Protective ileostomy creation after anterior resection of the rectum: Shared decision-making or still subjective?

AIM: The choice of whether to perform protective ileostomy (PI) after anterior resection (AR) is mainly guided by risk factors (RFs) responsible for the development of anastomotic leakage (AL). However, clear guidelines about PI creation are still lacking in the literature and this is often decided according to the surgeon's preferences, experiences or feelings. This qualitative study aims to investigate, by an open-ended question survey, the individual surgeon's decision-making process regarding PI creation after elective AR. METHOD: Fifty four colorectal surgeons took part in an electronic survey to answer the questions and describe what usually led their decision to perform PI. A content analysis was used to code the answers. To classify answers, five dichotomous categories (In favour/Against PI, Listed/Unlisted RFs, Typical/Atypical, Emotions/Non-emotions, Personal experience/No personal experience) have been developed. RESULTS: Overall, 76% of surgeons were in favour of PI creation and 88% considered listed RFs in the question of whether to perform PI. Atypical answers were reported in 10% of cases. Emotions and personal experience influenced surgeons' decision-making process in 22% and 49% of cases, respectively. The most frequently considered RFs were the distance of the anastomosis from the anal verge (96%), neoadjuvant chemoradiotherapy (88%), a positive intraoperative leak test (65%), blood loss (37%) and immunosuppression therapy (35%). CONCLUSION: The indications to perform PI following rectal cancer surgery lack standardization and evidence-based guidelines are required to inform practice. Until then, expert opinion can be helpful to assist the decision-making process in patients who have undergone AR for adenocarcinoma.

Laparoscopic Intracorporeal Anastomosis.

Given the progression of laparoscopic surgery, questions continue to arise as to the ideal technique for a laparoscopic colectomy. The most debated of these questions is whether it is best to complete an intracorporeal (ICA) or extracorporeal (ECA) intestinal anastomosis. Here, we review the literature to date and report the equivalent safety and efficacy of ICA and ECA for laparoscopic right colectomy. However, these studies also indicate that when completed, ICA may prove beneficial with respect to earlier return of bowel function, less postoperative pain, shorter incision length, and reduced risk of wound infections. For this, we present the tips and tricks for completing all forms of laparoscopic ICAs during laparoscopic colectomy.

Same day discharge following elective, minimally invasive, colorectal surgery : A review of enhanced recovery protocols and early outcomes by the SAGES Colorectal Surgical Committee with recommendations regarding patient selection, remote monitoring, and successful implementation.

BACKGROUND: As enhanced recovery programs (ERPs) have continued to evolve, the length of hospitalization (LOS) following elective minimally invasive colorectal surgery has continued to decline. Further refinements in multimodal perioperative pain management strategies have resulted in reduced opioid consumption. The interest in ambulatory colectomy has dramatically accelerated during the COVID-19 pandemic. Severe restrictions in hospital capacity and fear of COVID transmission forced surgical teams to rethink strategies to further reduce length of inpatient stay. METHODS: Members of the SAGES Colorectal Surgery Committee began reviewing the emergence of SDD protocols and early publications for SDD in 2019. The authors met at regular intervals during 2020-2022 period reviewing SDD protocols, safe patient selection criteria, surrogates for postoperative monitoring, and early outcomes. RESULTS: Early experience with SDD protocols for elective, minimally invasive colorectal surgery suggests that SDD is feasible and safe in well-selected patients and procedures. SDD protocols are associated with reduced opioid use and prescribing. Patient perception and experience with SDD is favourable. For early adopters, SDD has been the natural evolution of well-developed ERPs. Like all ERPs, SDD begins in the office setting, identifying the correct patient and procedure, aligning goals and objectives, and the perioperative education of the patient and their supporting significant others. A thorough discussion with the patient regarding expected activity levels, oral intake, and pain control post operatively lays the foundation for a successful application of SDD programs. These observations may not apply to all patient populations, institutions, practice types, or within the scope of an existing ERP. However, if the underlying principles of SDD can be incorporated into an existing institutional ERP, it may further reduce the incidence of post operative ileus, prolonged LOS, and improve the effectiveness of oral analgesia for postoperative pain management and reduced opioid use and prescribing. CONCLUSIONS: The SAGES Colorectal Surgery Committee has performed a comprehensive review of the early experience with SDD. This manuscript summarizes SDD early results and considerations for safe and stepwise implementation of SDD with a specific focus on ERP evolution, patient selection, remote monitoring, and other relevant considerations based on hospital settings and surgical practices.

