This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Sedlack, R. E. Articles by Baron, T. H. Search for Related Content PubMed PubMed Citation Articles by Sedlack, R. E. Articles by Baron, T. H. Social Bookmarking                   What's this?

Percutaneous Endoscopic Gastrostomy Placement Without Skin Incision: Results of a Randomized Trial

From the Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota

Correspondence: Todd Baron, MD, 200 1^st Street SW, Rochester, MN 55905. Electronic mail may be sent to baron.todd{at}mayo.edu.

Background: During percutaneous endoscopic gastrostomy (PEG) placement, skin incision is performed as standard practice. We suspected that this time-honored principle is unnecessary. Methods: In a prospective, randomized trial, 50 adults undergoing PEG placement were randomized to skin incision omission PEG (IOPEG) and standard PEG (SPEG). Two- and 7-day PEG site evaluations were performed to grade stomal infection, bleeding, pain, and overall satisfaction using a standardized scoring system. Median stomal evaluation scores were compared between groups using a Wilcoxon rank-sum test. Completion rates were compared using a t-test. Results: Placement success for the IOPEG and SPEG technique was 22/25 (88%) and 24/25 (96%), respectively (p = NS). Three failed IOPEG attempts required an incision to complete due to increased pull force encountered. One SPEG failed due to inability to transilluminate. Stomal evaluation scores of infection, bleeding, pain, leakage, and patient satisfaction were not significantly different at 2 or 7 days. No serious complications occurred as a result of skin incision omission. Conclusions: Omitting the skin incision does not significantly alter the placement success rate, patient satisfaction, or the rate of stomal complications, thus dispelling the dogma that a skin incision is mandatory for PEG placement and the myth that incisions reduce infectious complications.

Percutaneous endoscopic gastrostomy (PEG) tube placement was first described in the early 1980s and has largely replaced surgical gastrostomy because of reductions in cost, morbidity, and mortality.^1–4 PEG placement, however, is still associated with morbidity rates ranging from 3% to 32%.^5–7 Complications include wound infection, fever, pain, and hematoma. These local complications usually occur within the first week, and nearly 50% occur within the first 48 hours.⁸ According to Medicare data alone, over 100,000 PEG tubes are placed by gastroenterologists annually in the United States.⁹ Thus, the potential worldwide morbidity and cost of PEG stomal complications is substantial.

The technique for endoscopic placement developed by Drs Gauderer and Ponsky involves the use of a dilating skin incision using a scalpel.^2,3 This technique has become the standard method of PEG tube placement.¹⁰ Feeding tubes used in the development of their procedure were 16-Fr de Pezzer (mushroom) surgical catheters and did not possess tapered, self-dilating tips. Thus, the dilating skin incision was necessary for placement. Later versions included the addition of an inverted angiocatheter at the tip to act as a dilator.² Durable, dilating tips are now standard on all commercially available PEG kits, possibly obviating the need for skin incisions. Despite advances in PEG tube design, the skin incision portion of PEG placement has remained. In fact, it has been suggested that larger skin incisions reduce infectious complications by allowing egress of bacteria and gastric secretions.^11,12

The potential advantages of omitting the skin incision during PEG placement are the preservation of an intact skin barrier to reduce the chance for bacterial invasion and infection, as well as the avoidance of scalpel injuries to health care personnel, the decrease in cost of the kits, and the reduction in disposable biohazardous medical waste. Before embarking on a randomized prospective trial of skin incision omission PEG (IOPEG) vs standard PEG (SPEG) placement with skin incision, we performed and published a prospective pilot study in 20 patients that demonstrated the safety and feasibility of omitting the skin incision from the traditional endoscopic pull-through technique.¹³ We found that the dilating skin incision was not necessary and may contribute to stomal infections. We thus performed a randomized controlled trial to directly compare this IOPEG technique to the SPEG method.

