Silk Suture Granuloma 37 Years After Scleral Buckle Surgery: A Case Report

PURPOSE

To present a rare presentation of pyogenic granuloma arising almost 4 decades after a scleral buckle for retinal detachment.

METHOD

We describe the clinical presentation, diagnostic workup, and management of a suspicious conjunctival lesion in an immunocompromised patient. We report the histopathological findings and the postoperative outcome.

RESULTS

A 58-year-old man with human immunodeficiency virus presented for evaluation of a possible malignant conjunctival lesion in the left eye. The patient reported that the lesion had appeared 1.5 months before presentation with significant growth over the past month. The patient denied any trauma to the eye other than an ocular history of retinal detachment repair with scleral buckle 37 years earlier. Clinical examination revealed a pink, fleshy, mobile, and lobulated conjunctival lesion measuring 7 mm by 10 mm, emanating from the superior-nasal bulbar quadrant. A high-resolution optical coherence tomography revealed highly cellular infiltrate and hyperreflective mass with significant posterior shadowing. Further exploration of the lesion revealed a white, stringy, cauliflower-like material on the underside of the lesion. Surgical excision and pathology subsequently confirmed a diagnosis of pyogenic granuloma with remnants of silk suture.

CONCLUSIONS

A diagnosis of pyogenic granuloma secondary to retained silk sutures should be considered in patients with a history of intraocular surgery irrespective of other risk factors and length of time since procedure.

[Silk suture granuloma after high orchiectomy]

Suture granuloma is very rare complication of surgical procedures developing from the non-absorbable sutures. The development of suture granuloma is a chronic process and includes multinucleated giant cell formation. It has two step process including the initial reaction of tissue inflicted the passage of the needle and specific inflammatory reaction of the suture material. There is no pathognomonic imaging modality fort he diagnosis of suture granuloma. Surgery is used to for the diagnosis and eradication of the inflammation. A 59 year old man presented with 3*2 cm sized palpable, firm painless nodular mass in the right scrotum. The patient was treated with high orchiectomy before 3 weeks. The mass was excised and reported as silk suture granuloma.

Knot integrity as a function of suture expiration

OBJECTIVE

To test the integrity of knots tied with expired suture and non-expired suture, using 5 different suture materials.

STUDY DESIGN

Knots were tied using expired and non-expired chromic catgut, polyglactin 910, polydioxanone, silk, or coated polyester. Expired sutures were a mean of 10.5 years past the date of expiration stamped on the packaging. Suture packaging was inspected for any flaws or humidity. There were 116 knots with expired suture and 109 non-expired knots. All knots were tied by hand. Suture was soaked in 0.9% sodium chloride for 60 seconds and subsequently transferred to a tensiometer where the tails of the knots were cut to 3 mm length. We compared the tensile strength of knots using a tensiometer to pull the knots until the suture broke or untied. A minimum of 30 knots were needed in order to detect a statistically significant main effect for expired and non-expired sutures with 80% power and a 5% chance of type I error.

RESULTS

A total of 225 knots were tied. Overall, we found no difference in mean tension between expired suture (77.5 ± 31.7 N) and non-expired suture at failure (81.9 ± 30.2 N). All the sutures broke at the knot and none untied. Expired chromic and polydioxanone were significantly weaker than the non-expired suture of the same material (p = 0.002 and p = 0.001, respectively). There was no statistically significant difference in tensile strength between expired absorbable or permanent suture materials. Based on a univariate analysis of variance ([SCAP]ANOVA)[R] there was no difference in the tension at failure between expired and non-expired sutures with suture packet as a covariate. No suture untied when knotted with expired suture.

CONCLUSIONS

Under laboratory conditions, expired chromic and polydioxanone sutures broke at lower tensile strength than non-expired sutures of the same material.

