INTRODUCTION
Complications of pancreatitis are life threatening and frequently require complex treatment algorithms. Historically, surgical management carried a high morbidity with prolonged length of stay and risk of repeat procedures. Therefore, in 2013, the first prospective randomized trial was performed and reported that endoscopic and surgical cystogastrostomy had equal efficacy for drainage of pancreatic pseudocysts (PP).1 A subsequent study documented similar findings.2 While these initial reports dealt exclusively with the drainage of pancreatic pseudocysts, the endoscopic procedure has now been clinically extended, beyond its original intent, for drainage of infected peripancreatic fluid collections (IPFC, includes abscesses, infected pseudocysts, or infected liquefactive necrosis) and walled-off pancreatic necrosis (WON, sterile).3 , 4 This has marked a change in philosophy with many acute complications now being treated with internal, rather than external, drainage. While the initial results using endoscopic techniques to drain pseudocysts had been good, these expanded attempts to drain IPFCs and WON have been marred by bleeding complications, perforations, failure to adequately drain infected pseudocysts leading to sepsis, multiple reinterventions, and death.3 , 4 Despite these reports, endoscopic drainage of IPFC and WON has increased in volume and fewer surgical cyst-enteric drainage procedures are being performed, although a laparoscopic surgical approach has been shown to have a very short length of stay, a high safety profile, and a low cost.5
Referral patterns are evolving away from surgery due to high-perceived morbidity and mortality associated with early operation on necrotizing pancreatitis, before a walled-off or mature pseudocystic collection has formed. Previous reports documented that surgery on necrotizing pancreatitis within 72 hours resulted in mortality rates up to 65%.6 , 7 The surgical techniques used in these cases were distal pancreatectomies, transperitoneal approaches with debridement and packing, or transperitoneal resection with lavage.8–10 Contemporary surgeries are now carried out through videoscopic-assisted retroperitoneal debridement (VARDS), or a transgastric laparoscopic approach, with much less morbidity. Since a pseudocapsule has not yet formed early in the disease process, any attempt at a transperitoneal approach would open the lesser sac and create a vast communication between the retroperitoneum and the abdominal cavity, leading to a high rate of pancreatic fistulas and intraabdominal abscesses in these patients.11 , 12 It is now evident that patients who can avoid operative intervention for 12 or more days enjoy a greatly decreased mortality.13 , 14 This delay allows enough time for an early pseudocapsule to form within the retroperitoneum and contain the inflammatory process. If surgery can be delayed even further to 4–6 weeks, a true pseudocyst will have formed and a surgical cystogastrostomy can be created with a simultaneous debridement or necrosectomy. This procedure has a dramatically lower mortality risk than an early pancreatic necrosectomy.5
Some authors have reported that the highest success rates with endoscopic cystogastrostomy occur when there is radiographic documentation of a well-loculated, purely fluid-filled pseudocyst without any necrotic debris or infection.15 , 16 Infected pseudocysts often harbor thick pus and granular material that do not drain well via a small stent. Other reports have also documented that infected pseudocysts, or sterile pseudocysts that become infected after endoscopic stenting, often plug the stent with pus and debris, which allows the infection to persist, and can perpetuate ongoing sepsis and led to death.17 , 18 Thus, it would appear that endoscopic cystogastrostomy has proved its effectiveness for uncomplicated pseudocysts, while surgical cystogastrostomy would be more appropriate for infected pseudocysts or those with a lot of necrotic debris. Academic medical centers have standardized their approach and refer to “step up” algorithms, which match techniques to individual patient conditions.19 However, this approach is not what is always occurring in the clinical setting, and the belief that endoscopic therapy is less morbid than surgical therapy has allowed the expansive use of endoscopy for mature cystic collections of every type. Several recent reports aggregating patients from the last 10 years have documented a substantial morbidity and mortality with endoscopic cystogastrostomy for IPFCs and WON, far above what has been historically reported for surgical cystogastrostomy.15–20
Patients with pancreatitis can develop a wide-spectrum of IPFCs or WON. Each collection will vary in the amount of debris, fluid, infection, loculation, anatomical position, necrosis, and size. These patients may be hemodynamically stable or in septic shock, with varying degrees of organ failure. Research reporting on an isolated minority of homogenous fluid collections, for example, WON or PP alone, will have meaningful results that would apply to only that population, which does not reflect the variety of mature peripancreatic fluid collections that are seen in actual practice. Complicating the analysis is the fact that most published reports on endoscopic stenting of pancreatic pseudocysts include patients with infection and WON as well.17–19 , 21–26 Selection bias enters most comparisons as many endoscopic reports document results that are performed on stable patients in both the inpatient and outpatient settings, while surgical results contain both stable and septic patients who are hospitalized.22–26 This would, in theory, favor the endoscopic results. An appropriate way to determine the true morbidity, reintervention risk, and success of this heterogeneous group is to analyze all of the patient data together, using volume to create uniformity in the patient populations. Once the appropriate population is defined, one needs to compare analogous procedures, those being endoscopic cystogastrostomy with surgical cystogastrostomy, and to not include early pancreatic debridement or trans-peritoneal debridement.
