Methylene blue dye-induced skin necrosis in immediate breast reconstruction: evaluation and management

A comparison of the postoperative outcomes between intraoperative leak testing and no intraoperative leak testing for gastric cancer surgery: a systematic review and meta-analysis

BACKGROUND

Postoperative anastomotic leakage (PAL) is a serious complication of gastric cancer surgery. Although perioperative management has made considerable progress, anastomotic leakage (AL) cannot always be avoided. The purpose of this study is to evaluate whether intraoperative leak testing (IOLT) can reduce the incidence of PAL and other postoperative outcomes in gastric cancer surgery.

MATERIALS AND METHODS

In this meta-analysis, we searched the PubMed, Embase, and Cochrane Library databases for clinical trials to assess the application of IOLT in gastric cancer surgery. All patients underwent laparoscopic radical gastrectomy for gastric cancer surgery. Studies comparing the postoperative outcomes of IOLT and no intraoperative leak testing (NIOLT) were included. Quality assessment, heterogeneity, risk of bias, and the level of evidence of the included studies were evaluated. PAL, anastomotic-related complications, 30-day mortality, and reoperation rates were compared between the IOLT and NIOLT group.

RESULTS

Our literature search returned 721 results, from which six trials (a total of 1,666 patients) were included in our meta-analysis. Statistical heterogeneity was low. The primary outcome was PAL. IOLT reduced the incidence of PAL [2.09% vs 6.68%; (RR = 0.31, 95% Cl 0.19-0.53, P < 0.0001]. Anastomotic-related complications, which included bleeding, leakage, and stricture, were significantly higher in the NIOLT group than in the IOLT group [3.24% VS 10.85%; RR = 0.30, 95% Cl 0.18-0.53, P < 0.0001]. Moreover, IOLT was associated with lower reoperation rates [0.94% vs 6.83%; RR = 0.18, 95% CI 0.07-0.43, P = 0.0002].

CONCLUSION

Considering the observed lower incidence of postoperative anastomotic leakage (PAL), anastomotic-related complications, and reoperation rates, IOLT appears to be a promising option for gastric cancer surgery. It warrants further study before potential inclusion in future clinical guidelines.

Determining Accurate Dye Combinations for Sentinel Lymph Node Detection: A Systematic Review

Background

Lymphatic dyes are commonly used to map the drainage path from tumor to lymphatics, which are biopsied to determine if spread has occurred. A blue dye in combination with technetium-99 is considered the gold standard for mapping, although many other dyes and dye combinations are used. Not all of these substances have the same detection efficacy.

Methods

A systematic review of PubMed, SCOPUS, Web of Science, and Medline was performed. The predefined search terms were (indocyanine green OR isosulfan blue OR lymphazurin OR patent blue OR methylene blue OR fluorescein OR technetium-99) AND combination AND dye AND (sentinel lymph node biopsy OR lymphedema OR lymphatics OR lymph OR microsurgery OR cancer OR tumor OR melanoma OR carcinoma OR sarcoma).

Results

The initial search returned 4267 articles. From these studies, 37 were selected as candidates that met inclusion criteria. After a full-text review, 34 studies were selected for inclusion. Eighty-nine methods of sentinel lymph node (SLN) detection were trialed using 22 unique dyes, dye combinations, or other tracers. In total, 12,157 SLNs of 12,801 SLNs were identified. Dye accuracy ranged from 100% to 69.8% detection. Five dye combinations had 100% accuracy. Dye combinations were more accurate than single dyes.

Conclusions

Combining lymphatic dyes improves SLN detection results. Replacing technetium-99 with ICG may allow for increased access to SLN procedures with comparable results. The ideal SLN tracer is a low-cost molecule with a high affinity for lymphatic vessels due to size and chemical composition, visualization without specialized equipment, and no adverse effects.

