Auto-diuresis Predicts Return of Bowel Function.

PURPOSE: Feeding a ventral hernia repair (VHR) patient before the return of bowel function (ROBF) can lead to distention and emesis. Many patients spontaneously diurese after surgery. We hypothesized that this auto-diuresis would signal ROBF. MATERIALS AND METHODS: A total of 395 patients who underwent open, laparoscopic, or mixed VHR were evaluated for correlation between fluid status and ROBF or discharge. ROBF within 24 hours and discharge within 24 hours or 48 hours were used as outcome measures. RESULTS: Patients remained an average 3.59 days after surgery in the hospital and the average ROBF was on day 2.99. The first shift of ≥700 mL of urine predicted ROBF ( P =0.03) and discharge ( P =0.04) within 24 hours. The first shift output of ≥500 mL predicted discharge within 48 hours ( P =0.02). CONCLUSION: Auto-diuresis after surgery is correlated to ROBF and discharge. Accurate fluid measurement can predict bowel function and allow early diet and discharge.

Transversus abdominis plane blocks for complex abdominal wall reconstruction decrease hospital length of stay compared to epidurals.

BACKGROUND: Complex abdominal wall reconstruction for ventral and incisional hernias can be quite painful with prolonged length of stay (LOS). There are a variety of options to manage post-operative pain after a ventral hernia repair, including epidural catheters, transversus abdominis plane (TAP) blocks, and intravenous narcotic pain medications (IVPM). We hypothesized that TAP blocks with liposomal bupivacaine decrease the LOS compared to epidurals and IVPM. METHODS: A retrospective review of all patients who underwent an open ventral hernia repair with retromuscular mesh between 2016 and 2020 was conducted. LOS was used as the primary outcome. Secondary outcomes included post-operative pain and 90-day post-operative complications. RESULTS: An epidural was used in 66 patients, a TAP block with liposomal bupivacaine in 18 patients, and IVPM in 11 patients. The epidural group was noted to have a significantly longer duration of surgery (251.11 vs. 207.94 min; P < 0.05) and larger area of mesh (461.85 vs. 338.17 cm2; P < 0.05) when compared to the TAP block group. Hospital LOS was significantly shorter for the TAP block group compared to the epidural group (4.22 vs. 5.62 days; P < 0.05). There were no differences in post-operative complications between the groups. The epidural group reported significantly lower post-operative day one (POD1) pain scores measured on a 10-point scale, compared to the IVPM and TAP block groups (5.00 vs. 6.91 vs. 7.50; P < 0.05). CONCLUSION: Patients who received a TAP block for post-operative pain management had a significantly shorter length of stay compared to those patients who received an epidural. While the TAP block group reported higher POD1 pain scores, they did not have a significant difference in post-operative complications. TAP blocks with liposomal bupivacaine should be considered for post-operative pain control in complex ventral hernia repairs.

Resident perception of fundamental endoscopic skills exam: a single institution's experience.

BACKGROUND: Graduating general surgery residents are required to pass the FES exam for ABS certification. Trainees and surgery educators are interested in defining the most effective methods of exam preparation. Our aim is to define trainee perceptions, performance, and the most effective preparation methods regarding the FES exam. METHODS: General surgery residents from a single institution who completed the FES exam were identified. All participated in a flexible endoscopy rotation, and all had access to an endoscopy simulator. Residents were surveyed regarding preparation methods and exam difficulty. Descriptive statistics and a Kruskal-Wallis test were used. RESULTS: A total of 26 trainees took the FES exam with a first-time pass rate of 96.2%. Of 26 surveys administered, 21 were completed. Twenty trainees (76.9%) participated in a dedicated endoscopy curriculum. Scores were not different among those who received dedicated curricular instruction compared to those who did not (547 [IQR 539-562.5] vs. 516 [484.5-547], p = 0.1484; 535.5 [468.5-571] vs. 519 [464.75-575], p = 0.9514). Written exam difficulty was rated as 5.5 on a 10-point Likert scale, and 85.7% felt it was a fair assessment of endoscopy knowledge; skills exam difficulty was rated as 7, and 71% felt it was a fair assessment of endoscopy skills. Online FES modules, the endoscopy clinical rotation, and an exam preparation session with a faculty member were most effective for written exam preparation. The most effective skills exam preparation methods were independent simulator practice, the endoscopy clinical rotation, and a preparation session with a faculty member. The most difficult skills were loop reduction and retroflexion. Skill decay did not appear to be significant. CONCLUSIONS: A clinical endoscopy rotation, a method for independent skills practice, and faculty-mediated exam instruction appear to be effective exam preparation methods. When these are present, trainees report minimal need for dedicated exam preparation time prior to taking the FES exam.