There have been no recent reports in the last 5 years comparing the results of endoscopic therapy with surgical therapy for the drainage of all mature PP, IPFCs, and WON taken as a whole. It was the authors’ hypothesis that, based upon the myriad of case reports documenting complications from endoscopic therapy, surgical therapy, using either open or laparoscopic techniques, may actually have less morbidity with a higher success rate. With this in mind, the authors sought to review all of the reported series of patients undergoing endoscopic or surgical drainage of mature PP, IPFCs, or WON over the last 20 years, and determine the optimal approach based upon successful drainage, complications, reinterventions, and mortality.
METHODS
Data Collection
An online PubMed and internet review of all articles dealing with mature PP, IPFCs, or WON over the last 20 years were indexed. All English language articles in adult or pediatric populations were reviewed, and German, Russian, French, and Spanish articles if an English translation of the article could be procured. All series that had 5 patients or more who underwent endoscopic, laparoscopic, or open surgical therapy for mature PP, IPFCs, or WON were included. Authors who published many series containing the same patient population had only their largest series included to avoid duplications. Series that reported external catheter drainage were excluded. Case reports or series with less than 5 patients were excluded. Previously published meta-analysis or review articles were excluded. Series dealing with early pancreatic debridements, and not mature cystic collections, were excluded. Surgical reports of transperitoneal debridements were excluded since this is an outdated method and not technically comparable to endoscopic cystogastrostomy. All etiologies of pancreatic disease were included. Endoscopic and surgical reports that described any type of cystenterostomy creation, including cystogastrostomy, cystoduodenostomy, or cystojejunostomy, were included.
Since the majority of initial reports of endoscopic cystenterostomy began to be published 10 years ago, almost all of the endoscopic articles are from the last 10 years. To have a large enough comparison group and because laparoscopic and open surgical procedures have been performed for a longer time period, the surgical literature search was extended back 20 years.
Abstracts were examined for patient series of endoscopic or surgical drainage of mature PP, IPFCs, and WON since all of these disease processes are addressed by both open surgical, laparoscopic, and endoscopic methods in practice, and the authors were seeking “real world” results. After all of the abstracts were reviewed, those matching the topics of interest were isolated, and the full-length manuscript was obtained. Each article was read in its entirety, and the following information was extracted: number of patients, age, gender, etiology of pancreatitis, morbidity, and bleeding complications, resolution of the fluid collection, recurrence of fluid, reintervention, length of stay, follow-up, and mortality. Any kind of reintervention, endoscopic or surgical, to address a persistent fluid collection after the initial procedure, including postprocedure abscess or other complications such as bleeding, was counted as a reintervention. The only exception was endoscopic stent removal after successful drainage, which was not counted as a reintervention since this is a planned necessity poststenting. Resolution was defined as successful drainage and clinical improvement after a single intervention. The term “clinical resolution,” often used in the literature but having a variety of meanings, was not assumed to be true resolution unless there was associated radiographic documentation that the cyst had been drained to less than a 2-cm diameter (as suggested by other authors), and no further interventions were required because the patient was asymptomatic and without complications.27–29 If such documentation was not described in the manuscript or if no radiological follow-up was obtained in the study group, the resolution was labeled as “NR,” not reported. The number of patients in each study who had unsuccessful attempts at endoscopic drainage did not equal the number of reinterventions because many patients had reinterventions for complications, and many had more than 1 reintervention.
End Points
The primary endpoint of this study was to evaluate the efficacy (cyst resolution) and safety (complications, adverse events) of endoscopic cystenterostomy and surgical cystenterostomy. Secondary endpoints were reintervention rates, fluid or symptom recurrence, and mortality.