Diverted versus undiverted restorative proctocolectomy for chronic ulcerative colitis: an analysis of long-term outcomes after pouch leak short title: outcomes after pouch leak.

BACKGROUND: The safety of undiverted restorative proctocolectomy (RPC) is debated. This study compares long-term outcomes after pouch leak in diverted and undiverted RPC patients. METHODS: Data were obtained from a prospectively maintained registry from a single surgical practice. One-stage and staged procedures with an undiverted pouch were considered undiverted pouches; all others were considered diverted pouches. The outcomes measured were pouch excision and long-term diversion defined as the need for loop ileostomy at 200 weeks after pouch creation. Regression models were used to compare outcomes. RESULTS: There were 317 diverted and 670 undiverted pouches, of which 378 were one-stage procedures. Pouch leaks occurred in 135 patients, 92 (13.7%) after undiverted, and 43 (13.6%) after diverted pouches. Eighty-six (64%) leaks were diagnosed within 6 months of pouch creation. Undiverted patients underwent more emergent procedures within 30 days of pouch creation (p < 0.01). Pouch excision occurred in 14 (33%) diverted patients and 13 (14%) undiverted patients (p = 0.01). Thirteen (32%) diverted patients and 18 (21%) undiverted patients (p = 0.17) had ileostomies at 200 weeks after surgery. In multivariable analyses, diverted patients had a higher risk of pouch excision (HR 3.67 p < 0.01), but similar rates of ileostomy at 200 weeks (HR 1.8, p = 0.19) compared to undiverted patients. CONCLUSIONS: Despite a likely selection bias in which "healthier" patients undergo an undiverted pouch, our data suggest that diversion does not prevent pouch excision and the need for long-term diversion after pouch leak. These findings suggest that undiverted RPC is a safe procedure in appropriately selected patients.

Fistula-Associated Anorectal Cancer in the Setting of Crohn's Disease.

BACKGROUND: Cancer arising from perianal fistulas in patients with Crohn's disease is rare. There are only a small series of articles that describe sporadic cases of perianal cancer in Crohn's disease fistulas. Therefore, there are no clear guidelines on how to appropriately screen patients at risk and choose proper management. OBJECTIVE: The purpose of this study was to describe patients diagnosed with cancer in perianal fistulas in the setting of Crohn's disease. DESIGN: The study involved an institutional review board-approved retrospective review of medical charts of patients with perianal Crohn's disease. The data extracted from patient charts included demographic and clinical characteristics. SETTINGS: Patients seen at the Mount Sinai Medical Center were included. PATIENTS: We identified patients who were diagnosed with perianal cancer in biopsies of fistula tracts. MAIN OUTCOME MEASURES: We observed the number of patients with Crohn's disease who had fistulas, cancer in fistula tract, and time to diagnosis. RESULTS: The charts of 2382 patients with fistulizing perianal Crohn's disease were reviewed. Cancer in a fistula tract was diagnosed in 19 (0.79%) of these patients, 9 with squamous-cell carcinoma and 10 with adenocarcinoma. The majority of the 19 patients (68%) had symptoms typical of perianal fistula. The mean time from diagnosis of Crohn's disease to fistula diagnosis and from fistula diagnosis to cancer diagnosis was 19.4 and 6.0 years. In 5 patients (26%), cancer was not diagnosed in the first biopsy obtained from the fistula tract. LIMITATIONS: This is a retrospective chart review of a rare outcome; the results may not be generalizable. CONCLUSIONS: Routine biopsies of long-standing fistula tracts in patients with Crohn's disease should be strongly considered and may yield an earlier diagnosis of cancer in the fistula tracts.

The First Study Evaluating the Safety of Pre-Surgery Administration of Metformin in Patients with Colorectal and other Gastrointestinal Cancers and Effect on Cancer Stem Cells.