Retro-rectus placement of bio-absorbable mesh improves patient outcomes.

BACKGROUND: There is little consensus on the ideal anatomical placement of bio-absorbable mesh. We hypothesized that retro-rectus placement of bio-absorbable mesh would significantly reduce recurrence rates when compared to intraperitoneal mesh placement. METHODS: A retrospective review was conducted of patients who underwent open complex ventral hernia repair using bio-absorbable mesh (Bio-A, Gore, Flagstaff, AZ). Patient demographics and Centers for Disease Control wound type were collected. RESULTS: A total of 81 patients were included. Seventy-four (91.4%) of these hernia repairs had mesh in the retro-rectus position, while 7 (8.6%) had intraperitoneal mesh placement. Patient demographics, including preoperative comorbidities, did not differ between groups. The retro-rectus group trended to have larger hernia defects (156.2 cm2) compared to the intraperitoneal group (63.9 cm2) (p = 0.058). Overall complications (e.g., dehiscence, wound drainage, cellulitis, sepsis) were also similar in both groups of patients. Recurrence rates in the retro-rectus and intraperitoneal group were 8.1% and 42.9%, respectively (p = 0.005). When evaluating only patients with CDC class 1 wounds, the recurrence rate in the retro-rectus group was 8.2% and the intraperitoneal group was 50% (p = 0.02). Overall, the average patient follow-up was 22 months and did not differ between groups. Both the retro-rectus and intraperitoneal groups indicated a significant (p < 0.05) improvement in quality of life from baseline. No long-term (> 7 days) antibiotics were used and no mesh implants were removed during the study. CONCLUSION: Patients who underwent open complex ventral hernia repairs with bio-absorbable mesh in the retro-rectus position experienced lower overall complication rates than those with intraperitoneal mesh placement. Despite a larger hernia defect in the retro-rectus group, recurrence rates were significantly reduced with retro-rectus placement of mesh compared to intraperitoneal placement. In addition, recurrence rates using bio-absorbable mesh in clean wounds are comparable to previously published recurrence rates with permanent mesh.

Individual learning plans foster self-directed learning skills and contribute to improved educational outcomes in the surgery clerkship.

BACKGROUND: The Individual Learning Plan (ILP) is a newly implemented curricular element designed to foster self-directed learning (SDL) skills among medical students during our surgery clerkship. Our aim was to determine the impact of ILPs on educational outcomes and acquisition of SDL skills. METHODS: Students were surveyed regarding the educational value of ILPs, their acquisition of SDL skills, and the impact of the surgery clerkship on fostering these skills. Mean scores for the NBME surgery subject exam (SSE) were compared before and after implementation of the ILP requirement. RESULTS: Students perceived the ILP requirement as having strong educational value. Mean scores for the SSE increased significantly in the year following ILP implementation (74.9 vs 76.6; p = .042; d = 0.21). Students reported successful acquisition and frequent utilization of SDL skills. CONCLUSIONS: SDL exercises, such as the ILP requirement, lead to improved education outcomes while fostering the acquisition of SDL skills.

Improved immediate postoperative pain following laparoscopic inguinal herniorrhaphy using self-adhering mesh.

BACKGROUND: Several synthetic meshes are available to reinforce the inguinal region following laparoscopic hernia reduction. We sought to compare postoperative pain of patients who underwent laparoscopic inguinal herniorrhaphy using self-adhering polyester mesh to those who had non-adhering, synthetic mesh implanted using absorbable tacks. MATERIALS AND METHODS: This study is a retrospective review of patients who underwent primary laparoscopic inguinal herniorrhaphy at the Medical College of Wisconsin between October 2012 and July 2014. Clinical information and perioperative pain scores using the visual analog scale (VAS) were obtained to evaluate immediate pre and postoperative pain. RESULTS: A total of 98 patients (88 male) underwent laparoscopic inguinal herniorrhaphy during the study interval. Forty-two patients received self-adhering mesh and 56 patients received mesh secured with tacks. Patient demographics and comorbidities did not differ significantly between the two groups. There was no difference in preoperative VAS scores between groups. The self-adhering mesh patients had a lower mean VAS change score (less pain). Postoperative complications did not differ between groups apart from a higher observed incidence of seroma in the self-adhering mesh group (p = 0.04). No hernias recurred in either group during the study interval. CONCLUSIONS: Self-adhering mesh in laparoscopic inguinal herniorrhaphy resulted in less immediate postoperative pain than tacked mesh as demonstrated by VAS score. Postoperative complications were similar between the two groups. The results of this study demonstrate that laparoscopic inguinal herniorrhaphy using self-adhering mesh is comparable to tacked mesh in regards to short-term complication rates, but show a favorable advantage in regards to immediate postoperative pain.