Definitions
According to the revised Atlanta criteria, PP were defined as collections of fluid that were observed after a period of more than 4 weeks, were encapsulated within a well-defined inflammatory wall, and contained no solid components or necrosis.30 Walled-off pancreatic necrosis (WON) was defined as a mature, encapsulated collection of pancreatic and peripancreatic necrosis that presented with a well-defined inflammatory wall and was present for more than 4 weeks, and clinically presumed to be sterile. Infected peripancreatic fluid collections (IPFCs) were PP or WON or other chronic, encapsulated, noncategorized fluid accumulations with documented infection. Many of the articles described “pseudocysts” with various amounts of necrotic debris, that is, 30% or 50% solid component, but since all of these collections were being included in this review, the exact naming of PP versus WON did not make any difference. Recurrence was defined as the presence of a new pseudocyst or reexpansion of the original cyst on imaging after successful treatment and shrinkage of the initial PP or WON.
Statistical Analysis
A statistical analysis was performed using a random effects model to account for between study heterogeneity. Specifically, we used a random intercept logistic regression model for each binary outcome of interest (bleeding, resolution, reintervention, recurrence, morbidly, and mortality).31 The model was fit using the LME-4 package in R, which uses maximum likelihood techniques.32 , 33 For each outcome, we obtained estimates, standard errors, and 95% confidence intervals (CI) for the mean proportion of individuals with that outcome after receiving surgery or endoscopy. We also obtained estimates, standard errors, 95% CI, and P values (testing for a difference from 0) for the log odds ratio between surgery and endoscopy for that outcome. For each continuous outcome of interest (ie, length of stay and follow-up), we estimated the overall mean using a random intercept model with inverse variance weighting for pooling each study’s mean.34 As we were unable to obtain standard deviations for all the individual studies, we used conservative estimates of the studies’ standard deviations in our analysis. The model was fit using the meta package in R.33 , 35 For each outcome, we obtained estimates, standard errors, and 95% confidence intervals for the mean after receiving surgery and endoscopy. We also obtained estimates, standard errors, 95% confidence intervals, and P values (testing for a difference from 0) for the difference in means between surgery and endoscopy for that outcome.
To evaluate if the endoscopic and surgery patient populations were similar, we compared the age, gender, and etiology of pancreatitis between the groups. Additional comorbidity data were very limited or absent in most of the endoscopic manuscripts, which limited further comparison of other patient characteristics. Institutional review board approval for this study was obtained from the St Joseph Mercy Health System.
