Clinical practice guidelines for enhanced recovery after colon and rectal surgery from the American Society of Colon and Rectal Surgeons and the Society of American Gastrointestinal and Endoscopic Surgeons

The American Society of Colon and Rectal Surgeons (ASCRS) and the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) are dedicated to ensuring high-quality innovative patient care for surgical patients by advancing the science, prevention, and management of disorders and diseases of the colon, rectum, and anus as well as minimally invasive surgery. The ASCRS and SAGES society members involved in the creation of these guidelines were chosen because they have demonstrated expertise in the specialty of colon and rectal surgery and enhanced recovery. This consensus document was created to lead international efforts in defining quality care for conditions related to the colon, rectum, and anus and develop clinical practice guidelines based on the best available evidence. While not proscriptive, these guidelines provide information on which decisions can be made and do not dictate a specific form of treatment. These guidelines are intended for the use of all practitioners, healthcare workers, and patients who desire information about the management of the conditions addressed by the topics covered in these guidelines. These guidelines should not be deemed inclusive of all proper methods of care nor exclusive of methods of care reasonably directed toward obtaining the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all the circumstances presented by the individual patient. This clinical practice guideline represents a collaborative effort between the American Society of Colon and Rectal Surgeons (ASCRS) and the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) and was approved by both societies.

Understanding colorectal twitter: A comparison of its highest and lowest rank influencers

The distribution of content related to colorectal surgery in social media is steadily increasing. Social media influencers possess large audiences and are frequently viewed as authority; however, their credibility is often unchecked. In our commentary we present our analysis and comparison of the most and least influential accounts on Twitter within the field of colorectal surgery. Additionally, we discuss the current literature, role and importance of social media for the modern surgeon.

Elevation of Serum CEA in Patients with Squamous Cell Carcinoma of the Anus

The proportion of anal cancer cases that produce elevated carcinoembryonic antigen (CEA) levels is not well described in the medical literature. In this study, we used electronic health record data from a single urban cancer center to identify patients from 2004-2018 with anal cancer who have also had a pre-initial treatment CEA measurement. We identified 40 patients who met our eligibility criteria. Of those, 11 (27.5%) had an elevated pretreatment CEA. Elevated CEA was not associated with any of the clinical or demographic covariates; however, three out of five patients with a recurrence had an elevated CEA.

Correction to: Anal canal squamous cell cancer: are surgical alternatives to chemoradiation just as effective?

One of the author's middle name of this article was incorrectly published as "Emmanouil E. Pappou." This is now presented correctly in this article as "Emmanouil P. Pappou."

Obesity, regardless of comorbidity, influences outcomes after colorectal surgery-time to rethink the pay-for-performance metrics?

An elevated body mass index (BMI) is associated with increased morbidity and mortality after colorectal surgery. While coexistent comorbid conditions are captured in some determinations of case-severity, BMI itself is not factored into pay for performance (P4P) initiatives. From the National Surgical Quality Improvement Program database 2006-2011, obese (BMI ≥30 kg/m(2)) and nonobese (BMI <30 kg/m(2)) patients with and without comorbidity undergoing colorectal resection were identified. Pre- and intraoperative factors as well as postoperative outcomes were compared. Of 130,415 patients, 31.3 % were obese. 80.4 % of obese and 72.9 % of nonobese patients had comorbid conditions. Among obese patients, overall rates of surgical site infection (SSI), wound dehiscence, and various medical complications were significantly higher for those with comorbidity compared to those without (p < 0.001 for all). Obese patients with comorbidity overall had greater risk of renal failure and urinary tract infection than nonobese patients. Regardless of comorbidity, obese patients more commonly had pulmonary embolism, failure to wean from the ventilator, overall SSI, and wound dehiscence. Comorbid factors associated with obesity influence outcomes; however, obesity itself in their absence is associated with worse outcomes. This supports inclusion of obesity as an independent determinant of case-severity, quality, and reimbursement after colorectal surgery.

Incidence and predictors of bowel obstruction in elderly patients with stage IV colon cancer: a population-based cohort study

IMPORTANCE

Research has been limited on the incidence, mechanisms, etiology, and treatment of symptoms that require palliation in patients with terminal cancer. Bowel obstruction (BO) is a common complication of advanced abdominal cancer, including colon cancer, for which small, single-institution studies have suggested an incidence rate of 15% to 29%. Large population-based studies examining the incidence or risk factors associated with BO in cancer are lacking.

OBJECTIVE

To investigate the incidence and risk factors associated with BO in patients with stage IV colon cancer.

DESIGN AND SETTING

Retrospective cohort, population-based study of patients in the Surveillance, Epidemiology, and End Results and Medicare claims linked databases who were diagnosed as having stage IV colon cancer from January 1, 1991, through December 31, 2005.

PATIENTS

Patients 65 years or older with stage IV colon cancer (n = 12 553).