Preoperative pain in patient with an inguinal hernia predicts long-term quality of life.

BACKGROUND: Patients presenting for inguinal hernia repair report a wide range of pain. We hypothesized that patients presenting with less preoperative pain would experience a greater improvement in long-term quality of life after an inguinal hernia repair. METHODS: A total of 54 patients underwent either laparoscopic or open inguinal hernia repair and completed the Short Form 12 (SF-12) survey both preoperatively and 6 to 12 months after their repair. The physical and mental component scores (PCS and MCS) were calculated from the SF-12. Patients also completed an analog surgical pain scale. t Tests and analyses of covariance were used. A preoperative surgical pain scale score of >12 was representative of moderate to severe pain. RESULTS: Regardless of preoperative pain, there was improvement in long-term PCS quality of life (45.4 ± 11.3 vs 50.1 ± 9.1; P < .0001) that was not noted when assessing MCS quality of life (55.0 ± 8.3 vs 54.7 ± 9.4; P = .76). Patients who reported no or a low amount of preoperative pain experienced improved PCS quality of life compared with patients who reported moderate to severe preoperative pain (P = .048). This relationship was not noted with MCS (P = .16). CONCLUSION: This study suggests that patients presenting for inguinal hernia repair with no or low pain are more likely to experience improved physical function quality of life as a result of the herniorrhaphy.

Acetazolamide reduces postoperative pain following laparoscopic inguinal herniorrhaphy.

BACKGROUND: Carbonic acid accumulation, which results from CO2 insufflation, can produce visceral and referred pain in the postoperative setting. Acetazolamide inhibits carbonic anhydrase, an enzyme that accelerates carbonic acid formation. We hypothesized that preoperative administration of acetazolamide would decrease postoperative pain in patients undergoing laparoscopic inguinal herniorrhaphy. METHODS: A retrospective review was conducted of patients who underwent laparoscopic preperitoneal inguinal herniorrhaphy at the Medical College of Wisconsin between October 2012 and September 2014. Beginning in January 2014, patients began receiving 250 mg of acetazolamide preoperatively; patients prior to that time did not. The visual analog scale (range 0-10) was used to assess both preoperative pain and postoperative pain. RESULTS: A total of 66 patients underwent laparoscopic inguinal herniorrhaphy during the study interval. Of these, 22 (33 %) patients received acetazolamide preoperatively, and 44 (67 %) were included as controls. Overall mean pain scores were lower in the acetazolamide group (1.9 ± 1.45 vs 2.9 ± 1.5, p = 0.04). Specifically, patients who received acetazolamide reported lower pain scores immediately after surgery (0.6 ± 1.2 vs 1.9 ± 2.3, p = 0.01) and on post-op day one (2.3 ± 0.9 vs 4.0 ± 2.1, p = 0.04). Total morphine equivalents administered to manage postoperative pain were significantly less for the acetazolamide group (4.3 ± 4.8 mg) when compared to the control group (8.9 ± 8.4 mg), p = 0.04. Perioperative complications did not differ between the groups (p = 0.16). CONCLUSIONS: Acetazolamide appears to reduce pain in the immediate postoperative setting. Patients who received acetazolamide had lower pain scores postoperatively and required fewer narcotics for pain management prior to discharge.

Per-Oral Endoscopic Myotomy (POEM) After Previous Laparoscopic Heller Myotomy Is Feasible and Safe in a Porcine Model.

PURPOSE: We sought to evaluate the feasibility, safety, and difficulty of performing the per-oral endoscopic myotomy (POEM) procedure in the setting of a prior Heller myotomy using a survival porcine model. METHODS: Four pigs underwent laparoscopic Heller myotomy with Dor partial anterior fundoplication followed by the POEM performed 4 weeks later. Two additional pigs served as controls, undergoing only the POEM. RESULTS: All procedures were completed without complications. The revisional POEM was not significantly more difficult than POEM controls based on procedure time, POEM procedure components, or procedure difficulty scores. Revisional POEM had a longer mean operative time when compared with Heller myotomy (126.0 vs. 83.8 min; P<0.01) but had a lower total difficulty score (28.6 vs. 52.1; P≪0.01). CONCLUSIONS: A POEM after previous Heller myotomy is safe and feasible in the porcine model and has potential as an option for patients suffering from recurrent or persistent symptoms after failed surgical myotomy.