Methylene blue dose-dependently induces cutaneous inflammation and heat hyperalgesia in a novel rat model

Methylene blue (MB) has been shown to reduce mortality and morbidity in vasoplegic patients after cardiac surgery. Though MB is considered to be safe, extravasation of MB leading to cutaneous toxicity has been reported. In this study, we sought to characterize MB-induced cutaneous toxicity and investigate the underlying mechanisms. To induce MB-induced cutaneous toxicity, we injected 64 adult male Sprague-Dawley rates with 200 µL saline (vehicle) or 1%, 0.1%, or 0.01% MB in the plantar hind paws. Paw swelling, skin histologic changes, and heat and mechanical hyperalgesia were measured. Injection of 1%, but not 0.1% or 0.01% MB, produced significant paw swelling compared to saline. Injection of 1% MB produced heat hyperalgesia but not mechanical hyperalgesia. Pain behaviors were unchanged following injections of 0.1% or 0.01% MB. Global transcriptomic analysis by RNAseq identified 117 differentially expressed genes (111 upregulated, 6 downregulated). Ingenuity Pathway Analysis showed an increased quantity of leukocytes, increased lipids, and decreased apoptosis of myeloid cells and phagocytes with activation of IL-1β and Fos as the two major regulatory hubs. qPCR showed a 16-fold increase in IL-6 mRNA. Thus, using a novel rat model of MB-induced cutaneous toxicity, we show that infiltration of 1% MB into cutaneous tissue causes a dose-dependent pro-inflammatory response, highlighting potential roles of IL-6, IL-1β, and Fos. Thus, anesthesiologists should administer dilute MB intravenously through peripheral venous catheters. Higher concentrations of MB (1%) should be administered through a central venous catheter to minimize the risk of cutaneous toxicity.

Blue Wheals and Blue Angioedema Induced by Blue Dyes: A Systematic Review

BACKGROUND

Blue wheals and blue angioedema, the adverse reactions to blue dye injections with or without anaphylaxis, are poorly defined.

OBJECTIVE

The objective is to review the characteristics (ie, sex and age at onset, interval between blue dye injection and symptom onset, clinical manifestations, duration of blue wheals or angioedema), natural courses, and treatments of blue dye adverse reactions.

METHODS

A review of the articles published through July 2021 was performed per the Preferred Reporting Items for Systematic Reviews and Meta-Analysis recommendations.

RESULTS

Across 523 patients (175 studies) with any adverse reactions to blue dye injections, wheals, angioedema, or both occurred in 193 patients (36.9%). Of these 193 patients, 68 patients (35.2%) developed blue wheals or angioedema, 118 (61.1%) had ordinary wheals or angioedema (nonbluish), and 7 had both (3.6%). We reviewed 169 patients with available data (99 with ordinary lesions and 70 with blue lesions). Patent blue violet had the highest rate of inducing blue wheals or angioedema (odds ratio 4.9). Almost half of the patients with blue wheals or angioedema developed systemic symptoms; and of those with systemic symptoms, all except 1 progressed to anaphylaxis. On-demand treatments with antihistamines, corticosteroids, and epinephrine were commonly used and effective.

CONCLUSIONS

Using blue dyes can lead to blue wheals or angioedema and systemic reactions. In patients with a history of a severe allergic reaction to a blue dye, repeat administration of a blue dye should be used only after carefully weighing all the risks and benefits.

Efficacy and safety of anastomotic leak testing in gastric cancer: a randomized controlled trial

BACKGROUND

Anastomosis-related complications such as bleeding, leakage, and strictures, continue to be serious complications of gastric cancer surgery. Presently, these complications have yet to be reliably prevented. Here we design a comprehensive leak testing procedure which combines gastroscopy, air, and methylene blue (GAM) leak testing. We aimed to evaluated the efficacy and safety of the GAM procedure in patients with gastric cancer.

METHODS

Patients aged 18-85 years without an unresectable factor as confirmed via CT were enrolled in a prospective randomized clinical trial at a tertiary referral teaching hospital and were randomly assigned to two groups: intraoperative leak testing group (IOLT) and no intraoperative leak testing group (NIOLT). The primary endpoint was the incidence of postoperative anastomosis-related complications in the two groups.

RESULTS

148 patients were initially randomly assigned to the IOLT group (n = 74) and to the NIOLT group (n = 74) between September 2018 and September 2022. After exclusions, 70 remained in the IOLT group and 68 in the NIOLT group. In the IOLT group, 5 patients (7.1%) were found to have anastomotic defects intraoperatively, which included anastomotic discontinuity, bleeding, and strictures. The NIOLT group had a higher incidence of postoperative anastomotic leakage compared to the IOLT group: 4 patients (5.8%) vs 0 patients (0%), respectively. No GAM-related complications were observed.

