complications include bowel perforation, post-PEG gastrointestinal bleeding, peritonitis, fever, pneumonia, peristomal leaks, and infection [
34,
35]. However, PPIs and histamine receptor blockers can be used to reduce gastric juice leakage when post-PEG bleeding is observed, or if ischemia and tissue ulcers occur due to internal bumps in the PEG gastrostomy tube [
8]. Proton pump inhibitors should be initiated to minimize gastric secretion in granuloma or peristomal infection [
36].
Individuals undergoing JET-PEG insertion have a higher incidence of technical complications, mainly those related to the J-tube. Compared to the N-PEG group, they underwent more re-endoscopies and analgosedations. Moreover, severe worsening of Parkinsonian motor symptoms, with the need for temporary use of rescue oral levodopa/carbidopa until the technical problem is solved, may occur due to obstruction of the J-tube. JET-PEG in individuals with PD increases their gastrointestinal morbidity, mainly with stoma pathologies. Our data show similar results as previously reported in JET-PEG individuals [
19,
20].
Subjects with PD treated by LCIG experience higher rates of gastroscopic procedures related to PEG insertion and treatment of complications related to JET-PEG such as a leak, granuloma, pain, and others. We showed that JET-PEG individuals underwent repeated endoscopies more frequently than N-PEG, and they needed PEG replacement due to technical complications more often. Based on our experience, the main reason for an increased number of re-endoscopies in the JET-PEG group was specifically related to issues linked with jejunal tube such as knotting, bezoar, removing, etc. Numerous tube and stoma complications related to LCIG jejunal therapy were reported. Similar to our experience, there was more accidental tube removal in patients with cognitive decline [
20]. Several technical problems and complications increase the annual admission rate and contact with the hospital [
37]. Inner tube complications were mostly accidental removal, kinking, or dislocation of the tube occurring during the LCIG treatment in physically active patients, sometimes suffering from disorientation [
37,
38]. Udd et al. [
20] showed that 13 out of 60 patients in their cohort had a total of 27 tube occlusions, and eight of them (61%) had altogether ten knots in the inner tube. The intestinal tube has an angled, C-shaped tip, and this may predispose the tube to knots. Removal of the inner tube occurs more often in patients with dementia as supported by previous findings [
39]. Patients with JET-PEG require a much higher degree of follow-up by gastroenterologists. Several other studies confirmed that JET-PEG individuals experience higher rates of repeated endoscopies. Sücüllü Karadağ et al. [
40] published a 36.4% incidence of technical complications, half of them requiring repeated gastroscopies [
41,
42]. Blaise et al. [
43] reported the need for repeated endoscopies in up to 68% of patients.
Limitations and Future Perspectives
Our study has several limitations inherent to the design. This is a single center, retrospective study with a relatively small sample size. Also, ECOG status was not available, due to the retrospective nature of the study. While no PD patients with N-PEG were available for analysis, a direct comparison of endoscopic complications between JET-PEG and N-PEG patients in PD specifically was not possible and this should be analyzed in future reports. In addition, future studies should focus in more details on PD characteristics (incl. motor and non-motor symptoms and fluctuations) and neurological PD periprocedural and long-term management to understand factors that might even further reduce the occurrence of endoscopic complications.