MAIN OUTCOMES AND MEASURES

Time to BO, defined by inpatient hospitalization for BO. We used Cox proportional hazards regression models to determine associations between BO and patient, prior treatment, and tumor features.

RESULTS

We identified 1004 patients with stage IV colon cancer subsequently hospitalized with BO (8.0%). In multivariable analysis, proximal tumor site (hazard ratio, 1.22 [95% CI, 1.07-1.40]), high tumor grade (1.34 [1.16-1.55]), mucinous histological type (1.27 [1.08-1.50]), and nodal stage N2 (1.52 [1.26-1.84]) were associated with increased risk of BO, as was the presence of obstruction at cancer diagnosis (1.75 [1.47-2.04]). A more recent diagnosis was associated with decreased risk of subsequent obstruction (hazard ratio, 0.84 [95% CI, 0.72-0.98]).

CONCLUSIONS AND RELEVANCE

In this large population of patients with stage IV colon cancer, BO after diagnosis was less common (8.0%) than previously reported. Risk was associated with site and histological type of the primary tumor. Future studies will explore management and outcomes in this serious, common complication.

Colorectal cancer in patients under 50 years of age: A retrospective analysis of two institutions' experience

AIM: To investigate the epidemiological characteristics of colorectal cancer (CRC) in patients under 50 years of age across two institutions.

METHODS: Records of patients under age 50 years of age who had CRC surgery over a 16 year period were assessed at two institutions. The following documents where reviewed: admission notes, operative notes, and discharge summaries. The main study variables included: age, presenting symptoms, family history, tumor location, operation, stage/differentiation of disease, and post operative complications. Stage of disease was classified according to the American Joint Committee on Cancer TNM staging system: tumor depth; node status; and metastases.

RESULTS: CRC was found in 180 patients under age 50 years (87 females, 93 males; mean age 41.4 ± 6.2 years). Young patients accounted for 11.2% of cases during a 6 year period for which the full data set was available. Eight percent had a 1^st degree and 12% a 2^nd degree family CRC history. Almost all patients (94%) were symptomatic at diagnosis; common symptoms included: bleeding (59%), obstruction (9%), and abdominal/rectal pain (35%). Evaluation was often delayed and bleeding frequently attributed to hemorrhoids. Advanced stage CRC (Stage 3 or 4) was noted in 53% of patients. Most tumors were distal to the splenic flexure (77%) and 39% involved the rectum. Most patients (95%) had segmental resections; 6 patients had subtotal/total colectomy. Poorly differentiated tumors were noted in 12% and mucinous lesions in 19% of patients of which most had Stage 3 or 4 disease. Twenty-two patients (13%) developed recurrence and/or progression of disease to date. Three patients (ages 42, 42 and 49 years) went on to develop metachronous primary colon cancers within 3 to 4 years of their initial resection.

CONCLUSION: CRC was common in young patients with no family history. Young patients with symptoms merit a timely evaluation to avoid presentation with late stage CRC.

Management and outcomes of bowel obstruction in patients with stage IV colon cancer: a population-based cohort study

BACKGROUND

Bowel obstruction is a common complication of late-stage abdominal cancer, especially colon cancer, which has been investigated predominantly in small, single-institution studies.

OBJECTIVE

We used a large, population-based data set to explore the surgical treatment of bowel obstruction and its outcomes after hospitalization for obstruction among patients with stage IV colon cancer.

DESIGN

This was a retrospective cohort study.

SETTING AND PATIENTS

We identified 1004 patients aged 65 years or older in the Surveillance, Epidemiology and End Results-Medicare database diagnosed with stage IV colon cancer January 1, 1991 to December 31, 2005, who were later hospitalized for bowel obstruction.

MAIN OUTCOME MEASURES

We describe outcomes after hospitalization and analyzed the associations between surgical treatment of obstruction and outcomes.

RESULTS

Hospitalization for bowel obstruction occurred a median of 7.4 months after colon cancer diagnosis, and median survival after obstruction was approximately 2.5 months. Median hospitalization for obstruction was about 1 week and in-hospital mortality was 12.7%. Between discharge and death, 25% of patients were readmitted to the hospital at least once for obstruction, and, on average, patients lived 5 days out of the hospital for every day in the hospital between obstruction diagnosis and death. Survival was 3 times longer in those whose obstruction claims suggested an adhesive obstruction origin. In multivariable models, surgical compared with nonsurgical management was not associated with prolonged survival (p = 0.134).

LIMITATIONS

Use of an administrative database did not allow determination of quality of life or relief of obstruction as an outcome, nor could nonsurgical interventions, eg, endoscopic stenting or octreotide, be assessed.