Surgery duration predicts urinary retention after inguinal herniorrhaphy: a single institution review.

BACKGROUND: Inguinal hernia repair, laparoscopic or open, is one of the most frequently performed operations in general surgery. Postoperative urinary retention (POUR) can occur in 0.2-35 % of patients after inguinal hernia repair. The primary objective of this study was to determine the incidence of POUR after inguinal hernia repair. As a secondary goal, we sought to determine whether perioperative and patient factors predicted urinary retention. METHODS: This study is a retrospective review of patients who underwent inguinal hernia repair with synthetic mesh at the Medical College of Wisconsin from January 2007 to June 2012. Procedures were performed by four surgeons. Clinical information and perioperative outcomes were collected up to hospital discharge. Urinary retention was defined as need for urinary catheterization postoperatively. RESULTS: A total of 192 patients were included in the study (88 bilateral, 46 %) and (104 unilateral, 54 %). The majority of subjects (76 %) underwent laparoscopic repair. The overall POUR rate was 13 %, with 25 of 192 patients requiring a Foley catheter prior to discharge. POUR was significantly associated with bilateral hernia repairs (p = 0.04), BMI ≥ 35 kg/m(2) (p = 0.05) and longer operative times (p = 0.03). Based on odds ratio (OR) estimates, for every 10-min increase in operative time, an 11 % increase in the odds of urinary retention is expected (OR 1.11, CI 1.004-1.223; p = 0.04). For every 10-min increase in operative time, an 11 % increase in POUR is expected. CONCLUSIONS: Bilateral hernia repairs, BMI ≥ 35 kg/m(2), and operative time are significant predictors of POUR. These factors are important to determine potential risk to patients and interventions such as strict fluid administration, use of catheters, and potential premedication.

Postoperative dysphagia is not predictive of long-term failure after laparoscopic antireflux surgery.

INTRODUCTION: Dysphagia is a common postoperative symptom after laparoscopic antireflux surgery, usually attributed to postoperative edema or a "too tight" fundoplication. Although it is usually self-limited, it occasionally requires endoscopic dilation and rarely revisionary surgery. It has not been previously described whether postoperative dysphagia is associated with poorer long-term reflux control after fundoplication. METHODS: We hypothesized that the presence of dysphagia in the early postoperative period is associated with long-term failure of the antireflux procedure and recurrence of gastroesophageal reflux disease (GERD) symptoms. A retrospective review of a prospectively maintained database of patients undergoing antireflux surgery was performed. The study population included patients, who underwent primary laparoscopic Nissen fundoplication between the years 1991 and 2010. The presence of dysphagia on their first postoperative visit (<30 days) was used to classify them in the early-dysphagia (ED) and the no-early-dysphagia (NED) groups. The recurrence of heartburn or regurgitation, as well as the pH studies on long-term follow-up (more than 6 months) were compared between the two groups. A grading system (range 0-4) was used to measure the severity of foregut symptoms. RESULTS: 1223 patients underwent primary laparoscopic Nissen fundoplications during the study period and met the inclusion criteria. Both short and long-term follow-up was available in 821 patients, who were analyzed. 423 patients were included in the ED group, whereas 398 in the NED group. The mean regurgitation score of the ED group on the long-term follow-up was 0.25 compared to 0.20 for the NED group (P = 0.21). The heartburn score was 0.38 for the ED group compared to 0.33 for the NED group (P = 0.38). Long-term dysphagia was higher in the ED group. These findings were confirmed when ED patients were subclassified based on the degree of early post-operative dysphagia. Of the 821 patients, 599 underwent routine postoperative pH testing. The mean DeMeester score in the ED group (n = 308) was 11.7 compared to 13.2 for the NED group (n = 291; P = 0.54). The percentage of patients with abnormal pH testing was similar between the two groups. CONCLUSIONS: Early postoperative dysphagia is not associated with worse long-term GERD symptom control after primary laparoscopic antireflux surgery.

Video. Transanal specimen retrieval using the transanal endoscopic microsurgery (TEM) system in minimally invasive colon resection.