BACKGROUND: The cancer stem cell (CSC) hypothesis of tumor genesis suggests that unlike most cancer cells within tumor CSC resist chemotherapy and can regenerate various cell types in tumor thereby causing relapse. Hence drugs that selectively target CSC may offer great promise for cancer therapy especially when combined with chemotherapy. Current treatment options for colorectal cancer (CRC) and other gastrointestinal (GI) tumors rely on combination of surgical resection, cytotoxic and targeted drugs. Recent findings showed that metformin, an ant diabetic drug was associated with a significantly lower risk of CRC (0.63 [0.47 - 0.84]; P = 0.002) in patients with type 2 diabetes. We therefore hypothesize that administration of metformin will reduce CSC. METHODS: Patients with CRC and other GI cancers undergoing resection were enrolled. Metformin was administered at 500 mg orally twice daily for up to 14 days and terminated 24 hours, prior to planned surgery. Both tumor and normal tissue was procured. Adverse events (AEs) were graded according to NCI CTCAE Version 3.0. Primary objective was to establish the safety of administering metformin prior to resection. Secondary objective was to evaluate the effects of metformin on the expression of CSC markers by measuring relative mRNA levels of CD133, OCT4 and NANOG by RT-PCR and immunohistochemistry. RESULTS: A total of 10 patients (4 Male; 6 Female) received metformin. Grade 3 AEs included anemia, hypoalbuminemia, alanine aminotransferase elevation, abdominal pain and nausea but none of these were related to metformin. No hypoglycemia and lactic acidosis were observed. No unexpected post-operative complications were witnessed. Comparison of markers of CCSC results showed that expression of CD133, OCT4 and NANOG expression were decreased following metformin. CONCLUSIONS: Our pilot study showed feasibility of metformin before surgery in GI cancers and indicated impact on CSC. This preliminary data warrants further investigation in a larger randomized placebo-control study to assess these markers and their correlation with survival.

How to report educational videos in robotic surgery: an international multidisciplinary consensus statement.

The swift endorsement of the robotic surgical platform indicates that it might prevail as the preferred technique for many complex abdominal and pelvic operations. Nonetheless, use of the surgical robotic system introduces further layers of complexity into the operating theatre necessitating new training models. Instructive videos with relevant exposition could be optimal for early training in robotic surgery and the aim of this study was to develop consensus guidelines on how to report a robotic surgery video for educational purposes to achieve high quality educational video outputs that could enhance surgical training. A steering group prepared a Delphi survey of 46 statements, which was distributed and voted on utilising an electronic survey tool. The selection of committee members was designed to include representative surgical trainers worldwide across different specialties, including lower and upper gastrointestinal surgery, general surgery, gynaecology and urology. 36 consensus statements were approved and classified in seven categories: author's information and video introduction, case presentation, demonstration of the surgical procedure, outcomes of the procedure, associated educational content, review of surgical videos quality and use of surgical videos in educational curricula. Consensus guidelines on how to report robotic surgery videos for educational purposes have been elaborated utilising Delphi methodology. We recommend that adherence to the guidelines presented could support advancing the educational quality of video outputs when designed for training.

Regulation of reactive oxygen species by p53: implications for nitric oxide-mediated apoptosis.

Nitric oxide (NO) induces vascular smooth muscle cell (VSMC) apoptosis in part through activation of p53. Traditionally, p53 has been thought of as the gatekeeper, determining if a cell should undergo arrest and repair or apoptosis following exposure to DNA-damaging agents, depending on the severity of the damage. However, our laboratory previously demonstrated that NO induces apoptosis to a much greater extent in p53(-/-) compared with p53(+/+) VSMC. Increased reactive oxygen species (ROS) within VSMC has been shown to induce VSMC apoptosis, and recently it was found that the absence of, or lack of, functional p53 leads to increased ROS and oxidative stress within different cell types. This study investigated the differences in intracellular ROS levels between p53(-/-) and p53(+/+) VSMC and examined if these differences were responsible for the increased susceptibility to NO-induced apoptosis observed in p53(-/-) VSMC. We found that p53 actually protects VSMC from NO-induced apoptosis by increasing antioxidant protein expression [i.e., peroxiredoxin-3 (PRx-3)], thereby reducing ROS levels and cellular oxidative stress. We also observed that the NO-induced apoptosis in p53(-/-) VSMC was largely abrogated by pretreatment with catalase. Furthermore, when the antioxidant protein PRx-3 and its specific electron acceptor thioredoxin-2 were silenced within p53(+/+) VSMC with small-interfering RNA, not only did these cells exhibit greater ROS production, but they also exhibited increased NO-induced apoptosis similar to that observed in p53(-/-) VSMC. These findings suggest that ROS mediate NO-induced VSMC apoptosis and that p53 protects VSMC from NO-induced apoptosis by decreasing intracellular ROS. This research demonstrates that p53 has antioxidant functions in stressed cells and also suggests that p53 has antiapoptotic properties.