	METHODS

Top METHODS RESULTS DISCUSSION

 
Subjects
This study was approved by the Mayo institutional review board (IRB). Fifty consecutive patients referred for PEG feeding tube placement that met inclusion criteria and consented were enrolled. Inclusion criteria included adult patients (age 18 years of age) who were willing and able to follow the study protocol and participate in 2-day and 7-day examination. Patients were excluded from participating if they were pregnant, had preexisting cellulitis or erythema of the abdominal wall, were undergoing simultaneous direct percutaneous jejunostomy, receiving anticoagulation, international normalized ratio (INR) >1.7, platelet count <40,000, or were receiving corticosteroids on a chronic basis. Informed consent was obtained from each patient or legal guardian.

Fifty patients were enrolled (25 per group). IOPEG and SPEG subject ages averaged 62 (range, 21–87) and 71 (40–92) years old, respectively. Male:female ratios were roughly equivalent for IOPEG (15:10) and SPEG (17:8) groups. Average BMI (kg/m²) was also similar, at 24.1 (range, 17–37.8) and 24.9 (16.8–35.5) for the IOPEG:SPEG respectively. The clinical indications for feeding-tube placement were also roughly the same for IOPEG:SPEG, with neurologic causes (CVA, CNS tumor, ALS, or MS) topping the list for each group (48%:36% respectively). Other indications (with respective proportions) included head/neck cancer (36%: 24%), esophageal cancer (4%:16%), and all other indications combined (12%:20%).

Randomization
After screening, consent, and entry questionnaire, patients were randomized (1:1) to IOPEG or SPEG. Randomization was accomplished using 50 sealed envelopes with 1:1 ratio of IOPEG:SPEG. Once eligibility was confirmed and the patient consented, the envelope was opened, assigning the patient to a study arm. The patient was blinded to arm assignment.

Treatment
SPEG. This procedure is outlined in previous publications and in summary involves the conscious sedation of the patient with variable doses of IV midazolam (1 mg/mL) and narcotic analgesia (fentanyl or meperidine), with subsequent insertion of a video endoscope (Olympus Corporation, Melville, NY). An appropriate PEG placement site was determined by transillumination and indentation. Once the optimal site was identified, the area was prepped and draped sterilely. Xylocaine was used for local anesthesia. The remainder of the procedure proceeded as per standard pull technique, including the performance of a 1-cm dilating skin incision using a disposable scalpel. A SPEG tube kit was used for all cases (20 Fr; MIC tube kit; Kimberly-Clark [Formerly by Ballard Medical], Draper, UT; Figure 1). To measure the force required to pull each tube through the abdominal wall, a BG50 digital force gauge (MARK-10, Hicksville, NY) was attached to the extraabdominal end of the insertion wire and zeroed, just before pulling the dilating tip of the feeding tube through the wall of the abdomen. The strain gauge was used to pull the wire and attached dilating tip of the PEG feeding tube out though the abdominal wall along the wire track. Peak traction forces (lbs) were measured during the pull-through. Smooth, gradually increasing traction was used to avoid recording falsely elevated impulse forces.

View larger version (25K): [in this window] [in a new window]   FIGURE 1. Shown are the dimensions of the dilating tip from a 20-Fr MIC tube (Kimberly-Clark).

Follow-up
At 2 days and 7 days from the time of the tube placement, the ostomy site was examined and a questionnaire administered. This examination was performed by one of the investigators or LPN study coordinator using a standardized grading form (Figure 2).

View larger version (18K): [in this window] [in a new window]   FIGURE 2. Patient follow-up survey.

Peak traction pull force required to pull the self-dilating PEG tip through the abdominal wall was recorded in pounds.

Two- and 7-day evaluations were performed by either a gastroenterology fellow involved as a study investigator or the nurse study coordinator, at which time stomal evaluations were recorded. The type of technique used during feeding tube placement was readily obvious; hence, blinding of the stomal evaluator was not undertaken. Infection and bleeding scores were based on criteria in Figure 2. Total infection scores were made up of a combined score of the following individual scores:

1. Peristomal erythema (diameter in mm; none = 0, 5 mm = 1, 6–10 mm = 2, 11–15mm = 3, 16–20 mm = 4, >20 mm = 5)
   
2. Swelling (none = 0, minimal = 1, moderate = 2, severe = 3)
   
3. Exudate (none = 0, serous = 1, serosanguineous = 2, sanguinous = 3, purulent = 4)
   

A total infection score of >5 was deemed to indicate a clinically significant infectious complication. The concomitant administration of antibiotics beyond simple prophylaxis was recorded. Wound cultures were not obtained unless there was clinical evidence of infection.