CONCLUSION

The GAM procedure is an intraoperative leak test that can be performed safely and efficiently after a laparoscopic total gastrectomy. GAM anastomotic leak testing may effectively prevent technical defect-related anastomotic complications in patients with gastric cancer who undergo a gastrectomy.

TRIAL REGISTRATION

Clinical Trials.gov Identifier: NCT04292496.

A Novel Intraoperative Leak Test Procedure (GAM Procedure) to Prevent Postoperative Anastomotic Leakage in Gastric Cancer Patients Who Underwent Gastrectomy

BACKGROUND

Anastomotic leakage following a radical gastrectomy is a serious complication of gastric cancer and esophagogastric junction cancer. The benefit of intraoperative leak testing for the prevention of postoperative anastomotic leakage has been controversial. We introduce a new procedure, which combines the techniques of gastroscopy, air, and methylene blue (GAM) for intraoperative leakage testing. Our objective was to evaluate the efficacy and safety of the GAM procedure for intraoperative leak testing and to compare the surgical complications of gastric cancer patients who underwent gastrectomy with and without intraoperative leak testing using the GAM procedure.

MATERIALS AND METHODS

A total of 210 patients who underwent radical gastrectomy for gastric cancer were included. Patients were divided into 2 groups: the intraoperative leak testing group using the GAM procedure (IOLT), and the group for which no intraoperative leak testing was done (NIOLT). Clinical and pathologic characteristics, the incidence of postoperative anastomotic leakage, and other surgical complications were compared between the 2 groups.

RESULTS

There were 82 patients in the IOLT group and 82 patients in the NIOLT group after propensity score matching. In the IOLT group, 4 (4.9%) patients were found to have anastomotic discontinuity during the operation; we repaired these anastomotic discontinuities intraoperatively. The incidence of postoperative anastomotic leakage was higher in the NIOLT group compared with the IOLT group, 6 (7.3%) versus 0 (0%), respectively ( P =0.01). The average time of the GAM procedure was 4.99±1.75 minutes. The surgical time was prolonged by 30 minutes in the IOLT group compared with the NIOLT group, 302.2±79.9 versus 272.1±85.2, respectively ( P =0.02). The length of hospital stay, 15.80±4.55 versus 17.00±6.20 ( P =0.16) was reduced in the IOLT group compared with the NIOLT group. The logistic regression model suggested that IOLT, sex, age, Eastern Cooperative Oncology Group, cT stage, tumor diameter, pT stage, pN stage, and Lauren classification were not risk factors for postoperative complication.

CONCLUSIONS

The GAM procedure of intraoperative leakage testing can effectively reduce the incidence of postoperative anastomotic leakage in gastric cancer patients undergoing gastrectomy.

Contrast-enhanced ultrasound-guided sentinel lymph node biopsy in early-stage breast cancer: a prospective cohort study

OBJECTIVE

This study evaluated the identification efficiency of contrast-enhanced ultrasound (CEUS) for sentinel lymph nodes (SLN) to accurately represent the axillary node status in early-stage breast cancer.

METHOD

In total, 109 consecutive consenting patients with clinically node-negative and T1-2 breast cancer were included in this study. All patients received CEUS to identify SLN before surgery, and a guidewire was deployed to locate SLN in those who were successfully explored by CEUS. The patients underwent sentinel lymph node biopsy (SLNB), and the blue dye was used to trace SLN during the surgery. The decision to perform axillary lymph node dissection (ALND) depended on the intraoperative pathological identification of SLN by CEUS (CE-SLN). The concordance rate of pathological status between CE-SLN and dyed SLN was calculated.

RESULT

The CEUS detection rate was 96.3%; CE-SLN failed in 4 patients. Among the remaining 105 successful identifications, 18 were CE-SLN positive by intraoperative frozen section, and one with CE-SLN micrometastasis was diagnosed by paraffin section. No additional lymph node metastases were found in CE-SLN-negative patients. The concordance rate of pathological status between CE-SLN and dyed SLN was 100%.

CONCLUSION

CEUS can accurately represent the status of axillary lymph nodes in patients with clinically node-negative and small tumor burden breast cancer.