Late abscess formation following indirect hernia repair utilizing silk suture

Inguinal hernia repair is the most common operation performed by pediatric surgeons. The critical portion of the operation is high ligation of the hernia sac, which is classically performed with silk suture. This foreign body has the potential to serve as a nidus for latent infection/rejection that may result in an abscess long after the operation. This complication has rarely been described in the literature. We have cared for six children who have presented with latent inguinal or pelvic abscesses following high ligation of the inguinal hernia sac with silk suture. The purpose of this report is to examine the varied presentations by which latent complications following herniorraphy may manifest. The pediatric surgeon should recognize that not every inguinal mass following a previous inguinal herniorraphy represents a recurrent hernia! A retrospective review of the charts of six patients with late abscess formation following antecedent inguinal hernia repair was undertaken. The details of the initial and operative endeavors were recorded with specific attention to the details of the initial operative hernia repair as well as the suture material utilized. Inguinal hernia repair continues to be the most common operation performed by pediatric surgeons. Utilization of braided, non-absorbable silk suture may result in latent abscess formation and the need for operative drainage of inguinal or pelvic abscess. Today, as other types of suture material are likely equally efficacious in the ability to effectively close the patent processus vaginalis, pediatric surgeons should consider utilizing non-braided, or absorbable suture material for high ligation of the indirect hernia sac to potentially prevent this complication.

Tissue reactions to sutures in the presence and absence of anti-infective therapy

BACKGROUND

In the oral cavity, sutures are placed within tissues of high vascularity in a moist environment with infectious potential. The objective of this study was to evaluate tissue reactions at silk and expanded polytetrafluoroethylene (ePTFE) sutures in the presence and absence of anti-infective therapy (AT).

METHODS

Thirty-six sutures were placed within the mandibular keratinized gingiva in six Beagle dogs. Each animal received one braided silk (4-0) and one ePTFE (CV-5) suture in contra-lateral jaw quadrants at 14, 7, and 3 days prior to biopsy. Three animals received daily AT including topical 2% chlorhexidine solution and a systemic broad-spectrum antibiotic. Biopsy specimens allowed histometric analysis of tissue reactions along the central part of the suture loop including the area of perisutural epithelium, ratio inflammatory cells (ICs)/epithelial cells and IC/fibroblasts, and presence/absence of bacterial plaque in the suture track.

RESULTS

A perisutural epithelial sheath was forming within 3 days. The cross-sectional area of the epithelium increased with time for both suture materials (p=0.003) but was particularly pronounced for the silk sutures in the absence of AT. Clusters of IC were present in the perisutural connective tissue and epithelium. Over time, a more prominent increase in IC/fibroblasts was evident for the silk sutures in the absence of AT. The pooled material revealed a significantly higher IC/fibroblast ratio for silk compared with ePTFE sutures (p=0.017). Bacterial plaque influx was detected in 6/9 silk and 0/9 ePTFE suture channels in the presence, and 6/6 and 3/6 suture channels, respectively, in the absence of AT.

CONCLUSIONS

AT may reduce biofilm formation and inflammation along the suture track. Braided silk, however, elicits more severe tissue reactions than ePTFE regardless of infection control.

Stability of neuropathic pain symptoms in partial sciatic nerve ligation in rats is affected by suture material

Many factors affect the development of neuropathic pain behavior in animal models. In this letter, we describe the differences in the development of neuropathic pain behavior observed when the partial sciatic nerve ligation (PNL) is performed with either a synthetic silk or chromic catgut ligation. To characterize nociceptive changes over time after surgery, neutral plate, hot plate, Von Frey, pinprick, acetone spray and cold plate testing was performed. The results indicated that a chromic catgut ligature caused cold allodynia, chemical hyperreactivity, mechanical hyperalgesia and hypersensitivity that remained present for the entire 56 days post-surgical observation period. With the synthetic silk ligature, comparable functional deficits were present in the initial phase after surgery, but several of these deficits diminished over time 21-28 days post-surgery. In conclusion, performing the PNL using chromic catgut suture thread gives rise to more robust sensory deficits than when synthetic silk is used. Therefore, the material that is used for the ligature in the partial sciatic ligation model has an effect on the outcome of the observed sensory abnormalities.