A total bleeding score was calculated as the sum of the following individual scores:

1. Peristomal hematoma (diameter in mm; none = 0, 5 mm = 1, 6–10 mm = 2, 11–15 mm = 3, 16–20 mm = 4, >20 mm = 5)
   
2. Ecchymosis (diameter in mm; none = 0, 5mm = 1, 6–10 mm = 2, 11–15 mm = 3, 16–20 mm = 4, >20 mm = 5)
   
3. Stomal oozing: (none = 0, minimal = 1, moderate = 2, severe = 3)
   

A total bleeding score of >5 was deemed to indicate a clinically significant bleeding complication. INR values are performed as part of all PEG placements at Mayo and were recorded. The concomitant use of aspirin or other anticoagulation therapy was also recorded.

Peristomal pain was evaluated at 2 and 7 days using a Likert scale of 0–10 (0 = none, 10 = severe). Overall PEG satisfaction was similarly evaluated using a Likert scale of 1–5 (1 = completely satisfied, 3 = neutral, 5 = completely dissatisfied).

Study Aims
Primary Aim. Comparison of stomal infection scores at 2 days and 7 days after IOPEG or SPEG placement.

Secondary Aims. To compare rates of successful IOPEG and SPEG Placement.

To compare maximum traction force required to pull the PEG tubes through the abdominal wall using a digital force gauge.

To compare ostomy bleeding scores at 2 and 7 days. To compare peristomal leakage scores at 2 and 7 days.

To compare overall patient satisfaction and PEG site pain.

Sample Size Calculations
Infection. Using the infection scoring system outlined above, mean infection scores for SPEG placement at our institution in patients receiving prophylactic antibiotic therapy have been recorded in historical data (1980) at 2.04.¹⁴ Experience from our pilot study suggests median infection scores associated with the IOPEG method of 0.2 at 2 days and 0.8 at 7 days, with a standard deviation of 0.46.¹³ For this study, we used the same infection scoring system as these previous 2 studies. Assuming the IOPEG had a mean infection score as high as 1.0 and SPEG a mean as low as 1.75, 12 patients in each group will have >80% power to detect the difference between a null hypothesis mean of 1.75 and an alternative mean of 1.0, using a 2-sample t-test with a 0.050 2-sided significance level and assuming that the standard deviation is 0.60.

Placement Completion Rates. We anticipated that successful placement rates would be the same between the 2 procedures, at approximately 95%. SPEG completion rates are published at roughly 95%. Our IOPEG pilot study demonstrated 100% placement success in 20 patients. IOPEG success would have needed to drop from 95% to 70% (8 failures out of 25 patients) to demonstrate a statistical difference using a Fisher's exact test and 25 patients per arm.

Traction Pull Forces. Published mean pull forces for SPEG placement are 9.8 lbs. IOPEG placement mean force is approximately 14 lbs. We assumed SPEG mean pull forces to be 9.0, with a standard deviation of 6.0; we would have >80% power to detect a difference in pull forces if IOPEG mean were 15 pounds using a 2-group t-test with 0.05 2-sided significance when 20 subjects are in each group.

Stomal Bleeding, Pain, Leakage, and Patient Satisfaction. There are no published SPEG data using a similar scoring system with which to compare our IOPEG pilot data for meaningful power calculations.

Data Analysis
Placement completion results were compared doing equality testing using a 2-tailed Fisher's exact test, with the null hypothesis being that there is a difference in the respective completion rates and the alternate hypothesis being that there is no significant difference in completion proportions. Median traction pull forces were compared between the 2 arms using Wilcoxon rank-sum test. Median 2- and 7-day wound evaluation scores (composite infection, bleeding, and pain scores) and median patient satisfaction scores for each arm were also compared for each parameter by Wilcoxon rank-sum test. A 2-tailed Fisher's exact test was used to compare the use of antibiotics, and pain medications between the 2 arms during 2- and 7-day evaluations. All statistics were performed using JMP statistics software (version 5.1.2; SAS Institute Inc, Cary, NC).