Insulin enhances the effect of nitric oxide at inhibiting neointimal hyperplasia in a rat model of type 1 diabetes.

Diabetes confers greater restenosis from neointimal hyperplasia following vascular interventions. While localized administration of nitric oxide (NO) is known to inhibit neointimal hyperplasia, the effect of NO in type 1 diabetes is unknown. Thus the aim of this study was to determine the efficacy of NO following arterial injury, with and without exogenous insulin administration. Vascular smooth muscle cells (VSMC) from lean Zucker (LZ) rats were exposed to the NO donor, DETA/NO, following treatment with different glucose and/or insulin concentrations. DETA/NO inhibited VSMC proliferation in a concentration-dependent manner to a greater extent in VSMC exposed to normal-glucose vs. high-glucose environments, and even more effectively in normal-glucose/high-insulin and high-glucose/high-insulin environments. G(0)/G(1) cell cycle arrest and cell death were not responsible for the enhanced efficacy of NO in these environments. Next, type 1 diabetes was induced in LZ rats with streptozotocin. The rat carotid artery injury model was performed. Type 1 diabetic rats experienced no significant reduction in neointimal hyperplasia following arterial injury and treatment with the NO donor PROLI/NO. However, daily administration of insulin to type 1 diabetic rats restored the efficacy of NO at inhibiting neointimal hyperplasia (60% reduction, P < 0.05). In conclusion, these data demonstrate that NO is ineffective at inhibiting neointimal hyperplasia in an uncontrolled rat model of type 1 diabetes; however, insulin administration restores the efficacy of NO at inhibiting neointimal hyperplasia. Thus insulin may play a role in regulating the downstream beneficial effects of NO in the vasculature.

Modified prosthetic vascular conduits.

Atherosclerosis in the form of peripheral arterial disease results in significant morbidity. Surgical treatment options for peripheral arterial disease include angioplasty, endarterectomy, and bypass grafting. For bypass grafting, vein remains the conduit of choice; however, poor quality and limited availability have led to the use of prosthetic materials. Unfortunately, because of a lack of endothelium and compliance mismatch, neointimal hyperplasia develops aggressively, resulting in high failure rates. To improve graft patency, investigators have developed surgical, chemical, and biological graft modifications. This review describes common prosthetic materials, as well as approaches currently in use and under investigation to modify and improve prosthetic conduits for bypass grafting in an effort to improve graft patency rates.

HIV and anal cancer outcomes: a single institution's experience.

PURPOSE: The purpose of this study is to identify the effect of HIV status on outcome of treatment for squamous-cell carcinoma of the anal canal. METHODS: A retrospective review was performed on all patients with squamous-cell carcinoma of the anal canal treated at a single academic institution between January 1996 and December 2006. RESULTS: Our search identified 87 (21 HIV-positive) patients who had invasive squamous-cell cancer. The median follow-up was 38 months. Eighty-five percent of HIV-negative patients and 81 percent of HIV-positive were identified as complete responders at 6 weeks after completion of combined modality therapy. Eight percent of HIV-negative and 29 percent of HIV-positive patients developed recurrent disease after 6 months (P = 0.0009). Overall survival for HIV-negative and HIV-positive patients was 71 percent and 73 percent, respectively. CONCLUSIONS: HIV-positive patients respond equally to combined modality therapy but have recurrences more frequently than patients who are HIV negative. Overall survival in these two groups is equivalent.

Abdominal cocoon: an unexpected cause of ascites in a healthy patient.

Abdominal cocoon is the idiopathic fibrotic encasement of abdominal organs. It classically presents as small bowel obstruction in young women. In this case report, we present a rare example of a patient presenting solely with massive ascites of presumed gynecologic origin, who upon surgical exploration was found to have abdominal cocoon. We discuss the patient's unique disease presentation, unrevealing work-up and the treatment strategy pursued, and provide a review of the literature.

Posttraumatic hernias: historical overview and review of the literature.

Diaphragmatic, lumbar, and extra-thoracic hernias are well-described complications of blunt trauma. However, in the absence of an immediate indication for surgery in the injured patient, early recognition of these hernias can be a diagnostic challenge and delayed presentation is common. Upon diagnosis, surgical repair is necessary secondary to the high morbidity and mortality associated with herniation and strangulation of abdominal organs. Surgical treatment of these hernias is evolving and a variety of options are available to the surgeon. This article will provide a historical overview of post-traumatic diaphragmatic and multi-cavity hernias, and a review of the literature addressing key issues of diagnosis and management.