RESULTS
We identified 1346 articles that covered the topics of interest, and from those, there were 27 surgical articles20 , 36–61 and 58 endoscopic articles15–18 , 20–29 , 59 , 62–104 that met criteria. From these 85 articles, we reviewed the results for 5588 patients. See Tables 1 and 2 and PRISMA flow diagram.
TABLE 1. -
Results of Surgical Cystenterostomy
Author
n
Bleeding
Resolution*
Reintervention
Recurrence
LOS
Follow-up
Morbidity
Mortality
Boutros
19
0
19 (100%)
0
0
7 d
31 mos
NR
0
Palanivelu
100
2 (2%)
100 (100%)
2 (2%)
1 (1%)
6 d
54 mos
NR
0
Yin
12
1 (8%)
12 (100%)
1 (8%)
1 (8%)
NR
108 mos
3 (25%)
0
Hauters
12
0
12 (100%)
0
1 (8%)
6 d
12 mos
1 (8%)
0
Parks
28
0
28 (100%)
0
0
7 d
NR
10 (36%)
0
Hindmarsh
15
0
15 (100%)
0
2 (13%)
NR
37 mos
2 (13%)
0
Bansal
134
3 (2%)
128 (96%)
0
0
4 d
66 mos
14 (10%)
0
Khaled
54
0
53 (98%)
0
1 (2%)
8 d
18 mos
12 (23%)
1 (2%)
Gibson
44
1 (2%)
44 (100%)
1 (2%)
1 (2%)
6 d
74 mos
1 (2%)
0
Hamza
29
0
29 (100%)
0
2 (7%)
3 d
15 mos
1 (3%)
0
Melman
38
1 (3%)
35 (92%)
1 (3%)
1 (3%)
9 d
10 mos
10 (25%)
0
Barragan
8
0
8 (100%)
0
0
6 d
NR
0
0
Obermeyer
6
0
6 (100%)
0
0
5 d
44 mos
1 (17%)
0
Mori
14
0
14 (100%)
1 (7%)
1 (7%)
NR
NR
NR
0
Saluja
20
0
20 (100%)
0
0
5 d
24 mos
2 (10%)
0
Robin
119
2 (1.7%)
111 (93%)
4 (3.4%)
9 (7.6%)
10 d
12 mos
36 (30%)
2 (1.7%)
Martinez
111
6 (5%)
111 (100%)
0
7 (6%)
NR
NR
25 (23%)
2 (1%)
Marino
48
0
44 (92%)
5 (10%)
0
10 d
NR
5 (10%)
0
Gerin
11
1 (9%)
11 (100%)
0
1 (9%)
16 d
10 mos
2 (18%)
0
Crisanto
20
0
19 (94%)
0
0
7 d
40 mos
1 (6%)
0
Simo
22
0
22 (100%)
0
0
14 d
2 mos
1 (4.5%)
0
Ramachandran
5
0
5 (100%)
0
0
4 d
12 mos
0
0
Oida
7
0
7 (100%)
0
0
8 d
65 mos
0
0
Kulkarni
22
0
20 (90%)
1 (4.5%)
1 (4.5%)
7 d
12 mos
7 (32%)
0
Malik
12
0
12 (100%)
0
0
4 d
NR
2 (17%)
0
Yoder
13
1 (8%)
12 (92%)
1 (8%)
0
4.5 d
NR
1 (8%)
0
Driedger
178
6 (3%)
NR
23 (13%)
12 (7%)
8 d
21 mos
68 (38%)
4 (2%)
Total
1101
*Resolution was defined as success after a single procedure.
NR indicates not reported.
TABLE 2. -
Results of Endoscopic Cystenterostomy
Author
n
Bleeding
Resolution*
Reintervention
Recurrence
LOS
Follow-up
Morbidity
Mortality
Teoh
59
3 (5%)
NR
20 (34%)
2 (3.4%)
11 d
11 mos
5 (8.4%)
2 (3%)
Shekhar
100
4 (4%)
89 (89%)
11 (11%)
1 (1%)
NR
12 mos
9 (9%)
0
Melman
45
2 (4%)
23 (51%)
16 (36%)
NR
NR
NR
7 (16%)
0
Rasmussen
22
NR
13 (59%)
9 (41%)
4 (18%)
NR
NR
NR
0
Yamamoto
9
1 (11%)
7 (78%)
2 (22%)
NR
NR
NR
2 (22%)
0
Attam
10
1 (10%)
9 (90%)
10 (100%)
2 (20%)
NR
NR
3 (30%)
1 (10%)
Nelsen
5
0
2 (40%)
0
3 (60%)
NR
10 mos
0
0
Sharaiha
124
2 (1.6%)
NR
30 (24%)
6 (5%)
NR
3 mos
23 (19%)
0
Will
27
1 (4%)
NR
27 (100%)
NR
NR
NR
3 (11%)
1 (3.7%)
Ahlawat
12
0
NR
3 (25%)
2 (17%)
NR
4 mos
3 (25%)
0
Xu
108
6 (5.5%)
NR
8 (7%)
9 (8.3%)
NR
6 mos
8 (7%)
4 (3.7%)
Gambitta
91
1 (1%)
73 (80%)
24 (26%)
17 (19%)
NR
NR
5 (5%)
2 (2%)
Laique
88
2 (2%)
70 (80%)