	RESULTS

Top METHODS RESULTS DISCUSSION

 
Two-day stomal evaluations were completed in 82% of subjects and in 50% of the patients at 7 days (Table I). In the IOPEG group, 3 were eliminated from participation in stomal evaluation due to initial tube placement failure by intent to treat. Three were lost to follow-up, leaving 19 subjects for the 2-day evaluations. Of these 19, 1 was unable to answer satisfaction and pain questions due to neurologic changes associated with a CVA. An additional 7 subjects were lost to follow-up at the 7-day evaluation in this group. For the SPEG group, 1 patient was lost by intent to treat during placement, and 2 more were simply lost to follow-up for stomal examinations, leaving 22 subjects in the 2-day stomal evaluation scores. Of these, 2 were unable to answer the patient pain and satisfaction survey due to CVA neurologic deficits. At 7 days, 9 additional patients were lost to follow-up, including these 2 CVA patients, leaving 13 patients for stomal, pain, and satisfaction evaluations. As in the IOPEG group, this 7-day dropout resulted from the fact that many patients were discharged in the week after PEG placement and were not available for 7-day evaluations. All attempts were made to contact the patients or nursing home staff to allow for stomal follow-ups, yet an unexpectedly high number of patients had left the local area, making stomal evaluations by our research team impossible.

No statistical significance was seen in median stomal infection, ostomy bleeding scores, peristomal leakage scores, or overall patient satisfaction and PEG-site pain scores at 2 days and 7 days after IOPEG or SPEG placement (Table I). No serious complications occurred as a result of skin incision omission. Notably, fewer IOPEG patients were receiving pain medications for any reason at 7 days, though this was not significantly different. Also notable is that a significantly greater number of patients in the IOPEG group continued to receive antibiotics for non-PEG indications compared with the SPEG group (Table I).

Successful placement was achieved in the IOPEG group in 22/25 (88%) and in the SPEG group 24/25 (96%; p = .609; Table II). The 3 failed IOPEG patients required an incision due to the perception of increased pull force encountered. One SPEG failed due to inability to transilluminate. With the elimination of the SPEG transillumination failure from the analysis and focusing on the pull-through failures alone, the 88% IOPEG and 100% (24/24) SPEG placement success rates were still not significantly different (p = .234) using the 2-tailed Fisher's exact test's alternate hypothesis that the probability of successful placement is different across incision type.

Pull forces were measured in the first 26 patients. Subsequent measurements were not possible due to inadvertent damage to the strain gauge during the course of the study. Results revealed a greater pull force was required in the IOPEG group compared with the PEG group, but this difference did not reach statistical significance (Table II).

	DISCUSSION

Top METHODS RESULTS DISCUSSION

 
The PEG technique originally described in 1980² was a variation of a surgical gastrostomy technique and involved using a dilating skin incision, which was necessary to pull early versions of feeding catheters through the abdominal wall. Commercially available PEG tubes now routinely possess durable, tapered, self-dilating tips, potentially obviating skin incisions during placement, yet the traditional placement technique persists unchanged. This is largely in part to the belief that dilating skin incisions are still needed not only to complete the PEG tube pull-through but also reduce the risk for stomal infection, beliefs that are based more on tradition than objective data.

The idea of proceeding without skin incision stemmed from the senior author's (THB) experience in direct jejunostomy placement whereby the initial site of transillumination and indentation was sometimes lost after an initial incision had already been made. To avoid more than 1 incision, the tube was placed in the usual fashion, with the anticipation of performing a skin incision during the PEG pull-through. It was noted that the tube could be pulled through the abdominal wall and skin easily without requiring an incision and that there was no increased frequency of stomal complications. According to this favorable experience, we proceeded in prospective analyses in hopes of demonstrating that this IOPEG technique is safe. In this previously published pilot of 20 patients, we showed that IOPEG placement was not only feasible with 100% placement success but also appeared to reduce stomal complications compared with historical data.¹³ These pilot results prompted this head-to-head comparison of the 2 placement techniques.

In this prospective, randomized comparison of the 2 techniques, we found that placement success rates were not significantly different between groups and that stomal complications are not increased by incision omission. The latter would indicate that the reduction in stomal infections previously suggested by our pilot study comparison was likely a result of biases due to comparisons to historical data. This prospective data, however, demonstrate that stomal complications (infection, bleeding, pain, satisfaction) do not seem to be directly affected by the inclusion or omission of a dilating skin incision.