The inflammatory responses to silk films in vitro and in vivo

Silks have a long history of biomedical use as sutures. Silk can be purified, chemically modified to attach RGD sequences and processed into highly porous scaffolds for tissue engineering. We report biocompatibility studies of silk films (with or without covalently bound RGD) that were seeded with bone-marrow derived mesenchymal stem cells (MSC) and (a) cultured in vitro with human MSC or (b) seeded with autologous rat MSC and implanted in vivo. Controls for in vitro studies included tissue culture plastic (TCP; negative control), TCP with lipopolysaccharide (LPS) in the cell culture medium (positive control), and collagen films; controls for in vivo studies included collagen, PLA and TCP. After 9 h of culture, the expression of the pro-inflammatory Interleukin 1 beta (IL-1beta) and inflammatory cyclooxygenase 2 (COX-2) in human MSC were comparable for silk, collagen and TCP. After 30 and 96 h, gene expression of IL-1beta and COX-2 in MSC returned to the baseline (pre-seeding) levels. These data were corroborated by measuring IL-1beta and prostaglandin E2 levels in culture medium. The rate of cell proliferation was higher on silk films than either on collagen or TCP. In vivo, films made of silk, collagen or PLA were seeded with rat MSCs, implanted intramuscularly in rats and harvested after 6 weeks. Histological and immunohistochemical evaluation of silk explants revealed the presence of circumferentially oriented fibroblasts, few blood vessels, macrophages at the implant-host interface, and the absence of giant cells. Inflammatory tissue reaction was more conspicuous around collagen films and even more around PLA films when compared to silk. These data suggest that (a) purified degradable silk is biocompatible and (b) the in vitro cell culture model (hMSC seeded and cultured on biomaterial films) gave inflammatory responses that were comparable to those observed in vivo.

Human Gingival Tissue Reactions to Silk and Expanded Polytetrafluoroethylene Sutures

BACKGROUND

Wound closure by suturing is a critical and significant event in general as well as in oral surgery. Information regarding tissue reactions to different suture materials appears incomplete and inconsistent, particularly in humans. Thus, the purpose of the present study was to evaluate clinically and histologically tissue reactions to silk and expanded polytetrafluoroethylene (ePTFE) suture materials placed in human oral tissues.

METHODS

Twelve patients undergoing periodontal treatment, who had bilateral periodontal defects in the maxillary premolar and molar region scheduled for resective surgery, were included. In each patient, one single interrupted ePTFE suture (CV-5) and one single interrupted silk suture (4-0) were inserted in gingival tissues in contralateral jaw quadrants 10 days prior to scheduled surgery and a second set of sutures was inserted at 7 days prior to surgery. After placement, the length of the suture embedded in the tissue as well as the slack of the suture loop were measured and tabulated. The measurements were repeated on the day of surgery. At this time biopsy specimens, including the suture loop and surrounding tissue, were harvested and processed for histologic analysis. The inflammatory response was evaluated by measuring the thickness of the perisutural epithelium and the diameter of the connective tissue infiltrate, by estimating the proportion of inflammatory cells to epithelial cells, and by recording the presence or absence of bacterial plaque along the suture track.

RESULTS

At 7 days, silk sutures showed a significantly higher degree of slack of the suture loop than did ePTFE sutures (P= 0.02), while the difference was not significant at 10 days (P= 0.21). The mean change of "tissue bite" was greater for silk compared to ePTFE at 7 as well as at 10 days. However, none of the differences were statistically significant (P= 0.43). The thickness of the perisutural epithelium increased significantly from 7 to 10 days for both suture materials, while the difference in proportion of inflammatory cells to epithelial cells was not significant (P= 0.43). An overall significantly greater diameter of connective tissue infiltrate was present around the silk sutures. Bacterial plaque was detected in 10 of 11 silk and four of 11 ePTFE suture channels at 7 days, and eight of 10 and four of 11 suture channels at 10 days.

CONCLUSIONS

The results revealed that placement of sutures in gingival tissues elicits an inflammatory reaction and that the magnitude of this reaction may vary with the suture material used. Braided silk sutures apparently cause a more extensive inflammatory tissue reaction in an environment characterized by moisture and infectious potential.