CONCLUSIONS

In this population-based study of patients with stage IV colon cancer who had bowel obstruction, overall survival following obstruction was poor irrespective of treatment. Universally poor outcomes suggest that a diagnosis of obstruction in the setting of advanced colon cancer should be considered a preterminal event.

Bowel obstruction in elderly ovarian cancer patients: a population-based study

PURPOSE

Bowel obstruction is a common pre-terminal event in abdominal/pelvic cancer that has mainly been described in small single-institution studies. We used a large, population-based database to investigate the incidence, management, and outcomes of obstruction in ovarian cancer patients.

PATIENTS AND METHODS

We identified patients with stages IC-IV ovarian cancer, aged 65 years or older, in the Surveillance, Epidemiology and End Results (SEER)-Medicare database diagnosed between January 1, 1991 and December 31, 2005. We modeled predictors of inpatient hospitalization for bowel obstruction after cancer diagnosis, categorized management of obstruction, and analyzed the associations between treatment for obstruction and outcomes.

RESULTS

Of 8607 women with ovarian cancer, 1518 (17.6%) were hospitalized for obstruction subsequent to cancer diagnosis. Obstruction at cancer diagnosis (HR=2.17, 95%CI: 1.86-2.52) and mucinous tumor histology (HR=1.45, 95%CI: 1.15-1.83) were associated with increased risk of subsequent obstruction. Surgical management of obstruction was associated with lower 30-day mortality (13.4% in women managed surgically vs. 20.2% in women managed non-surgically), but equivalent survival after 30 days and equivalent rates of post-obstruction chemotherapy. Median post-obstruction survival was 382 days in women with obstructions of adhesive origin and 93 days in others.

CONCLUSION

In this large-scale, population-based assessment of patients with advanced ovarian cancer, nearly 20% of women developed bowel obstruction after cancer diagnosis. While obstruction due to adhesions did not signal the end of life, all other obstructions were pre-terminal events for the majority of patients regardless of treatment.

Oncologic colorectal resection, not advanced endoscopic polypectomy, is the best treatment for large dysplastic adenomas

INTRODUCTION

Endoscopic submucosal dissection (ESD), endoscopic mucosal resection (EMR), and partial circumference resection are used for large benign polyps to avoid an "Oncologic" Colorectal Resection (OCR); polyps with invasive cancer require OCR. This review of polyp patients who had OCR was done to stratify polyps into risk groups to guide treatment.

METHODS

Colonoscopy, operative, and pathology reports of patients with adenoma (+/- dysplasia) who had OCR were reviewed. Polyp size, location, and pathology were assessed.

RESULTS

Three hundred eighty-six polyp patients who had OCR were studied. Polyp locations were: right, 263 (68.1%); transverse, 33 (8.6%); sigmoid, 38 (9.8%); rectum, 23 (6.0%); and multiple sites, 13 (3.4%). The preoperative diagnosis was adenoma for 288 (74.6%) and dysplastic adenoma for 98 patients (25.4%). Final pathology revealed 62 invasive cancers (16.1%); 35% (34 out of 98) with dysplasia preoperatively had cancer versus 9.7% (28 out of 288) with adenoma alone (p < 0.0001). The mean lymph node count was 16.0 ± 10.2. Cancer stage breakdown was: stage 1, 74%; stage 2, 8.1%; stage 3, 16%; and stage 4, 1.6%. The mean benign polyp size was 3.0 ± 1.9 versus 3.9 ± 2.4 cm for malignant polyps (p = 0.0008).

CONCLUSION

Over one out of three of dysplastic polyps and 10% of adenomas were invasive cancers. OCR is advised for dysplastic polyps; ESD, EMR, and wedge resection are appropriate for non-dysplastic adenomas.

Minimally invasive colon resection is associated with a persistent increase in plasma PlGF levels following cancer resection

BACKGROUND

Minimally invasive colorectal resection (MICR) is associated with persistently elevated plasma VEGF levels that may stimulate angiogenesis in residual tumor foci. Placenta growth factor (PlGF) stimulates neovascularization in tumors by modulating VEGF's effects. This study's purpose was to determine the impact of MICR on blood PlGF levels in cancer patients (Study A) and to compare PreOp levels in patients with cancer and benign (BEN) disease (Study B).

METHODS

Blood samples were collected preoperatively, on postoperative day (POD) 1, POD 3, and at various time points 2-4 weeks after surgery. Samples from 7-day periods after POD 6 were bundled to allow analysis. Plasma PlGF levels were determined via ELISA, results reported as mean±SD, and data analyzed via t test. Significance was set at p<0.008 after Bonferroni correction.