10 (11%)
6 (7%)
6 d
14 mos
19 (22%)
2 (2%)
Garg
30
3 (10%)
23 (77%)
27 (90%)
5 (17%)
NR
22 mos
7 (23%)
0
Shin
27
2 (7%)
NR
NR
9 (30%)
NR
8 mos
6 (22%)
0
Saluja
35
0
27 (78%)
6 (17%)
NR
6 d
24 mos
10 (29%)
0
Yamauchi
36
NR
NR
NR
NR
NR
56 mos
20 (56%)
2 (6%)
Yao
125
5 (4%)
113(90%)
17 (14%)
3 (2.4%)
NR
26 mos
24 (19%)
2 (1.6%)
Yang
205
NR
186 (91%)
19 (9%)
29 (14%)
5 d
6 mos
28 (13%)
0
Puga
41
6 (15%)
NR
NR
NR
NR
29 mos
11 (27%)
0
Venkata
116
1 (0.8%)
110 (95%)
8 (7%)
1 (0.8%)
3 d
6 mos
13 (11%)
4 (3.4%)
Brimhall
249
20 (8%)
134 (54%)
11 (4.4%)
13 (5.2%)
NR
NR
51 (20%)
2 (0.8%)
Ge
52
2 (4%)
NR
8 (15%)
NR
8 d
NR
4 (8%)
0
Keane
109
2 (2%)
76 (70%)
31 (28%)
8 (7%)
4 d
11 mos
13 (12%)
0
Siddiqui
80
6 (7.5%)
72 (90%)
60 (75%)
1 (1%)
NR
8 mos
13 (16%)
NR
Yuan
47
NR
NR
NR
3 (6%)
11 d
48 mos
18 (38%)
0
Bapaye
21
1 (5%)
21 (100%)
1 (5%)
0
NR
1.5 mos
2 (10%)
0
Walter
61
4 (7%)
51 (83%)
23 (38%)
NR
NR
NR
21 (34%)
0
Chandran
47
3 (5.5%)
36 (77%)
10 (21%)
4 (8.5%)
NR
8 mos
26 (55%)
4 (8.5%)
Lin
90
4 (4%)
85 (94%)
7 (8%)
5 (5.5%)
10 d
48 mos
13 (14%)
0
Ng
61
1 (2%)
46 (75%)
13 (21%)
6 (10%)
NR
11 mos
16 (26%)
0
Due
10
NR
6 (60%)
4 (40%)
4 (40%)
NR
4 mos
4 (40%)
1 (10%)
Bang
122
3 (2%)
102 (84%)
21 (17%)
NR
NR
NR
7 (6%)
1 (1%)
Mukai
89
2 (2%)
70 (79%)
37 (42%)
NR
NR
24 mos
11 (12%)
3 (3%)
Smoczynski
97
19 (20%)
78 (80%)
35 (36%)
19 (20%)
29 d
31 mos
29 (30%)
2 (2%)
Kato
67
NR
NR
11 (16%)
16 (24%)
NR
34 mos
1 (1.5%)
0
Binmoeller
14
1 (7%)
11 (79%)
5 (36%)
NR
NR
3 mos
3 (21%)
0
Rische
40
NR
NR
106 (265%)†
4 (10%)
30 d
31 mos
14 (35%)
3 (7.5%)
Weilert
18
0
14 (78%)
8 (44%)
NR
NR
NR
6 (33%)
3 (17%)
Fabbri
20
NR
17 (85%)
2 (10%)
1 (5%)
NR
20 mos
3 (15%)
0
Puri
40
1 (2.5%)
39 (98%)
1 (2.5%)
1 (2.5%)
NR
48 mos
3 (8%)
0
Seewald
80
12 (15%)
58 (73%)
22 (28%)
9 (11%)
NR
31 mos
21 (26%)
0
Varadarajulu
211
3 (1%)
180 (85%)
34 (16%)
NR
3 d
12 mos
17 (8%)
5 (2%)
Ahn
47
1 (2%)
42 (89%)
7 (15%)
5/41 (12%)
NR
17 mos
5 (11%)
0
Gornals
19
0
NR
13 (68%)
3 (16%)
NR
12 mos
5 26%)
0
Cavallini
55
2 (4%)
43 (78%)
12 (22%)
8 (14%)
NR
34 mos
9 (16%)
1 (1.8%)
Sharma
144
8 (5.5%)
140 (97%)
24 (17%)
13 (9%)
NR
18 mos
26 (18%)
1 (0.7%)
Petrone
67
5 (7%)
NR
14 (21%)
2 (3%)
NR
NR
16 (24%)
NR
Aburajab
47
0
44 (94%)
4 (8.5%)
4 (9%)
NR
NR
12 (26%)
0
Ruckert
51
2 (4%)
22 (43%)
25 (49%)
7/30 (23%)
NR
42 mos
16 (31%)
3 (6%)
Wantanabe
103
2 (2%)
80 (78%)
37 (36%)
10/75(13%)
NR
38 mos
15 (15%)
3 (3%)
Nabi
30
4 (13%)
28 (93%)
7 (23%)
2 (7%)
NR
28 mos
10 (33%)
0
Ang
49
1 (2%)
36 (73%)
21 (43%)
NR
NR
NR
5 (10%)
0
Vazquez
211
15 (7%)
178 (84%)
33 (16%)
NR
NR
NR
44 (21%)
NR
Thompson
60
8 (13%)
52 (86%)
21 (35%)
8 (13%)
NR
17 mos
NR
0
Dhir
47
NR
42 (89%)
12 (26%)
2 (4%)
NR
10 mos
4 (9%)
0
Fugazza
311
22 (7%)
272 (87%)
56 (18%)
27 (9%)
NR
5 mos
74 (24%)
2 (0.6%)
Parsa
306
12 (4%)
281 (92%)
45 (15%)
NR
13 d
6 mos
53 (17%)
0
Total
4487
*Resolution was defined as success after a single procedure
† Every patient had at least 2 repeat interventions.
