Fluorescence Angiography in Colorectal Resection.

BACKGROUND: Intraoperative laser fluorescence angiography is a relatively new tool that can be used by colorectal surgeons to ensure adequate perfusion to bowel that remains after resection. It has been used mostly to determine an appropriate point of transection of the proximal bowel, as well as to ensure perfusion after the anastomosis has been constructed. We propose a different use of the technology in complex cases to ensure the ability to safely transect a major vascular pedicle and to ensure that perfusion will remain adequate. OBJECTIVE: The purpose of this article is to describe a new use for fluorescence angiography technology. DESIGN: This is a technical note. SETTINGS: The work was conducted at a tertiary care military medical center. PATIENTS: Patients included individuals requiring oncologic colorectal resection where the status of 1 major vascular pedicle was unknown or impaired. MAIN OUTCOME MEASURES: We assessed perfusion after occlusion of a major vascular pedicle for the short term in hospital outcomes. RESULTS: Adequate studies were obtained, and perfusion was maintained in both patients. Oncologic resections were performed, and short-term outcomes were comparable with any individual undergoing these procedures. LIMITATIONS: This study was limited because it is early experience that was not performed in the setting of a scientific investigation. CONCLUSIONS: Application of intraoperative fluorescence angiography in this setting appears to be safe and may assist the surgeon in estimating reliable vascular perfusion in patients such as these who require oncologic colorectal resection.

Biomaterials in the treatment of anal fistula: hope or hype?

Anal fistula (AF) presents a chronic problem for patients and colorectal surgeons alike. Surgical treatment may result in impairment of continence and long-term risk of recurrence. Treatment options for AFs vary according to their location and complexity. The ideal approach should result in low recurrence rates and minimal impact on continence. New technical approaches involving biologically derived products such as biological mesh, fibrin glue, fistula plug, and stem cells have been applied in the treatment of AF to improve outcomes and decrease recurrence rates and the risk of fecal incontinence. In this review, we will highlight the current evidence and describe our personal experience with these novel approaches.

Cefazolin-induced neutropenia and thrombocytopenia following trauma: a case report.

Cefazolin, a first generation cephalosporin, is a rare cause of cyclical fevers, neutropenia, and thrombocytopenia following surgical prophylaxis. We present the case of an otherwise healthy 21-year-old male who sustained a 50-cm laceration to his chest and abdomen. He received emergency department prophylaxis with cefazolin and surgical repair. Subsequently, he developed cyclical fevers, neutropenia, and thrombocytopenia, all of which resolved after antibiotic discontinuation. This is the first case report in which the perioperative administration of cefazolin following trauma resulted in significant neutropenia and thrombocytopenia. Also discussed in this report are the etiology, workup, and treatment of cefazolin-induced neutropenia.

Nestin reporter transgene labels multiple central nervous system precursor cells.

Embryonic neuroepithelia and adult subventricular zone (SVZ) stem and progenitor cells express nestin. We characterized a transgenic line that expresses enhanced green fluorescent protein (eGFP) specified to neural tissue by the second intronic enhancer of the nestin promoter that had several novel features. During embryogenesis, the dorsal telencephalon contained many and the ventral telencephalon few eGFP+ cells. eGFP+ cells were found in postnatal and adult neurogenic regions. eGFP+ cells in the SVZ expressed multiple phenotype markers, glial fibrillary acidic protein, Dlx, and neuroblast-specific molecules suggesting the transgene is expressed through the lineage. eGFP+ cell numbers increased in the SVZ after cortical injury, suggesting this line will be useful in probing postinjury neurogenesis. In non-neurogenic regions, eGFP was strongly expressed in oligodendrocyte progenitors, but not in astrocytes, even when they were reactive. This eGFP+ mouse will facilitate studies of proliferative neuroepithelia and adult neurogenesis, as well as of parenchymal oligodendrocytes.

Examining Utility of Routine Splenic Flexure Mobilization during Colectomy and Impact on Anastomotic Complications.