RESULTS

Study A: 76 colorectal cancer (CRC) patients had MICR (laparoscopic, 59%; hand-assisted, 41%). The mean length of stay was 5.8±2.1 days. The mean PreOp PlGF level was 15.4±4.3 pg/ml. Significantly increased levels were noted on POD 1 (25.8±7.7 pg/ml, p<0.001), POD 3 (22.9±6.7, p<0.001), POD 7-13 (19.2±5.1, p<0.001), and POD 14-20 (19.5±6.7, p<0.002). The mean POD 21-27 level was not significantly different from baseline. Study B included 126 CRC and 111 BEN patients. PreOp levels were higher in the CRC patients (15.6±5.3 pg/ml) than in the BEN group (13.5±5.5 pg/ml, p=0.001).

CONCLUSIONS

PlGF levels are elevated for 3 weeks after MICR and PreOp plasma levels are higher in CRC patients than in BEN disease patients. The cause of the postoperative increase is unclear. The persistently higher blood levels of PlGF and VEGF after MICR may stimulate angiogenesis in residual tumor foci. Further studies regarding late blood protein alterations after surgery appear to be indicated.

Is there a role for a strict incision length criterion for determining conversions during laparoscopic colorectal resection?

PURPOSE

There's no consensus about what defines a conversion for laparoscopic-assisted colorectal resection (LACR). This study's goal was to assess the utility of a strict incision length (IL) definition of conversion (incision > 7 cm) and compare it with results obtained when the surgeon determined (SD) if a LACR had been successfully completed.

METHODS

The demographic and perioperative data for 580 elective LACRs were reviewed. The short-term outcomes for each conversion definition were determined and compared.

RESULTS

Conversion rates were 22% using the IL definition and 16% via the SD method. Both methods detected significant differences between completed and converted groups regarding the following: incision size, hospital stay, time to flatus, bowel movement, and regular diet as well as rate of wound infection and ileus. The IL method alone detected significant differences in the rate of pulmonary complications and BMI between the completed and converted groups.

CONCLUSIONS

The 2 methods yielded similar results for most parameters. The IL method better separated the patients in regard to 2 parameters. This method is objective and easy to apply; however, it may discriminate against obese patients whose extraction incisions are often longer. A conversion definition that considers BMI and IL is needed.

High incidence of technical errors involving the EEA circular stapler: a single institution experience

BACKGROUND

The use of stapling devices is now widespread in colorectal resections. However, the incidence and clinical consequence of technical error involving the circular stapler are still poorly characterized.

STUDY DESIGN

We reviewed the operative reports and Web-based charts for all colon and rectal resections performed at our institution that used a circular stapler. Technical error was defined as any deviation from the normal technical performance of the circular stapler, including, but not limited to, surgeon misfiring, incomplete anastomosis (inadequate donuts or staple line defects), and primary device failure. The unpaired t- and chi-square tests were used for statistical analysis; p < 0.05.

RESULTS

There were 349 colorectal resections performed and 67 (19%) featured a technical error. Thirty-two resections (9%) included an anastomotic error. The control group (n = 282) and the error group (n = 67) were comparable with regard to leaks, reoperation, suture line strictures, and hospital stay. The malfunction group had higher incidences of proximal diversions (34% versus 16%; p = 0.0003), ileus (24% versus 8%; p = 0.002), gastrointestinal bleeding (4% versus 0.4%; p = 0.023), and transfusion requirements (13% versus 4%; p = 0.004). Although proximal diversions in the error cohorts were also less likely to be planned (p < 0.001), reversal rates were similar in both groups (p = 0.28).

CONCLUSIONS

The incidence of technical error involving the circular stapler is considerable. Technical error was found to be associated with a significantly higher risk of gastrointestinal bleeding, transfusions, and unplanned proximal diversions.

Prospective study of ambulation after open and laparoscopic colorectal resection

PURPOSE

Open and laparoscopic surgical approaches each have specific advantages. This study compares ambulation, hospital length of stay (LOS), and incision length after open and laparoscopic colorectal resection.

METHODS

All consecutive patients undergoing colorectal resection over a 2 year period ending August 2002 were followed prospectively. Ambulation, LOS, and incision length were recorded. Hybrid low anterior resection (LAR) patients had laparoscopic splenic flexure takedown, vessel ligation, and proximal rectal mobilization followed by planned inferior laparotomy to complete the case. Groups were compared using Student's t test.