Is Using Closed Incision Negative Pressure Therapy in Reconstructive and Oncoplastic Breast Surgery Helpful in Reducing Skin Necrosis?

Introduction Skin necrosis is a major concern of morbidity in patients undergoing reconstructive and oncoplastic breast surgery (ROBS) as it may lead to a poor aesthetic outcome, necessitate further surgery, and delay adjuvant chemotherapy and radiotherapy if required postoperatively. Some studies have reported that closed incision negative pressure therapy (ciNPT) immediately after surgery can reduce the incidence of wound complications. Our study aimed to investigate the effect of ciNPT on skin necrosis rate after ROBS. Methods Our study included 82 patients in a single center who underwent 121 ROBS procedures. We used conventional dressing in 42 patients (62 procedures, group A), while we used ciNPT in 40 patients (59 procedures, group B). When ciNPT dressing was introduced in our breast unit, 40 patients with 59 ROBS procedures who had ciNPT dressing were studied prospectively. The risk factors recorded were age, body mass index (BMI), history of previous radiotherapy, history of smoking, type of incision, type of operation, breast tissue specimen weight, use of neoadjuvant chemotherapy, and implant size. Skin necrosis was classified as "minor" if it was managed conservatively with regular dressings and "major" if surgical debridement in theater and/or exchange or implant removal was necessary. Results The incidence of overall skin necrosis in the conventional dressing group was 17.7% (11/62), while in the ciNPT group, it was higher at 25.4% (15/59), although this was not statistically significant (p = 0.51). ciNPT also did not show a statistically significant difference from the conventional dressing in the rate of minor necrosis (18.6% versus 11.2%, respectively; p = 0.44) and major necrosis (6.7% versus 6.4%, respectively; p = 1.00) Conclusion Our data has shown no superiority of ciNPT in reducing skin necrosis rate in a patient undergoing reconstructive and oncoplastic breast surgery, contrary to many other published reports. However, it may have reduced rates of other wound complications such as wound dehiscence, wound infection, and hypertrophic scar formation, which were not studied in our cohort. Further studies are needed to confirm its benefits, especially in high-risk patients.

Compartment syndrome secondary to intra-operative IV methylene blue extravasation to detect ureteral injury

Compartment syndrome of the extremities is a rare but potentially devastating condition. We herein report a case of a 53-year old female with an unusual case of hand compartment syndrome and fasciitis secondary to methylene blue (MB) extravasation to detect urinary tract injury intraoperatively. This was recognized immediately and fasciotomy was performed. Features of this case are discussed together with its implications. Despite MB's long history of use, few adverse events of an accidental extravasation have been reported.

Methylene blue: a controversial diagnostic acid and medication?

A narrative review of the literature was conducted to determine if the administration of methylene blue (MB) in humans has potential risks. Studies were identified from MEDLINE, Web of Science, Scopus, and Cochrane. MB is a diagnostic substance used during some diagnostic procedures and also a part of the treatment of several diseases including methemoglobinemia, vasoplegic syndrome, fosfamide-induced encephalopathy, and cyanide intoxication, and the detection of leaks or position of parathyroid corpuscles during surgery. Although the use of MB is historically justified, and it ought to be safe, because it originated as a diagnostic material, the basic toxicological characteristics of this substance are unknown. Despite reports of severe adverse effects of MB, which could significantly exceed any possible benefits evaluated for the given indication. Therefore, the clinical use of MB currently represents a controversial problem given the heterogeneity of available data and the lack of preclinical data. This is in conflict with standards of safe use of such substances in human medicinal practice. The toxic effects of the application of MB are dose-dependent and include serious symptoms such as hemolysis, methemoglobinemia, nausea and vomitus, chest pain, dyspnoea, and hypertension. Some countries regard MB as harmful because of the resulting skin irritation and triggering of an adverse inflammatory response. MB induced serotoninergic toxicity clinically manifests as neuromuscular hyperactivity. This review aims to summarize the current understanding concerning the indications for MB administration and define the potential adverse effects of MB.