Effect of nitric oxide on neointimal hyperplasia based on sex and hormone status.

Nitric oxide (NO)-based therapies decrease neointimal hyperplasia; however, studies have been performed only in male animal models. Thus, we sought to evaluate the effect of NO on vascular smooth muscle cells (VSMC) in vitro and neointimal hyperplasia in vivo based on sex and hormone status. In hormone-replete medium, male VSMC proliferated at greater rates than female VSMC. In hormone-depleted medium, female VSMC proliferated at greater rates than male VSMC. However, in both hormone environments, NO inhibited proliferation and migration to a greater extent in male compared to female VSMC. These findings correlated with greater G0/G1 cell cycle arrest and changes in cell cycle protein expression in male compared to female VSMC after exposure to NO. Next, the rat carotid artery injury model was used to assess the effect of NO on neointimal hyperplasia in vivo. Consistent with the in vitro data, NO was significantly more effective at inhibiting neointimal hyperplasia in hormonally intact males compared to females using weight-based dosing. An increased weight-based dose of NO in females was able to achieve efficacy equal to that in males. Surprisingly, NO was less effective at inhibiting neointimal hyperplasia in castrated animals of both sexes. In conclusion, these data suggest that NO inhibits neointimal hyperplasia more effectively in males compared to females and in hormonally intact compared to castrated rats, indicating that the effects of NO in the vasculature may be sex- and hormone-dependent.

Biodegradable nitric oxide-releasing poly(diol citrate) elastomers.

We have developed novel poly(diol citrate) elastomers, which are capable of providing localized and sustained release of nitric oxide (NO). The elastomer prepolymer was obtained by condensation of citric acid, 1,8-octanediol, and N,N'-bis(2-hydroxyethyl)ethylenediamine at 130 degrees C for 40 min. Films were prepared by solvent casting followed by crosslinking at 80 degrees C for 4 days. Mechanical properties were tested. NO-releasing expanded poly(tetrafluoroethylene) (ePTFE) vascular grafts were fabricated by coating the graft's lumen with the prepolymer and crosslinking it at 80 degrees C for 4 days prior to diazeniumdiolation. Samples were diazeniumdiolated via exposure to pressurized NO. Cell compatibility was assessed by monitoring the proliferation of porcine aortic smooth muscle cells (PASMC) on the elastomers. Degradation in phosphate buffer saline (PBS) (pH = 7) at 37 degrees C was evaluated for up to 6 weeks. The secondary amine-containing poly(diol citrate) films had a Young's modulus that ranged from 5.91 to 32.64 MPa, an ultimate tensile stress that ranged from 1.47 to 10.71 MPa, and an elongation at break from 200 to 260%, depending on the content of secondary amine in the feed monomer. These elastomers were degradable and compatible with PASMC. Furthermore, degradation rate was found to be independent of the content of secondary amines in the prepolymer. The NO release from diazeniumdiolated films and ePTFE grafts was sustained for two days. In conclusion, these novel diazeniumdiolated polyester elastomers may be useful in medical devices that require blood contact or control of cell proliferation.

Citric acid-based elastomers provide a biocompatible interface for vascular grafts.

Prosthetic vascular bypass grafting is associated with poor long-term patency rates. Herein, we report on the mid-term performance of expanded polytetrafluoroethylene (ePTFE) vascular grafts modified with a citric acid-based biodegradable elastomer. Through a spin-shearing method, ePTFE grafts were modified by mechanically coating a layer of poly(1,8 octanediol citrate) (POC) onto the luminal nodes and fibrils of the ePTFE. Control and POC-ePTFE grafts were implanted into the porcine carotid artery circulation as end-to-side bypass grafts. Grafts were assessed by duplex ultrasonography, magnetic resonance angiography, and digital subtraction contrast angiography and were all found to be patent with no hemodynamically significant stenoses. At 4 weeks, POC-ePTFE grafts were found to be biocompatible and resulted in a similar extent of neointimal hyperplasia as well as leukocyte and monocyte/macrophage infiltration as control ePTFE grafts. Furthermore, POC supported endothelial cell growth. Lastly, scanning electron microscopy confirmed the presence of POC on the ePTFE grafts at 4 weeks. Thus, these data reveal that surface modification of blood-contacting surfaces with POC results in a biocompatible surface that does not induce any untoward effects or inflammation in the vasculature. These findings are important as they will serve as the foundation for the development of a drug-eluting vascular graft.