RESULTS

Equivalent open and laparoscopic groups were comparable in terms of gender, age, body mass index, ASA class, indication for operation, and resection performed. Seventy open colectomy patients were compared with 99 laparoscopic-assisted colectomy patients. On average, patients in the open and laparoscopic groups ambulated 67 and 390 feet, respectively, on postoperative day 1 (P < .001), 290 and 752 feet on day 2 (P < .001), and 495 and 965 feet on day 3 (P < .001). The average LOS in the open group was 9.3 days compared with 5.9 days in the laparoscopic group (P < .001). The average incision length in the open group was 19.7 cm compared with 5.3 cm in the laparoscopic group (P < .001). Seventeen open LAR patients were compared with 30 hybrid LAR patients. On average, patients in the open and hybrid groups ambulated 22 and 150 feet, respectively, on postoperative day 1 (P = .003), 105 and 433 feet on day 2 (P = .003), and 369 and 488 feet on day 3 (P = .43). The average LOS in the open group was 10 days compared with 8.5 days in the hybrid group (P = .46). The average incision length in the open group was 19.8 cm compared with 10.8 cm in the hybrid group (P < .001). When all 216 patients were considered, the 91 patients with incisions shorter than 8 cm (average 4.6 cm) ambulated 396, 752, and 956 feet on consecutive days whereas the 125 patients with incisions 8 cm or longer (average 16.9 cm, P < .001) ambulated 101, 334, and 521 feet on consecutive days (all P values <.001). Average LOS in the <8-cm group was 6 days compared with 8.9 days in the > or =8-cm group (P < .001).

CONCLUSIONS

Patients undergoing minimal-access colorectal surgery ambulated significantly further than equivalent open patients in the early postoperative period and had a shorter LOS.

A case of portal venous gas after extracorporeal shockwave lithotripsy and obstructive pyelonephritis

The presence of gas in the portal venous system is considered an ominous sign often mandating immediate exploratory laparotomy; however, there are numerous reports of benign incidences of this finding. This report describes a case of portal venous gas after extracorporeal shockwave lithotripsy. The patient had the rare complication of obstructive pyleonephritis that progressed to sepsis and subsequently underwent a negative exploratory laparotomy. It is suggested that the radiographic finding of portal venous gas should be correlated with the likely cause and overall clinical picture.

Major abdominal surgery increases plasma levels of vascular endothelial growth factor: open more so than minimally invasive methods

INTRODUCTION

Vascular endothelial growth factor (VEGF) is a potent inducer of angiogenesis that is necessary for wound healing and also promotes tumor growth. It is anticipated that plasma levels would increase after major surgery and that such elevations may facilitate tumor growth. This study's purpose was to determine plasma VEGF levels before and early after major open and minimally invasive abdominal surgery.

METHODS

Colorectal resection for cancer (n = 139) or benign pathology (n = 48) and gastric bypass for morbid obesity (n = 40) were assessed. Similar numbers of open and laparoscopic patients were studied for each indication. Plasma samples were obtained preoperatively and on postoperative days (POD) 1 and 3. VEGF levels were determined via ELISA. The following statistical methods were used: Fisher exact test, unmatched Student t test, Wilcoxon's matched pairs test, and the Mann Whitney U Test with P < 0.05 considered significant.

RESULTS

The mean preoperative VEGF level of the cancer patients was significantly higher than baseline level of benign colon patients. Regardless of indication or surgical method, on POD3, significantly elevated mean VEGF levels were noted for each subgroup. In addition, on POD1, open surgery patients for all 3 indications had significantly elevated VEGF levels; no POD1 differences were noted for the closed surgery patients. At each postoperative time point for each procedure and indication, the open group's VEGF levels were significantly higher than that of the matching laparoscopic group. VEGF elevations correlated with incision length for each indication.

CONCLUSION

As a group colon cancer patients prior to surgery have significantly higher mean VEGF levels than patients without tumors. Also, both open and closed colorectal resection and gastric bypass are associated with significantly elevated plasma VEGF levels early after surgery. This elevation is significantly greater and occurs earlier in open surgery patients. The duration and clinical importance of this finding is uncertain but merits further study.

Perioperative immunomodulation with Flt3 kinase ligand or a whole tumor cell vaccine is associated with a reduction in lung metastasis formation after laparotomy in mice

INTRODUCTION

Laparotomy has been associated with temporary postoperative immunosuppression and accelerated tumor growth in experimental models. In a previous murine study, a whole cell vaccine plus the adjuvant monophosphoryl-lipid A was shown to be effective in decreasing the number of lung metastases that develop after laparotomy. This study was conducted to assess the impact of the adjuvant fetal liver tyrosine kinase 3 (Flt3) ligand on perioperative tumor growth when used alone or with a tumor cell vaccine.

METHODS

An intravenous tumor cell injection lung metastases model was used. Sixty female A/J mice were divided into six equal groups designated (1) anesthesia control (AC), (2) AC with Flt3 ligand (ACFlt3), (3) sham laparotomy (OP), (4) OP with Flt3 ligand (OPFlt3), (5) OP with vaccine (OPVac), and (6) OP with Flt3 ligand and vaccine (OPFlt3Vac). Groups 2, 4, and 6 received daily intraperitoneal injections of Flt3 ligand (10 microg/dose with carrier) for 5 days before and 5 days after surgery. Groups 1 and 3 received similar injections of saline on the same schedule. Groups 5 and 6 were vaccinated with irradiated whole Ta3Ha tumor cells intraperitoneally three times before and twice after surgery. Immediately after surgery, all mice were injected with 10(5) Ta3Ha tumor cells via a tail vein. After 14 days, the mice were sacrificed and their lungs and tracheas were excised en bloc. Specimens were stained and counterstained with India ink and Fekete solution, and surface metastases were counted by a blinded observer. Differences between study groups were determined by analysis of variance. The peritumoral inflammatory cell infiltrate of some Flt3 and control specimens was also assessed.