NR indicates not reported
The patients within the endoscopy and surgery groups were comparable, with similar age (surgery mean 48 years, CI, 44–52, endoscopy mean 51 years, CI, 49–53), gender (surgery males 69%, CI, 62–75%, endoscopy males 68%, CI, 65–71%), and percentage of the group having alcohol as the etiology of their pancreatitis (surgery 29%, CI, 23–35%, endoscopy 37%, CI, 32–42%). See Table 3 for results from significance tests comparing these patient populations, and see Tables 4 and 5 for raw data.
TABLE 3. -
Demographics Comparison
Surgery
Endoscopy
P
Mean age
48, CI, 44–52
51, CI, 49–53
0.12
Male gender
69%, CI, 62–75
68%, CI, 65–71
0.87
Alcohol etiology
29%, CI, 23–35
37%, CI, 32–42
0.06
TABLE 4. -
Demographics of Surgical Cystenterostomy
n
Mean Age
Gender % Male
Alcohol Etiology(%)
Boutros
19
56
63
42
Palanivelu
100
44
70
19
Yin
12
38
64
46
Hauters
12
46
42
Parks
28
50
55
33
Hindmarsh
15
59
33
20
Bansal
134
36
86
25
Khaled
54
53
70
40
Gibson
44
54
66
32
Hamza
29
53
64
39
Melman
38
49
55
Barragan
8
Obermeyer
6
39
67
33
Mori
14
55
79
29
Saluja
20
37
Robin
119
52
90
45
Martinez
111
74
Marino
48
48
Gerin
11
61
67
23
Crisanto
20
40
54
18
Simo
22
51
65
29
Ramachandran
5
56
55
14
Oida
7
61
60
0
Kulkarni
22
51
100
71
Malik
12
52
59
14
Yoder
13
10
75
0
Driedger
178
51
64
31
Total
1101
TABLE 5. -
Demographics of Endoscopic Cystenterostomy
Author
n
Mean age
Gender % Male
Alcohol Etiology (%)
Teoh
59
45
81
34
Shekhar
100
56
59
38
Melman
45
52
71
Rasmussen
22
51
59
41
Yamamoto
9
Attam
10
53
80
10
Nelsen
5
57
100
Sharaiha
124
Will
27
Ahlawat
12
Xu
108
52
56
18
Gambitta
91
Laique
88
53
60
48
Garg
30
38
73
27
Shin
27
56
81
Saluja
35
37
80
34
Yamauchi
36
54
83
47
Yao
125
48
66
Yang
205
55
63
32
Puga
41
Venkata
116
53
67
36
Brimhall
249
48
65
31
Ge
52
50
56
Keane
109
55
55
19
Siddiqui
80
Yuan
47
48
62
43
Bapaye
21
47
86
63
Walter
61
Chandran
47
51
68
38
Lin
90
49
67
16
Ng
61
49
70
66
Due
10
53
80
Bang
122
49
52
38
Mukai
89
56
81
56
Smoczynski
97
Kato
67
56
75
Binmoeller
14
50
64
50
Rische
40
56
75
Weilert
18
50
67
44
Fabbri
20
57
85
35
Puri
40
39
78
60
Seewald
80
56
61
10
Varadarajulu
211
48
58
33
Ahn
47
46
85
68
Gornals
19
57
68
32
Cavallini
55
54
55
4
Sharma
144
36
82
47
Petrone
67
59
69
12
Aburajab
47
Ruckert
51
Wantanabe
103
55
71
50
Nabi
30
73
Ang
49
53
51
Vazquez
211
Thompson
60
54
60
28
Dhir
47
Fugazza
311
Parsa
306
55
70
Total
4487
For the outcome of postprocedure bleeding complications, the percentage of surgical patients with a bleeding complication was 1.8% (CI, 0.0097–0.0342) and for endoscopy was 4.3% (CI, 0.0337–0.0558). There was a significantly decreased risk of postoperative bleeding after surgery, with a log odds ratio of –0.906 (SE 0.362, P = 0.012; see Figs. 1 and 2 ).