Medical oncology: Multimodality therapy in unresectable colorectal cancer.

Mathis et al. aimed to determine the effect of multimodality therapy on recurrence and survival in patients with locally advanced colorectal cancer. Use of multimodality treatment led to excellent local control with five year disease-free and overall survival rates comparable to that of stage-matched resectable colorectal cancers.

Nitric oxide and nanotechnology: a novel approach to inhibit neointimal hyperplasia.

OBJECTIVE: Nitric oxide (NO) has been shown to inhibit neointimal hyperplasia after arterial interventions in several animal models. To date, however, NO-based therapies have not been used in the clinical arena. Our objective was to combine nanofiber delivery vehicles with NO chemistry to create a novel, more potent NO-releasing therapy that can be used clinically. Thus, the aim of this study was to evaluate the perivascular application of spontaneously self-assembling NO-releasing nanofiber gels. Our hypothesis was that this application would prevent neointimal hyperplasia. METHODS: Gels consisted of a peptide amphiphile, heparin, and a diazeniumdiolate NO donor (1-[N-(3-Aminopropyl)-N-(3-ammoniopropyl)]diazen-1-ium-1,2-diolate [DPTA/NO] or disodium 1-[(2-Carboxylato)pyrrolidin-1-yl]diazen-1-ium-1,2-diolate [PROLI/NO]). Nitric oxide release from the gels was evaluated by the Griess reaction, and scanning electron microscopy confirmed nanofiber formation. Vascular smooth muscle cell (VSMC) proliferation and cell death were assessed in vitro by (3)H-thymidine incorporation and Personal Cell Analysis (PCA) system (Guava Technologies, Hayward, Calif). For the in vivo work, gels were modified by reducing the free-water content. Neointimal hyperplasia after periadventitial gel application was evaluated using the rat carotid artery injury model at 14 days (n = 6 per group). Inflammation and proliferation were examined in vivo with immunofluorescent staining against CD45, ED1, and Ki67 at 3 days (n = 2 per group), and graded by blinded observers. Endothelialization was assessed by Evans blue injection at 7 days (n = 3 per group). RESULTS: Both DPTA/NO and PROLI/NO, combined with the peptide amphiphile and heparin, formed nanofiber gels and released NO for 4 days. In vitro, DPTA/NO inhibited VSMC proliferation and induced cell death to a greater extent than PROLI/NO. However, the DPTA/NO nanofiber gel only reduced neointimal hyperplasia by 45% (intima/media [I/M] area ratio, 0.45 +/- 0.07), whereas the PROLI/NO nanofiber gel reduced neointimal hyperplasia by 77% (I/M area ratio, 0.19 +/- 0.03, P < .05) vs control (injury alone I/M area ratio, 0.83 +/- 0.07; P < .05). Both DPTA/NO and PROLI/NO nanofiber gels significantly inhibited proliferation in vivo (1.06 +/- 0.30 and 0.19 +/- 0.11 vs injury alone, 2.02 +/- 0.20, P < .05), yet had minimal effect on apoptosis. Only the PROLI/NO nanofiber gel inhibited inflammation (monocytes and leukocytes). Both NO-releasing nanofiber gels stimulated re-endothelialization. CONCLUSIONS: Perivascular application of NO-releasing self-assembling nanofiber gels is an effective and simple therapy to prevent neointimal hyperplasia after arterial injury. Our study demonstrates that the PROLI/NO nanofiber gel most effectively prevented neointimal hyperplasia and resulted in less inflammation than the DPTA/NO nanofiber gel. This therapy has great clinical potential to prevent neointimal hyperplasia after open vascular interventions in patients.

Nitric oxide: what a vascular surgeon needs to know.

Atherosclerosis in the form of peripheral arterial disease results in significant morbidity and mortality. Surgical treatment options for peripheral arterial disease include angioplasty with and without stenting, endarterectomy, and bypass grafting. Unfortunately, all of these procedures injure the vascular endothelium, which impairs its ability to produce nitric oxide (NO) and ultimately leads to neointimal hyperplasia and restenosis. To improve on current patency rates after vascular procedures, investigators are engaged in research to improve the bioavailability of NO at the site of vascular injury in an attempt to reduce the risk of thrombosis and restenosis after successful revascularization. This article reviews some of the previous research that has aimed to improve NO bioavailability after vascular procedures whether through systemic or local delivery, as well as to describe some of the NO-releasing products that are currently undergoing study for use in clinical practice.