RESULTS

Regarding laparotomy, Flt3 ligand (mean, 1.22 metastases), whole cell vaccine (1.12 metastases), and the combination of these two agents (0.1 metastases) were each effective in significantly decreasing the number of surface lung metastases compared with surgery alone (9.88 metastases, P < .05 for all comparisons). There were no differences between the various treatment groups in regards to number of metastases. Only the combination of Flt3 and the vaccine significantly lowered the incidence of tumors (number of mice with > or =1 tumors). Histologic analysis revealed that the Flt3-treated mice demonstrated increased numbers of antigen-presenting cells surrounding the tumors compared with controls.

CONCLUSIONS

Perioperative treatment with either Flt3 ligand or a whole cell tumor vaccine significantly reduced the number of lung metastases after laparotomy. The combination of the Flt3 ligand and the vaccine also decreased the incidence of metastases and was the most effective treatment. Further studies regarding perioperative immune modulation in the setting of cancer appear warranted.

Significant reduction of laparotomy-associated lung metastases and subcutaneous tumors after perioperative immunomodulation with flt3 ligand in mice

Laparotomy has been associated with increased rates of tumor establishment and metastasis formation postoperatively in animal models. The purpose of this study was to determine the impact on postoperative tumor growth of perioperative upregulation of immune function via fetal liver tyrosine kinase 3 (Flt3 ligand). Two murine studies were carried out: the first utilized a lung metastases model, and the second involved a subcutaneous tumor model. Each study included four groups: anesthesia control (AC), AC plus Flt3 ligand (ACFlt3), sham laparotomy (OP), and OP plus Flt3 ligand (OPFlt3). Flt3 ligand was administered by daily intraperitoneal injection (10 mug/dose) beginning 5 days preoperatively and continuing for 1 week postoperatively. In study 1, A/J mice were given tail vein injections of 1.5 x 10(5) TA3Ha cancer cells on the day of surgery. The mice were sacrificed 14 days after surgery, the lungs processed, and the surface metastases counted by a blinded observer. In study 2 C3H/He mice were given a dorsal subcutaneous injection of 10(4) MC-2 cancer cells on the day of surgery. The mice were sacrificed 31 days after surgery, and the injection sites were evaluated for subcutaneous tumors grossly and histologically. In study 1, the median number of surface lung metastases per mouse was 166 in the OP group and 38 in the OPFlt3 (P = .021). Mice in the AC group developed a median 50 lung metastases per animal compared with mice in the ACFlt3 group who had a median of 10 metastases per mouse (P = .001). The OP group had significantly more metastases than the AC group (P = .048). In study 2, the percentage of animals that developed tumors in the AC, OP, ACFlt3, and OPFlt3 groups was 43, 80, 0, and 20, respectively. The incidence of tumors in the OPFLt3 group and the ACFlt3 group was significantly less than their respective control groups (P < .01). The difference between the OP and AC groups was not significant (P > .05). Perioperatively administered Flt3 ligand was associated with significantly fewer lung metastases and a lower incidence of subcutaneous tumor formation after laparotomy and anesthesia alone. Perioperative immunomodulation may limit untoward surgery-related oncologic effects.

Does hemodynamic instability predict positive technetium-labeled red blood cell scintigraphy in patients with acute lower gastrointestinal bleeding? A review of 50 patients

PURPOSE

Technetium-99m-labeled red blood cell scintigraphy, commonly used in the evaluation of acute lower gastrointestinal hemorrhage, often fails to demonstrate a source of bleeding. It would be helpful to characterize a subset of patients more likely to have a positive scan. This study was undertaken to determine whether hemodynamic instability can predict tagged red blood cell scan positivity.

METHODS

The records of 50 consecutive patients who underwent tagged red blood cell scanning for the evaluation of acute lower gastrointestinal bleeding were reviewed retrospectively.

RESULTS

Patients presenting with a heart rate >100 beats per minute or a systolic blood pressure <100 mmHg up to 24 hours before undergoing tagged red blood cell scanning were considered hemodynamically unstable. Thirteen of 21 unstable patients (62 percent) had positive scans, whereas only 6 of 29 stable patients (21 percent) had positive scintigraphy (odds ratio, 6; 95 percent confidence interval, 1.79-22.1).

CONCLUSIONS

Hemodynamic instability in the setting of acute lower gastrointestinal bleeding may be a predictor of positive tagged red blood cell scanning. Incorporating this into the diagnostic algorithm used to evaluate patients with acute lower gastrointestinal bleeding may allow physicians to reserve red blood cell scintigraphy for patients who have demonstrated transient hemodynamic compromise.