BACKGROUND: During laparoscopic colectomy, the specimen is retrieved through substantial incisions, which increase postoperative pain, wound infections, and incisional hernias. In the era of natural orifice transluminal endoscopic surgery (NOTES), incisionless transrectal approaches for colon resections have been investigated with promising results [4-6]. Transanal retrieval of the colonic specimen in laparoscopic colectomy has been described but not widely adopted, although it seems to be an appealing step towards NOTES colectomy. We have used the TEM rectoscope (Richard Wolf Medical Instruments Corporation, Vernon Hills, IL, USA) as a retrieval conduit, which facilitates transanal extraction of the specimen, and protects the rectal edge and anal sphincter during laparoscopic left colectomy. TECHNIQUE: After standard laparoscopic dissection and vascular control, the colon is divided distally, whereas the proximal colonic end is ligated to prevent fecal spillage. The TEM rectoscope is advanced through the rectal stump. The proximal colon is grasped and withdrawn through the rectoscope. The colon is stapled off proximally, and the specimen is removed transanally. An anvil is introduced into the pelvis through the rectoscope and inserted in the descending colon through a colotomy, which is subsequently sealed with an endo-loop. The rectoscope is withdrawn, and the rectal stump edge is stapled off. A circular stapler is introduced in the rectum, and end-to-end anastomosis is performed. DISCUSSION: The extraction incisions in laparoscopic colectomy increase invasiveness and compromise the "purity" of the laparoscopic approach. Retrieval of the specimen through natural orifices constitutes a stepping stone in the transition to future incisionless NOTES colectomy. These techniques have not been widely adopted because of technical difficulties and concerns regarding trauma. In our experience, transanal retrieval of the colonic specimen is hampered by friction between the specimen and the rectum, which requires countertraction to the edges of the open rectal stump. These manipulations are time consuming and increase the risk of injury, even when retrieval bags are used. The TEM rectoscope allows gentle dilation of the anus, provides stability during extraction, and protects the edges of the rectum, therefore decreasing the risk of rectal or anal canal injuries. It maintains pneumoperitoneum and eases retrieval of the specimen through the large-caliber metal conduit. Alternative options in the form of a rigid conduit would be the use of the transanal endoscopic operation device (Karl Storz, Tuttlingen, Germany), the plastic McCartney tube (Tyco Healthcare, Norwalk, CT, USA) used for transvaginal operations, or an anecdotally reported, "homemade" rectoscope from a customized polyvinyl chloride tube. Potential limitations of this technique include the increased cost of acquiring and using the TEM rectoscope, although this should not be significant if this reusable system is already available for transanal procedures. The 4 cm diameter of the TEM rectoscope can also be a limiting factor in the case of large, bulky, incompressible specimens or large colonic tumors. We have also avoided using this technique in patients with preexisting anal sphincter dysfunction and fecal incontinence, as well as in the presence of severe perianal disease (i.e., fistulae or fissures). Naturally, the open lumen in the peritoneal cavity raises concerns regarding bacterial contamination and potential tumor cell seeding in cases of cancer. Preliminary evidence on these issues comes from TEM and NOTES research without obvious signs of increased risk currently. We do not perform preoperative bowel preparation for our colectomies, but we do perform rectal enema with Betadine solution at the beginning of the procedure. CONCLUSIONS: Use of the TEM system facilitates transanal removal of the specimen and protects the anorectum during laparoscopic colectomy.

Ancestral bias in the Hras1 gene and distal Chromosome 7 among inbred mice.

Inbred strains of mice vary in their frequency of liver tumors initiated by a mutation in the Hras1 (H-ras) proto-oncogene. We sequenced 4.5 kb of the Hras1 gene on distal Chr 7 in a diverse set of 12 commonly used laboratory inbred strains of mice and detected no sequence variation to account for strain-specific differences in Hras1 mutation prevalence. Furthermore, the Hras1 sequence is essentially monoallelic for an ancestral gene derived from the M. m. domesticus species. To determine if the monoallelism and associated low rate of polymorphism are unique to Hras1 or representative of the general chromosomal locale, we extended the sequence analysis to 12 genes in the final 8 Mb of distal Chr 7. A region of at least 2.5 Mb that encompasses several genes, including Hras1 and the H19/Igf2 loci, demonstrates virtually no sequence variation. The 12 inbred strains share one dominant haplotype derived from the M. m. domesticus allele. Chromosomal regions flanking the monoallelic segment exhibit a significantly higher rate of variation and multiple haplotypes, a majority of which are attributed to M. m. domesticus or M. m. musculus ancestry.