The Effects of Methylene Blue and Carbon Nanoparticles on Transplanted Lymph Node Survival, Reconstructed Lymphatic Function, and Changes in Inflammatory and Fibrosis Factors

BACKGROUND AND OBJECTIVES

Methylene blue (MB) and carbon nanoparticles (CNs) can be used as a simple method for reverse lymphatic mapping. We investigated whether the two tracers had an impact on the survival of lymph nodes and the function of reconstructed lymph vessels after transplantation, as well as the changes in surrounding related factors.

METHODS

The stained lymph nodes were non-vascularized transplanted into the contralateral popliteal fossa in mice. After 4 weeks, the lymphatic recanalization was detected. The samples were harvested for pathological detection and PCR. In addition, the transport ability of the recanalized lymphatics to tumor cells was also explored.

RESULTS

Compared with the control group, there was no significant difference of the MB and CNs groups in the drainage function of recanalized lymphatic vessels, the survival of lymph nodes, or the transport capacity to tumor cells. TNF-α and IL-6 were significantly higher in the two tracer groups (**p < 0.01). Besides, the α-SMA was significantly increased in the CNs group (*p < 0.05).

CONCLUSIONS

Two tracers have no effect on the survival of transplanted lymph nodes, nor do they affect the drainage ability or tumor cell capture ability of the reconstructed lymphatics, despite improving TNF-α and IL-6 levels and the deposition of CNs.

Validation sentinel lymph node biopsy study in cN0 axilla using low-cost dual dye technique: potential solution for resource poor settings

BACKGROUND

Sentinel lymph node biopsy (SLNB) using radio-pharmaceutical and a blue dye is gold standard for axillary staging in clinically node-negative breast cancer. High costs and limited availability of radio-pharmaceutical and/or gamma probe are major deterrents in performing SLNB in developing countries. In this study, we evaluated feasibility of SLN identification (SLN-IR) of fluorescein-guided (FG) SLNB in combination with methylene blue dye (MBD).

METHODS

This was a prospective cross-sectional non-randomized validation study in patients with clinically node-negative axilla. Patients underwent validation SLNB using fluorescein (and blue LED light) and MBD. Axillary dissection was performed irrespective of SLNB histology. SLIN-IR and False Negative Rate (FNR) were assessed for both groups.

RESULTS

The SLNs were identified in 29 (96.6%) pre-chemotherapy patients and 23 (82%) post Neoadjuvant Chemotherapy (NACT) patients. The median number of sentinel lymph nodes identified was 3 (range of 1-5) in pre-chemotherapy patients and 1 (range of 1-3) in post NACT patients. The SLN-IR using MBD was 90%, FD was 86.7% and combined MBD FD was 96.7% in pre-chemotherapy patients. The SLN-IR using MBD was 82%, FD was 71% and combined MBD FD was 82% in in post NACT patients. The false negative rate (FNR) in pre-chemotherapy group was 8.0% (MBD), 8.3% (FD) and 7.4% (MBD + FD). The FNR in post NACT group was 8.7% (MBD), 10% (FD) and 8.7% (MBD + FD).

CONCLUSION

This prospective validation study showed adequate SLN-IR and FNR using low-cost dual dyes in early breast cancer patients and can be used in low resource settings. However, SLNB in post NACT axilla though viable along with a satisfactory FNR, is associated with low identification rate and needs further evaluation.

Recommendations for Management of Noncytotoxic Vesicant Extravasations

To prepare clinicians to treat extravasation of noncytotoxic vesicants with antidotes and thermal compresses, a literature review was performed to identify noncytotoxic vesicants and to create evidence and consensus-based recommendations. The stage of injury and vesicant's mechanism of tissue injury dictate treatment. For a vasopressor extravasation, warm compresses and administration of a vasodilator are recommended. For osmolarity, pH, absorption refractory, and cytotoxic concentration-dependent vesicants, warm compresses and administration of hyaluronidase are recommended. Compared with potentially catastrophic costs of undertreatment, the cost of overtreatment is minimal.