Safety and reliability of tattooing colorectal neoplasms prior to laparoscopic resection

Accurate tumor localization is critical to performing minimally invasive colorectal resection. This study reviews the safety and reliability of tattooing colorectal neoplasms prior to laparoscopic resection. We retrospectively reviewed 50 consecutive patients with colorectal neoplasms who underwent endoscopic tattooing prior to laparoscopic resection. Data were obtained from medical charts, endoscopy records, and pathology reports. No complications related to endoscopy or tattooing were incurred. Five neoplasms (10%) were in the ascending colon, five (10%) were in the transverse colon, eight (16%) were in the descending colon, 23 (46%) were in the sigmoid colon, and nine (18%) were in the rectum. Tattoos were visualized intraoperatively and accurately localized the neoplasm in 44 patients (88%). Six patients (12%) did not have tattoos visualized laparoscopically and required intraoperative localization. On average, the pathology specimens in this series had a 15 cm proximal margin, a 12 cm distal margin, and 15 lymph nodes. In the context of laparoscopic colorectal resection, preoperative endoscopic tattooing is a safe and reliable method of tumor localization in most cases. Localizing colon and proximal rectal lesions with tattoos may be preferable to other localization techniques including intraoperative endoscopy.

Laparoscopic-assisted cecectomy is associated with decreased formation of postoperative pulmonary metastases compared with open cecectomy in a murine model

BACKGROUND

It was shown in a murine model that sham laparotomy is associated with a higher incidence of postoperative lung metastases when compared with results seen after carbon dioxide pneumoperitoneum. Using the same tumor model, the present study was undertaken to determine if the addition of bowel resection to the operative procedure would impact the results.

METHODS

Sixty mice underwent anesthesia alone (anesthesia control [AC]), laparoscopic-assisted cecectomy (LC), or open cecectomy (OC). After surgery, all animals received tail vein injections of 105 TA3-Ha tumor cells. On postoperative day 14, the lungs and trachea were excised en bloc and processed, and surface lung metastases were counted and recorded by a blinded observer.

RESULTS

The mean number of surface lung metastases in the AC, LC, and OC groups was 30.9, 76.3, and 134.5, respectively. Significantly more metastases were documented after OC (P<.001) and LC (P<.05) than after anesthesia alone. Mice in the LC group had significantly fewer lung metastases (43% less) than mice in the OC group (P<.01).

CONCLUSIONS

OC was associated with significantly more lung metastases than either LC or AC. Surgery-related immune suppression or trophic tumor cell stimulation occurring after surgery may contribute to this phenomenon.

Peritoneal macrophage and blood monocyte functions after open and laparoscopic-assisted cecectomy in rats

BACKGROUND

It has been well established that open abdominal surgery results in systemic immunosuppression postoperatively; in contrast, laparoscopic surgery is associated with significantly better preserved systemic immune function. However, when intraperitoneal (local) immune function is considered, laparoscopic procedures done under a CO2 pneumoperitoneum (pneumo) have been shown to result in greater immunosuppression compared to that of open surgery. Few studies have simultaneously assessed systemic and local immune function. The purpose of this study was to assess peripheral blood mononuclear cell (PBMC) and peritoneal macrophage tumor necrosis factor-alpha (TNF-alpha) levels, H2O2 production, and MHC class II antigen expression after open and laparoscopically assisted cecectomy in a rat model.

METHODS

A total of 75 Sprague Dawley rats were used for three separate experiments. For each study, rats were randomly divided into three groups: anesthesia alone (AC), laparoscopic-assisted cecectomy (LC), and open cecectomy via full laparotomy (OP). A CO2 pneumo was used for laparoscopic operations. On postoperative day 1 the animals were sacrificed, macrophages were harvested via intraperitoneal lavage, and PBMCs were isolated from whole blood obtained by cardiac puncture. In experiment 1, macrophages and PBMC from each animal were stimulated with lipopolysaccharide, after which TNF-alpha levels of the supernatant were determined. In experiment 2, after stimulation with PMA, H2O2 release was assessed by measuring fluorescence. In experiment 3, via flow cytometry, the number of cells with surface MHC class II proteins were determined. Data from the three groups in each experiment were compared using analysis of variance Tukey-Kramer tests.

RESULTS

Macrophages and PBMC from rats in the OP group released significantly more TNF-alpha than cells from rats in the LC ( p < 0.05) or AC ( p < 0.05) groups. Macrophages from rats in the OP group released significantly less H2O2 than cells from the AC ( p < 0.01) and LC ( p < 0.05) groups. There was no difference between the AC and LC results. No significant differences in PBMC H2O2 release were noted among any of the groups. OP group macrophages expressed significantly less MHC class II antigen than did AC group macrophages ( p < 0.05). No differences were noted among the LC results and either the OP or AC group's outcomes. No differences were noted in PBMC MHC class II expression among any of the groups.