FIGURE 1.: Estimated odds ratio of each parameter listed for surgery compared to endoscopy.
FIGURE 2.: Estimated proportion of each parameter listed for surgery compared to endoscopy.
When comparing the chance of complete pseudocyst resolution after having surgery as compared to endoscopic intervention, surgical patients had complete resolution of their cyst 98.5% (CI, 0.959–0.995) of the time, compared to 83.5% (CI, 0.796–0.868) after endoscopic interventions. There was a much higher chance of having complete pseudocyst resolution after surgery, with a log odds ratio of 2.64 (SE 0.582, P < 0.0001).
In terms of repeat interventions postprocedure, including repeat interventions to drain persistent fluid collections, repeat interventions for bleeding, occluded stents, abscesses, or other complications, the risk of repeat interventions after surgical drainage was 3.9% (CI, 0.0266–0.0572) and after endoscopic procedures was 25.8% (CI, 0.1934–0.3354). This does not include repeat endoscopic intervention for planned stent removal after pseudocyst resolution, which is an expected event. Thus, surgical patients were at a greatly reduced chance of requiring any type of reintervention with a log odds ratio of –3.33 (SE 0.508; P < 0.0001).
The risk of pseudocyst recurrence, when given as a statistic, must be indexed for the length of time that a patient is followed, as the risk increases over time. Without this adjustment, the results would be skewed in favor of the group with shorter follow-up because pancreatitis tends to be a chronic and recurrent disease. Therefore, the results of pseudocyst recurrence are examined in conjunction with length of follow-up. The surgical patients had much longer follow-up, with a mean of 34.0 months (CI, 20.5–47.3). Mean endoscopic follow up was 19.4 months (CI, 15.0–23.8). The difference was small, but statistically significant (P = 0.04). However, despite the longer follow-up in the surgical group, the recurrence risk was much less at 2.3% (CI, 0.0124–0.0439) compared with the recurrence risk with endoscopic intervention, which was 8.8% (CI, 0.0679–0.1130). Thus, even taking into account the differences in follow-up, the risk of pseudocyst recurrence is much less with surgical cystogastrostomy, with a log odds ratio of –1.405 (SE 0.366, P < 0.001).
Although surgical cystogastrostomy is often cited as “more risky” than endoscopic therapy, the overall morbidity with surgery was actually less than with endoscopic stenting (13.5%, CI, 0.0934–0.1913 versus 17.8%, CI, 0.1509–0.2089). The log odds ratio slightly favored surgery at –0.326, although not statistically significant (SE 0.232, P = 0.16). Both procedures had a very low mortality, with surgery slightly less at 0.5% (CI, 0.00121–0.0201) compared with endoscopic interventions at 0.9% (CI, 0.0051–0.0157). Again the log odds ratio slightly favored surgery at –0.673 but was not significant (SE 0.943, P = 0.48).
There was no significant differences in postprocedure length of hospital stay, with a mean length of stay after surgery of 7.1 days (CI, 5.9–8.4) and a mean length of stay after endoscopic interventions of 9.4 days (CI, 4.2–14.5, P value for the difference = 0.61).