BACKGROUND: Despite a lack of supporting data, routine splenic flexure mobilization (SFM) during colectomy has been thought to reduce anastomotic leak (AL). We evaluated the impact of SFM on outcomes in distal colectomy. STUDY DESIGN: The 2005-2016 NSQIP database identified 66,068 patients undergoing distal colectomy with anastomosis. Cohorts were stratified by addition of SFM. Postoperative outcomes were compared between groups. Regression analysis identified factors affecting odds of developing AL. RESULTS: SFM was performed in 27,475 patients (41.6%). There was no difference in overall complications between cases with SFM and those without (p = 0.55). SFM had longer operative times (220 min vs. 184 min; p < 0.0001). SFM was not associated with any difference in AL rate (3.6% vs. 3.7%; p = 0.86). Factors most associated with AL were lack of oral antibiotic preparation (OR 1.93; p < 0.001), chemotherapy (OR 1.91; p < 0.001), and weight loss (OR 1.68; p = 0.0005). Operative indication and approach did not affect leak. CONCLUSIONS: SFM in distal colectomy increased operative time without decreasing overall complications or AL. Routine splenic flexure mobilization may add risk without significant benefit.

Colonoscopy after Hinchey I and II left-sided diverticulitis: utility or futility?

BACKGROUND: Modern 64- to 128-slice computed tomography (CT) scanners have questioned the need for routine colonoscopy after hospital admission for presumed uncomplicated diverticulitis. METHODS: This is a retrospective review of all patients (>18 years) who underwent planned colonoscopy after admission for Hinchey I or II acute diverticulitis (January 2009 to January 2014). The findings on the final radiologist report were then correlated with the colonoscopy results. RESULTS: In total, 110 patients (mean age, 55.2 ± 16; 46.4% female) underwent a subsequent colonoscopy (median, 60 days) after admission for diverticulitis. Overall, 102 patients (92.7%) had CT findings consistent with definitive diverticulitis, 6 patients had a diagnosis suggestive of diverticulitis on CT scan, and 2 patients had masses on their admission CT scans. Within the group with definitive diverticulitis, follow-up colonoscopy identified diverticulosis in 99 (97.0%), whereas the other 3 had normal findings. Of the patients with CT scans suggestive of diverticulitis, follow-up colonoscopy showed 3 with diverticulosis, 2 with malignancies, and 1 with nonspecific inflammation. The reliability of CT scans for diverticulitis compared with colonoscopy was found to have a kappa = .829 (P < .001; 95% confidence interval, .629, 1.21). CONCLUSIONS: Follow-up colonoscopy should be performed when a CT scan suggests malignancy, nonspecific inflammatory findings, or the patient is otherwise due for routine screening or surveillance. In this study, there was no benefit of follow-up colonoscopy in patients with CT-confirmed diverticulitis in the absence of other concerning or indeterminate findings.

Subventricular zone neuroblasts emigrate toward cortical lesions.

Adult subventricular zone (SVZ) neuroblasts migrate in the rostral migratory stream to the olfactory bulbs. Brain lesions generally increase SVZ neurogenesis or gliogenesis and cause SVZ cell emigration to ectopic locations. We showed previously that glia emigrate from the SVZ toward mechanical injuries of the somatosensory cerebral cortex in mice. Here we tested the hypotheses that SVZ neurogenesis increases, that neuroblasts emigrate, and that epidermal growth factor expression increases after cortical injuries. Using immunohistochemistry for phenotypic markers and BrdU, we show that newborn doublecortin-positive SVZ neuroblasts emigrated toward cerebral cortex lesions. However, the number of doublecortin-positive cells in the olfactory bulbs remained constant, suggesting that dorsal emigration was not at the expense of rostral migration. Although newborn neuroblasts emigrated, rates of SVZ neurogenesis did not increase after cortical lesions. Finally, we examined molecules that may regulate emigration and neurogenesis after cortical lesions and found that epidermal growth factor was increased in the SVZ, corpus callosum, and cerebral cortex. These results suggest that after injuries to the cerebral cortex, neuroblasts emigrate from the SVZ, that emigration does not depend either on redirection of SVZ cells or on increased neurogenesis, and that epidermal growth factor may induce SVZ emigration.

Mesenteric irritation as a means to prevent internal hernia formation after laparoscopic gastric bypass surgery.

INTRODUCTION: Internal hernias (IHs) occur more frequently in laparoscopic gastric bypass (LGB) surgery than in the classic open procedure. The incidence of small bowel obstruction after LGB ranges from 1.8% and 9.7%. Some have theorized that this occurs because of decreased adhesion formation. METHODS: The mesenteric irritation technique is performed after closure of the jejunojejunal mesenteric defect with a running 2-0 silk suture. A sponge is then rubbed against the closed visceral peritoneal mesentery until petechiae are visualized on the surface of the mesentery. RESULTS: In all, 338 LGBs were performed using the standard closure technique with an IH incidence of 5.3% (range 1.7% to 7.8%). When using the mesenteric irritation technique, 72 LGBs were performed with an IH rate of 1.4% (P = .13). CONCLUSIONS: Mesenteric irritation is a novel technique performed with minimal additional time and no additional equipment. This technique may prove beneficial in reducing the incidence of IHs.