Does methylene blue increases capsular contracture in immediate breast reconstruction with silicone implant? An experimental study

Recently, most of the immediate breast reconstructions following mastectomy are being carried out with the use of silicone implants. In these patients, methylene blue is being used for the detection of sentinel lymph nodes. This experimental study was performed to determine the effect of methylene blue on capsular contracture around breast implants. Thirty-two Sprague Dawley rats were divided into 4 groups. Custom made silicone blocks were placed on the back of animals. In group 1, the incision was closed without performing any additional procedure. In group 2 (control), 0.1 mL of 0.9% normal saline was instilled into the pocket. Group 3 and 4 (study groups) received 0.1 and 0.2 mL of 1% methylene blue, respectively. On postoperative day 60, implants and capsular tissue were extracted. Capsule formation was evaluated both macroscopically and microscopically. The histological evaluation included capsule thickness, inflammation, neovascularization, and fibrosis gradients. Regarding capsule thickness, there were statistically significant differences between groups 1-3, 1-4, 2-3, and 2-4. Although there were more moderate and severe inflammation gradients in groups III and IV, there was no significant difference regarding inflammation severity between control and study groups. In respect of vascular proliferation, there was a statistically significant difference between control and study groups. Similarly, fibrosis gradients were higher in both groups 3 and 4. The study showed that the injection of methylene blue around silicone implants enhanced the formation of capsular contracture. In this case, the degree of contracture was independent of the dose given. Abbreviations: CC: capsular contracture; MM: methylene blue; SLNB: sentinel lymph node biopsy; NS: normal saline; H&E: hematoxylin and eosin; D: dorsal; V: ventral; L: lateral; n: frequency.

Evaluating the safety of oral methylene blue during swallowing assessment: a systematic review

OBJECTIVE

Methylene blue (MB) is frequently administered during fiberoptic endoscopic evaluation of swallowing (FEES) to enhance visualization of pharyngeal bolus transit. However, the safety of MB is being questioned since serious adverse events (AEs) such as hemodynamic instability, hemolysis, and serotonin syndrome were reported. The aim of this study is a systematic analysis of the literature to obtain an evidence-based overview of AEs due to oral administration of MB and to determine its safety as a food dye during swallowing assessment.

METHODS

A systematic literature search was carried out in PubMed, Embase, and Cochrane Library. Two reviewers independently selected articles describing oral administration of MB as a main diagnostic/therapeutic intervention, dosage, and AEs. Expert opinions, conference papers, sample size < 10, and animal studies were excluded. Level of evidence of the included studies was determined.

RESULTS

A total of 2264 unduplicated articles were obtained. Seventeen studies met the inclusion criteria with 100% agreement between the two reviewers. Among these, twelve studies were randomized controlled trials. In a pooled population of 1902 patients receiving oral MB, three serious AEs were reported related to MB. Non-serious AEs showed a dose-related trend and were usually mild and self-limiting. A meta-analysis could not be performed as studies were methodologically too heterogeneous.

CONCLUSION

Serious AEs due to oral administration of MB are rare (n = 3, 0.16%). MB-related non-serious AEs are mild, self-limiting, and show a dose-related trend. These findings indicate that it is safe to use small amounts of MB as a food dye during swallowing examinations.

The relationship between post-surgery infection and breast cancer recurrence

Breast cancer is the second most prevalent form of cancer in women worldwide, with surgery remaining the standard treatment. The adverse impact of the surgery remains controversial. It has been suggested that systemic factors during the postoperative period may increase the risk of recurrence, specifically surgical site infection (SSI). The aim of this review was to critically appraise current published literature regarding the influence of SSIs, after primary breast cancer surgery, on breast cancer recurrence, and to delve into potential links between these. This systematic review adopted two approaches: to identify the incidence rates and risk factors related to SSI after primary breast cancer surgery; and, secondly, to examine breast cancer recurrence following SSI occurrence. Ninety-nine studies with 484,605 patients were eligible in the SSI-focused searches, and 53 studies with 17,569 patients for recurrence-focused. There was a 13.07% mean incidence of SSI. Six-hundred and thirty-eight Gram-positive and 442 Gram-negative isolates were identified, with methicillin-susceptible Staphylococcus aureus and Escherichia coli most commonly identified. There were 2077 cases of recurrence (11.8%), with 563 cases of local recurrence, 1186 cases of distant and 25 cases which recurred both locally and distantly. Five studies investigated the association between SSI and breast cancer recurrence with three concluding that an association did exist. In conclusion, there is association between SSI and adverse cancer outcomes, but the cellular link between them remains elusive. Confounding factors of retrospective study design, surgery type and SSI definition make results challenging to compare and interpret. A standardized prospective study with appropriate statistical power is justified.