Admittedly, a significantly higher percentage of patients in the IOPEG group continued to receive antibiotics for non-PEG indications, which may have added a bias to the stomal infection scores. Also, stomal evaluators were not blinded to the method of tube placement. Despite the fact that no difference was demonstrated between groups at 1 week, a potential third source for possible type II error is the high dropout rate by subjects in both groups for the day-7 stomal evaluation. Every attempt was made to contact these patients, but many had left the local area, making stomal examinations impossible. Additionally, with the median scores for stomal complications at or near zero in all parameters, the validity of the stomal evaluation tool's sensitivity could be questioned, despite the tool's undergoing internal review for content validity. However, the clinical significance of any difference too subtle to be detected is arguable. In contrast, the composite infection scoring system has been previously validated for use in an identical manner in previous publications; thus, the low stomal infections scores seen at day 2 are likely real in our opinion. As pointed out previously, the day-7 infection scores would still be prone to a type II error due to the high dropout rate.

Nonetheless, despite these potential biases, since the completion of this prospective study we have now performed over 100 additional PEG placements (THB, personal experience) without significant infectious complications. Our experience suggests that this incision elimination technique adds no additional time to the procedure, nor has it resulted in any increased frequency of peristomal pressure necrosis. A skin incision is occasionally required (<5%) due to increase pull through forces, and we agree that the pull force required during incisionless PEG tube placement is greater to a degree and that the difference in pullthrough forces demonstrated in this study would likely have reached statistical significance had we been able to complete measurements in all subjects. Despite this, we have experienced no tube separations in this study group or in our subsequent clinical experience with this technique. Although there are no published data on rates of tube breakage during placement, even with the standard technique, a preliminary report by DeLegge and Buck¹⁵ suggests that most manufacturers test their PEG tubes to endure a minimal pull-force of at least 13–15 pounds. Each individual manufacturer's maximal strain limitations, however, are not known as this information is proprietary. However, the success we have experienced using the 20-Fr MIC tube would suggest that with this manufacturer's kit, the increased forces of this modified technique are not clinically significant. According to our experience however, we cannot make any assertions on how PEG tubes from other manufacturer's kits would stand up to this added strain. According to results from our previously published pilot study, there may indeed be different strain limits by kits from other manufacturers. In the rare instance that a separation has occurred, this seems to have been a failure of the string loop where it is attached to the dilating tip of the feeding tube. In these few instances, successful placement was still possible as roughly 1–2 inches of the tubes tip was already passed thought the external abdominal wall and was easily grasped with a hemostat and pull-through completed. Should completion of the pull-though not be possible, the failed tube simply should be removed endoscopically, and a new feeding tube can then be placed either through the previous site ideally or a new site can be selected. The gastric wall defect resulting from a failed PEG placement will spontaneously close within 24 hours and should not require surgical intervention, during which time the patient should remain NPO and the subsequent new gastrostomy tube, or alternatively a nasogastric tube, should be used for gastric decompression.

Due to the wide variations of pull forces encountered with both techniques and the lack of correlation between the absolute pull force and placement failure, we do not advocate the use of adding a strain gauge to PEG placement with either technique. Similarly, when an endoscopist should convert to adding an incision is still subjective. The 5% conversion rate to the traditional technique we report is based on individual endoscopists' comfort with pull forces and the degree of skin tenting encountered in any given patient.

In summary, we have shown incisionless PEG to be safe and effective and question the long-held dogma that a skin incision is required for successful PEG placement and infection prevention. The potential advantages of an incisionless tube placement may be realized by a reduction in bleeding complications in patients requiring anticoagulation (such as CVA). Conceivably, patients requiring anticoagulation (mechanical heart valves) may be able to receive heparin almost immediately after the procedure, though a prospective study would be needed to evaluate this. What is clear, though, is that as endoscopy equipment evolves, our traditional methods and rationale for all endoscopic procedures need to be periodically revisited and revised to take advantage of technology advancements.

Grant support provided by unrestricted grant, BARD Medical.