The weekend effect: does time of admission impact management and outcomes of small bowel obstruction?

AIMS: To determine whether day and time of admission influences the practice patterns of the admitting general surgeon and subsequent outcomes for patients diagnosed with small bowel obstruction. METHODS: A retrospective database review was carried out, covering patients admitted with the presumed diagnosis of partial small bowel obstruction from 2004-2011. RESULTS: A total of 404 patients met the inclusion criteria. One hundred and thirty-nine were admitted during the day, 93 at night and 172 on the weekend. Overall 30.2% of the patients were managed operatively with no significant difference between the groups (P = 0.89); however, of patients taken to the operating room, patients admitted during the day received operative intervention over 24 hours earlier than those admitted at a weekend, 0.79 days vs 1.90 days, respectively (P = 0.05). Overall mortality was low at 1.7%, with no difference noted between the groups (P = 0.35). Likewise there was no difference in morbidity rates between the three groups (P = 0.90). CONCLUSIONS: Despite a faster time to operative intervention in those patients admitted during the day, our study revealed that time of admission does not appear to correlate to patient outcome or mortality.

Future directions for monitoring treatment response in colorectal cancer.

Treatment of advanced colon and rectal cancer has significantly evolved with the introduction of neoadjuvant chemoradiation therapy so much that, along with more effective chemotherapy regimens, surgery has been considered unnecessary among some institutions for select patients. The tumor response to these treatments has also improved and ultimately has been shown to have a direct effect on prognosis. Yet, the best way to monitor that response, whether clinically, radiologically, or with laboratory findings, remains controversial. The authors' aim is to briefly review the options available and, more importantly, examine emerging and future options to assist in monitoring treatment response in cases of locally advanced rectal cancer and metastatic colon cancer.

Future directions for the early detection of colorectal cancer recurrence.

Surgical resection remains a mainstay of treatment and is highly effective for localized colorectal cancer. However, ~30-40% of patients develop recurrence following surgery and 40-50% of recurrences are apparent within the first few years after initial surgical resection. Several variables factor into the ultimate outcome of these patients, including the extent of disease, tumor biology, and patient co-morbidities. Additionally, the time from initial treatment to the development of recurrence is strongly associated with overall survival, particularly in patients who recur within one year of their surgical resection. Current post-resection surveillance strategies involve physical examination, laboratory, endoscopic and imaging studies utilizing various high and low-intensity protocols. Ultimately, the goal is to detect recurrence as early as possible, and ideally in the asymptomatic localized phase, to allow initiation of treatment that may still result in cure. While current strategies have been effective, several efforts are evolving to improve our ability to identify recurrent disease at its earliest phase. Our aim with this article is to briefly review the options available and, more importantly, examine emerging and future options to assist in the early detection of colon and rectal cancer recurrence.

An evaluation of colonoscopy surveillance guidelines: are we actually adhering to the guidelines?

BACKGROUND: National guidelines put forth by the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Gastroenterology provide recommendations regarding colorectal cancer screening and follow-up surveillance. Practice patterns may differ from these guidelines. This study analyzes the concordance between a tertiary equal access system and national guidelines for colorectal cancer and polyp surveillance. METHODS: We performed a retrospective database review of all patients at a single institution undergoing screening colonoscopy from 2010 to 2011. Patient demographics, indication for colonoscopy, pathologic findings, and follow-up recommendations documented by the provider were analyzed. Multivariate analysis was performed in an attempt to identify predictors of discordant recommendations. RESULTS: One thousand four hundred twenty patients were identified (mean age, 54.3 ± 7.7 years, 48.6% women). The gastroenterology service performed the majority of colonoscopies (87.2%) compared with the surgery service (11.6%). The major indications were routine screening (84.4%) and a strong family history of colorectal cancer (12.2%). The adenoma detection rate for the entire cohort was 27.4%. Other pathologic conditions identified included hyperplastic polyps (16%), lymphoid aggregates (3.5%), and invasive adenocarcinoma (0.1%). Overall, follow-up recommendations correlated with established guidelines in 97% of cases. By multivariate analysis, only the final pathologic finding of lymphoid aggregates was associated with discordant recommendations (odds ratio [OR], 4.62; 95% confidence interval [CI], 1.64 to 12.99; P = .004). When comparing discordant recommendations between specialties, there was a statistically significant difference between gastroenterology (1.6%) and surgery (7.6%) (P < .0001) providers; surgeons trended toward recommending earlier follow-up examinations (P = .37). CONCLUSIONS: Overall, surveillance recommendations correlated well with current national guidelines. Concordance rates were higher with gastroenterologists in this cohort. Alterations based on final pathologic examination and individual cases remain clinically important.