Cutaneous adverse effects of methylene blue in an animal skin-flap model

Background and objectives: Sentinel lymph node biopsy is important for metastasis surveillance in the management of a number of human cancers. Identification of sentinel lymph nodes may be facilitated by the use of several methods including methylene blue injection. However tissue necrosis is a known effect of methylene blue application. This study aimed to investigate the effects of methylene blue injection on skin flaps using a rodent model.Methods: Modified McFarlane flaps were prepared using Wistar Albino rats. Local injection of methylene blue was given to one group while saline was injected into the control group. A third group received systemic methylene blue via intraperitoneal injection. Observational and histological comparison was made between the groups to investigate the necrotic effects of methylene blue on skip flaps.Results: The control group's surviving flap areas were significantly larger than local methylene blue group's surviving flap area. However, there was no significant difference in skin flap survival area between the control group and the systemic methylene blue group. Furthermore, there is no significant difference between local and systemic methylene blue group's surviving flap areas.Conclusions: Local methylene blue injection increases skin necrosis and decreases rates of surviving flap areas in an experimental rat models.

Minimally invasive salvage of infected breast tissue expanders: A continuous closed irrigation technique based on surface biofilm disruption

BACKGROUND

Removal of the infected device has been the general treatment for device-associated infection in antibiotic failure. There have been anecdotal attempts to salvage infected medical devices by introducing a continuous closed irrigation system.

OBJECTIVE

This study examines whether continuous closed irrigation of an infected device is a successful alternative to removal in patients with recalcitrant device-associated infection.

METHODS

Patients who were diagnosed with recalcitrant periexpander infections during the course of expander-implant breast reconstruction from 2010 to 2018 were enrolled in a retrospective case-control study. Patients who failed antibiotics before 2017 underwent expander removal, but patients since 2017 underwent continuous closed irrigation of the infected expanders. Treatment details and clinical outcomes were compared. Rationale for expander irrigation was based on review of the current literature on biofilm research.

RESULTS

During the study period, 21 out of the 1176 patients were diagnosed with periexpander infection recalcitrant to antibiotic therapy. Among the 21 patients, 16 underwent expander removal and five underwent expander irrigation. Clinical outcomes were comparable in terms of resolution of infection signs. The irrigation group showed fewer patients who abandoned reconstruction after infection treatment (removal = 11/16, irrigation = 1/5). Literature review revealed that expander irrigation might have induced hydrodynamic disruption of the biofilm structure.

CONCLUSION

Expander irrigation was less invasive than removal and effective in suppressing severe recalcitrant periexpander infection. Continuous closed irrigation of infected expander devices may be a successful antibiofilm strategy in treating device-associated infections in select patients.

Sentinel lymph node mapping by near-infrared fluorescence imaging and contrast-enhanced ultrasound in healthy dogs

Sentinel lymph node (SLN) mapping is a valuable and crucial diagnostic procedure in staging malignancies. We compared two non-invasive techniques, near-infrared (NIR) fluorescence imaging and contrast-enhanced ultrasound (CEUS), to identify the SLNs in three superficial anatomical regions in an animal model. Six healthy laboratory dogs were included in a proof-of-concept trial. A NIR fluorescent dye (Indocyanine Green) and microbubbles (Sonovue) were consecutively injected subdermally in the Inguinal, axillary and popliteal region to map the SLNs. Transcutaneous NIR fluorescence imaging identified SLNs in 17 out of a total of 18 occasions. CEUS identified SLNs in all regions (18/18). Whereas NIR fluorescence imaging performed better in the visualization of the afferent lymphatic tract, CEUS demonstrated different filling patterns of the SLNs, a feature potentially critical for the concept of SLN mapping in cancer patients. Both NIR fluorescence imaging and CEUS are safe, non-invasive, practical and accurate methods to perform real-time transcutaneous SLN mapping with potential in a clinical setting.