Top METHODS RESULTS DISCUSSION

 
Poster presentation, ASGE annual scientific meeting, Orlando, FL, 2003.

Received for publication August 26, 2005. Accepted for publication February 1, 2006.

1. Zilling T. Oesophageal surgery: review of its history illustrated by the practice of a single hospital. Eur J Surg.1996; 162:757 –762.[Web of Science][Medline] [Order article via Infotrieve]
2. Gauderer MW, Ponsky JL, Izant RJ. Gastrostomy without laparotomy: a percutaneous endoscopic technique. J Pediatr Surg.1980; 15:872 –875.[Web of Science][Medline] [Order article via Infotrieve]
3. Ponsky JL, Gauderer MW, Stellato TA. Percutaneous endoscopic gastrostomy: review of 150 cases. Arch Surg.1983; 118:913 –914.[Abstract/Free Full Text]
4. Bergstrom LR, Larson DE, Zinsmeister AR, Sarr MG, Silverstein MD. Utilization and outcomes of surgical gastrostomies and jejunostomies in an era of percutaneous endoscopic gastrostomy: a population-based study. Mayo Clin Proc. 1995;70:829 –836.[Abstract]
5. Wollman B, D'Agostino HB, Walus-Wigle JR, Easter DW, Beale A. Radiologic, endoscopic, and surgical gastrostomy: an institutional evaluation and meta-analysis of the literature. Radiology.1995; 197:699 –704.[Abstract/Free Full Text]
6. Calton WC, Gooden SM, Martindale RG. Complications of percutaneous endoscopic gastrostomy. Mil Med.1992; 157:358 –360.[Web of Science][Medline] [Order article via Infotrieve]
7. Moller P, Lindberg CG, Zilling T. Gastrostomy by various techniques: evaluation of indications, outcomes, and complications.Scand J Gastroenterol.1999; 10:1050 –1054.
8. Petersen TI, Kruse A. Complications of percutaneous endoscopic gastrostomy. Eur J Surg.1997; 163:351 –356.[Web of Science][Medline] [Order article via Infotrieve]
9. Duszak R Jr, Mabry MR. National trends in gastrointestinal access procedures: an analysis of Medicare services provided by radiologists and other specialists. J Vasc Interv Radiol.2003; 14:1031 –1036.[Web of Science][Medline] [Order article via Infotrieve]
10. Bosco JJ, Barkun AN, Isenberg GA, et al; ASGE Technology Assessment Committee. Endoscopic enteral nutritional access devices. Gastrointest Endosc. 2002;56:796 –802.[CrossRef][Web of Science][Medline] [Order article via Infotrieve]
11. Ponsky JL. PEG: no minor surgery. Gastrointest Endosc. 1986;32:300 –301.[Web of Science][Medline] [Order article via Infotrieve]
12. Strodel WE, Ponsky JL, Knol JA, Stellato TA, Eckhauser FE, Gauderer MWL. Percutaneous endoscopic gastrostomy. In: Dent TL, Strodel WE, Turlotte JG, eds. Surgical Endoscopy. Chicago, IL: Year Book Medical Publishers; 1985:113 –122.
13. Sedlack R, Pochron N, Baron T. Percutaneous endoscopic gastrostomy placement without a skin incision: results of a prospective pilot study.J Clin Gastroenterol.2003; 37:368 –371.[CrossRef][Web of Science][Medline] [Order article via Infotrieve]
14. Jain NK, Larson DE, Schroeder KW, et al. Antibiotic prophylaxis for percutaneous endoscopic gastrostomy. Ann Intern Med.1987; 107:824 –828.[Abstract/Free Full Text]
15. DeLegge MH, Buck G. Pull forces required for PEG tube placement using the standard Ponsky pull technique [abstract]. Am J Gastroenterol. 2001;96:S52 .

Journal of Parenteral and Enteral Nutrition, Vol. 30, No. 3, 240-245 (2006)
DOI: 10.1177/0148607106030003240


CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Sedlack, R. E. Articles by Baron, T. H. Search for Related Content PubMed PubMed Citation Articles by Sedlack, R. E. Articles by Baron, T. H. Social Bookmarking                   What's this?