Radial glia-like cells at the base of the lateral ventricles in adult mice.

During development radial glia (RG) are neurogenic, provide a substrate for migration, and transform into astrocytes. Cells in the RG lineage are functionally and biochemically heterogeneous in subregions of the brain. In the subventricular zone (SVZ) of the adult, astrocyte-like cells exhibit stem cell properties. During examination of the response of SVZ astrocytes to brain injury in adult mice, we serendipitously found a population of cells in the walls of the ventral lateral ventricle (LV) that were morphologically similar to RG. The cells expressed vimentin, glial fibrillary acidic protein (GFAP), intermediate filament proteins expressed by neural progenitor cells, RG and astrocytes. These RG-like cells had long processes extending ventrally into the nucleus accumbens, ventromedial striatum, ventrolateral septum, and the bed nucleus of the stria terminalis. The RG-like cell processes were associated with a high density of doublecortin-positive cells. Lesioning the cerebral cortex did not change the expression of vimentin and GFAP in RG-like cells, nor did it alter their morphology. To study the ontogeny of these cells, we examined the expression of molecules associated with RG during development: vimentin, astrocyte-specific glutamate transporter (GLAST), and brain lipid-binding protein (BLBP). As expected, vimentin was expressed in RG in the ventral LV embryonically (E16, E19) and during the first postnatal week (P0, P7). At P14, P21, P28 as well as in the adult (8-12 weeks), the ventral portion of the LV retained vimentin immunopositive RG-like cells, whereas RG largely disappeared in the dorsal two-thirds of the LV. GLAST and BLBP were expressed in RG of the ventral LV embryonically and through P7. In contrast to vimentin, at later stages BLBP and GLAST were found in RG-like cell somata but not in their processes. Our results show that cells expressing vimentin and GFAP (in the radial glia-astrocyte lineage) are heterogeneous dorsoventrally in the walls of the LV. The results suggest that not all RG in the ventral LV complete the transformation into astrocytes and that the ventral SVZ may be functionally dissimilar from the rest of the SVZ.

Distribution of doublecortin expressing cells near the lateral ventricles in the adult mouse brain.

Doublecortin (Dcx) is a microtubule-associated protein expressed by migrating neuroblasts in the embryo and in the adult subventricular zone (SVZ). The adult SVZ contains neuroblasts that migrate in the rostral migratory stream (RMS) to the olfactory bulbs. We have examined the distribution and phenotype of Dcx-positive cells in the adult mouse SVZ and surrounding regions. Chains of Dcx-positive cells in the SVZ were distributed in a tight dorsal population contiguous with the RMS, with a separate ventral population comprised of discontinuous chains. Unexpectedly, Dcx-positive cells were also found outside of the SVZ: dorsally in the corpus callosum, and ventrally in the nucleus accumbens, ventromedial striatum, ventrolateral septum, and bed nucleus of the stria terminalis. Dcx-positive cells outside the SVZ had the morphology of migrating cells, occurred as individual cells or in chain-like clusters, and were more numerous anteriorly. Of the Dcx-positive cells found outside of the SVZ, 47% expressed the immature neuronal protein class III beta-tubulin, 8% expressed NeuN, a marker of mature neurons. Dcx-positive cells did not express molecules found in astrocytes, oligodendrocytes, or microglia. Structural and immunoelectron microscopy revealed that cells with the ultrastructural features of neuroblasts in the SVZ were Dcx+, and that clusters of neuroblasts emanated ventrally from the SVZ into the parenchyma. Our results suggest that the distribution of cells comprising the walls of the lateral ventricle are more heterogeneous than was thought previously, that SVZ cells may migrate dorsally and ventrally away from the SVZ, and that some emigrated cells express a neuronal phenotype.