Skin Flap Necrosis by Bone Marking with Methylene Blue in Cochlear Implantation

One of surgical complications in cochlear implantation is the necrosis of the skin flap above the receiver-stimulator coil. We present a case of 55-year-old woman who underwent cochlear implantation and developed a bluish skin necrosis due to bone marking. The planned position for the receiver-stimulator was marked using methylene blue through skin to bone. She did not undergo skin flap thinning and underwent successful implantation with complete electrode insertion. Few weeks postoperatively, the patient developed bluish discoloration with progressive thick, blue eschar formation and skin flap necrosis. She subsequently underwent wound debridement and skin flap closure. Cochlear explantation was not necessary. Timely diagnosis and management about this complication is necessary to prevent further skin breakdown and subsequent device extrusion. This report identifies the marking using methylene blue as another possible source of skin flap necrosis in cochlear implantation, and surgeons should be aware of this potential complication.

Feasibility of Charcoal Tattooing for Localization of Metastatic Lymph Nodes in Robotic Selective Neck Dissection for Papillary Thyroid Carcinoma

BACKGROUND

This study aimed to evaluate the feasibility and effectiveness of ultrasound-guided charcoal tattooing in locating metastatic lymph nodes in robotic selective neck dissection (SND) for papillary thyroid carcinoma (PTC).

METHODS

The overall study group comprised 21 patients with PTC who underwent robotic SND via a unilateral transaxillary approach for treatment of suspicious lymph node metastasis in the lateral compartment. Charcoal suspension was injected into 10 of the patients (total of 23 lesions) 1 day before robotic SND. The authors evaluated the location of the tattoos, the success rate of localization, the intraoperative detection rate, and the complications associated with the procedure. The perioperative results were compared with those in the control group of 11 patients who did not receive charcoal tattooing.

RESULTS

Charcoal suspension was successfully injected into 22 of the 23 suspicious lymph nodes (95.7 %). The remaining lesion was located posterior to the internal jugular vein. Therefore, the charcoal was injected into the soft tissue around the lymph node. Ultrasound-guided injections were well tolerated in all the patients, and no major complications occurred. All the charcoal-tattooed lesions were identified intraoperatively by the surgeon. The number of harvested and metastatic lymph nodes in the lateral compartment was greater in the patients with charcoal tattoo localization than in the control group. The two groups did not differ in terms of perioperative complications, operation time, or volume of drainage.

CONCLUSION

Ultrasound-guided charcoal tattooing for localization of metastatic lymph nodes is feasible and effective in robotic SND for the treatment of PTC with lateral compartment lymph node metastasis.

Intraoperative leak testing has no correlation with leak after laparoscopic sleeve gastrectomy

BACKGROUND

Staple line leak is a serious complication of sleeve gastrectomy. Intraoperative methylene blue and air leak tests are routinely used to evaluate for leak; however, the utility of these tests is controversial. We hypothesize that the practice of routine intraoperative leak testing is unnecessary during sleeve gastrectomy.

METHODS

A retrospective cohort study was designed using a prospectively collected database of seven bariatric surgeons from two institutions. All patients who underwent sleeve gastrectomy from March 2012 to November 2014 were included. The performance of intraoperative leak testing and the type of test (air or methylene blue) were based on surgeon preference. Data obtained included BMI, demographics, comorbidity, presence of intraoperative leak test, result of test, and type of test. The primary outcome was leak rate between the leak test (LT) and no leak test (NLT) groups. SAS version 9.4 was used for univariate and multivariate analyses.

RESULTS

A total of 1550 sleeve gastrectomies were included; most were laparoscopic (99.8%), except for one converted and two open cases. Routine intraoperative leak tests were performed in 1329 (85.7%) cases, while 221 (14.3%) did not have LTs. Of the 1329 cases with LTs, there were no positive intraoperative results. Fifteen (1%) patients developed leaks, with no difference in leak rate between the LT and NLT groups (1 vs. 1%, p = 0.999). After adjusting for baseline differences between the groups with a propensity analysis, the observed lack of association between leak and intraoperative leak test remained. In this cohort, leaks presented at a mean of 17.3 days postoperatively (range 1-67 days). Two patients with staple line leaks underwent repeat intraoperative leak testing at leak presentation, and the tests remained negative.

CONCLUSION

Intraoperative leak testing has no correlation with leak due to laparoscopic sleeve gastrectomy and is not predictive of the later development of staple line leak.