CONCLUSIONS

In all instances, the LC group's macrophage results were similar to the AC group's results. OC group macrophages produced significantly more TNF-alpha and less H2O2 than both the AC and LC groups. MHC class II protein expression was less for the OC group than for the AC group. OC group PBMCs produced more TNF-alpha. No differences in PBMC H2O2 release or MHC class II expression were noted. Laparoscopic methods better preserves the baseline values of the parameters studied.

Colorectal cancer surveillance after age 65 years

BACKGROUND

It would be valuable to determine whether or not asymptomatic patients 60 to 65 years of age with normal colonoscopies should continue to undergo serial colorectal cancer surveillance examinations.

METHODS

Data were obtained from retrospective review of our existing database. Additional data were obtained from patients' medical records, office charts, and pathology reports. In situ endoscopic measurements were performed using a biopsy forceps that was 7 mm when fully extended.

RESULTS

Over the past 25 years, 699 asymptomatic patients between 60 and 65 years of age underwent colonoscopies which revealed no pathology. As part of their routine continuing colorectal surveillance and without any prior abnormal endoscopic findings, 56 of these patients underwent a total of 123 colonoscopies after age 65. Thirty-seven patients (66%) had surveillance colonoscopies that continued to be normal while 13 patients (23%) were diagnosed with colorectal adenomas and 6 patients (11%) were found to have hyperplastic polyps. No cancers were discovered.

CONCLUSIONS

Patients over the age of 65 should continue to undergo colorectal surveillance even if prior examinations have been negative.

Persistent post-laparoscopy pneumoperitoneum

BACKGROUND

Persistent pneumoperitoneum after a laparoscopic operation can represent either residual postoperative pneumoperitoneum or free intraperitoneal gas released from the gastrointestinal tract. This animal study was conducted to better characterize the extent and duration of postoperative pneumoperitoneum as detected by computed tomography (CT).

METHODS

Five pigs underwent cholecystectomy, four laparoscopically and one open. All pigs were followed serially with upright chest radiographs and abdominal CT scans beginning immediately postoperatively and continuing daily until resolution of pneumoperitoneum as detected by both imaging modalities. All radiographs and CT scans were reviewed by dedicated radiologists who reported the extent and duration of pneumoperitoneum in a blinded fashion.

RESULTS

Pneumoperitoneum resolved on upright chest radiographs in all five pigs by or on postoperative day 1. Serial CT scans demonstrated that the laparoscopic group had either resolution of pneumoperitoneum or minimal persistence of free intraperitoneal gas by postoperative day 2. In contrast, the single pig in the open group had CT evidence of persistent pneumoperitoneum through postoperative day 6.

CONCLUSIONS

In the pig model, small pockets of free intraperitoneal gas detected by CT scanning are expected to resolve by postoperative day 2 following laparoscopic surgery. Persistence of pneumoperitoneum beyond this interval is abnormal and may represent a perforated viscus. Whereas a prospective CT imaging study in humans is not ethically feasible, we believe that parallel conclusions between the pig and human may be drawn.

Ultrasound and sestamibi scan as the only preoperative imaging tests in reoperation for parathyroid adenomas

BACKGROUND

In an effort to determine an efficient algorithm for the evaluation of patients with parathyroid adenomas in the reoperative setting, we explored the combination of using ultrasound scans (US) and sestamibi scintigraphy as the only preoperative imaging tests.

METHODS

We analyzed the outcomes of 62 consecutive patients who were treated between January 1995 and May 1999 and who were referred for persistent primary hyperparathyroidism after initial surgical exploration, at which time no abnormal parathyroid glands had been found. Although all patients underwent US, computed tomography scan, magnetic resonance imaging, and sestamibi scan, we analyzed the success of localization and reoperation using only the results of US and sestamibi scan.

RESULTS

Sixty-one patients (98%) underwent curative reoperations. The sensitivity, positive predictive value, and accuracy for US were 90%, 86%, and 84%, respectively; the corresponding values for sestamibi imaging were 78%, 94%, and 74%, respectively. In 58 of 62 cases (94%) preoperative US and/or sestamibi scan accurately identified the adenoma. In 3 patients for whom combined US and sestamibi scan were inaccurate, 1 adenoma was found by intraoperative US in the strap muscle; 1 adenoma was found by blind cervical thymectomy, and 1 adenoma was found by planned sternotomy that was based on computed tomography findings.

CONCLUSIONS

This study supports an algorithm of obtaining US and sestamibi scan as the initial and perhaps only preoperative localization tests for patients with primary hyperparathyroidism after failed operation, at which time no abnormal glands had been found.