DISCUSSION
Despite the common assumption, the endoscopic therapy is safer and less morbid than surgical intervention on the pancreas; the results of this study overwhelmingly favor surgery for several important endpoints. The data could be used to challenge the assumption that surgery can always be performed if endoscopic therapy fails, as this logic is clearly flawed. Failed endoscopic therapy increases the chances of bleeding, prolongs the duration of sepsis for IPFCs, and has a greater morbidity than surgical intervention alone. Other authors have also shown that a patient’s risk of complications goes up when surgery is performed after failed endoscopic therapy, as opposed to those who went directly to surgery.36
From a pathophysiological perspective, a large surgical cystogastrostomy will allow ongoing pancreatic fluid from ductal disruption to drain into the stomach until the pancreas heals. In those patients who develop a pancreatic pseudocyst due to a significant disruption in the duct of Santorini or the duct of Wirsung, an ongoing pancreatic leak and fistula can be expected, and are slow to heal even if the duct is stented by ERCP.93 For these patients who have had a surgical cystogastrostomy or cystoduodenostomy, the ongoing fistula will continue to drain into the foregut and the output will be controlled internally. However, if these patients were treated by an endoscopic stent, the stent will need to remain in place indefinitely until the leak resolves, which can take up to 13 months or longer93 , 105 Some authors even recommend leaving the stents in place indefinitely.106 This is problematic since the longer a stent stays in place, the higher the complication rate from erosion into the surrounding vessels or viscera.65 , 67 , 71 , 75 , 84 , 88
Historically, all pseudocyst walls are biopsied at the time of cystogastrostomy creation to ensure that the pseudocyst is not really a cystadenocarcinoma of the pancreas. In all of the endoscopic series reviewed in this article, very few of the endoscopic reports described performing a biopsy at the time of cystogastrostomy creation. Other authors have recommended sampling and testing the cyst fluid for carcinoembryonic antigen or CA 19-9 to ensure no malignancy is present.94 While the risk of missing a cancer is considered low, it is not zero, and cases of pancreatic cancer are still being reported from presumed pseudocysts.95 , 107 , 108 A recent report found a 1.8% incidence of pancreatic cancer by brush cytology of WOPN, while another found a frequency of 1.25% in peripancreatic fluid collections.96 , 109
Many endoscopic cystogastrostomy studies document “clinical success,” which they define as symptomatic improvement only, although some authors consider “success” to be any decrease in the size of the pseudocyst by more than 1 cm.75 Other authors have defined “clinical success” to be resolution of symptoms and a decrease in the size of the pseudocyst by >40%.80 While other authors define success as the pseudocyst shrinking to less than 3 cm.67 Others think that clinical success is a size reduction of >50% or to a size <5 cm.83 , 110 While still other authors feel that clinical success is defined by “a distinct decrease in the size of the cyst after a drainage period of six months.”97 This variable and misleading idea of success leads to the propagation of the belief that endoscopic techniques are more successful than they actually are. We only found 5 endoscopic reports that documented follow-up CT scans or ultrasound imaging in all of their patients.22 , 24 , 91 , 97 , 98 Not surprisingly, all of these studies reported very high rates of reintervention for the persistent pseudocysts. Not only is the idea of “clinical success” misleading, but it also can be dangerous since we know from the natural history of pseudocysts that their persistence often leads to vascular erosion and hemorrhage, as one of the authors has previously reported.111 The presence of metal stents within the pseudocyst also appears to significantly increase the risk of hemorrhage.24 , 99 , 100 , 109
Multiple studies from the literature show that endoscopic stenting nearly always fails when there is greater than 50% parenchymal necrosis.101 , 112 , 113 Three multicenter trials in patients with primary pancreatic necrosis found that attempts at endoscopic necrosectomy had very high morbidity (26%–33%) and mortality rates (6%–11%).112–114 Another recent multicenter study involving 333 endoscopic procedures for peripancreatic fluid collections, many with a large necrotic component, found an adverse event rate of 24%.102 Thus, while endoscopic cystogastrostomy with stenting is useful for PP that are purely cystic with minimal necrotic debris, any IPFC or WON with a large solid or granular component or >50% parenchymal necrosis will be better served going directly to surgery. Surgery as primary therapy has less morbidity, mortality, recurrence, reintervention, and greater resolution than endoscopic treatments.
This study is limited by the fact that most of the reviewed articles included in the analysis were retrospective studies, and only a few were prospective trials. Thus, the analysis carries over the retrospective biases present in the original articles, including potential confounding variables and selection bias due to nonrandomization. All of the results can be interpreted as associational. However, the causal interpretation should be further assessed. Also, grouping together the disease processes into 1 large group may lead to potential bias. For example, if a majority of papers focus on a specific type of peripancreatic fluid collection, then the results will also be weighted toward results from that process. We did find, fortunately, that the results are not strongly influenced by any single paper within the study.
This article has ramifications for policy makers, administrators, and those institutions that have begun to follow a step-up approach to IPFCs, since endoscopic therapy is not a benign procedure and carries greater morbidity and mortality risk than surgery for the creation of a cystogastrostomy.
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