Suture Depth Research Articles

Thickness of the Medial Pretarsal Adipose Tissue in the Upper Eyelid among the Japanese Population.

To investigate the medial pretarsal adipose tissue thickness of the upper eyelid in the Japanese population. Sixty-two whole upper eyelids were harvested from 35 Japanese cadavers and fixed in paraffin. The samples were cut into 5 µm sagittal microsections and stained with hematoxylin and eosin, as well as Masson's trichrome. Data obtained from images and measurements were taken with Aperio ScanScope and ImageScope software and underwent statistical analysis. The samples were divided into 3 shapes sagittal cross-sections of the eyelid (triangular, rectangular, and flat) corresponding to the shape of the medial pretarsal adipose tissue. Type I (triangular shape, 48.4%) had a ratio of fat thickness at 1⁄2 tarsal height to peak fat thickness of <0.9, and type IIa (rectangular shape, 30.6%) and IIb (flat shape, 21.0%) had pretarsal adipose tissue thickness to tarsal height ratio of ≥0.2 and <0.2, respectively. The mean values of tarsal thickness at 1⁄2 tarsal height were 1021 µm for the type I group, 1100 µm for the type IIa group, and 764.4 µm for the type IIb group ( p = 0.01). The mean values of fat thickness at 1⁄2 tarsal height were 410.6 µm for the type I group, 303.3 µm for the type IIa group, and 242.6 µm for the type IIb group ( p = 0.26). The thickness of the medial pretarsal adipose tissue was different according to the shape of the sagittal cross-section of the eyelid. Awareness of the medial pretarsal adipose tissue thickness contributes to effective suture placement and safe suture depth during blepharoptosis surgery.

Benefits of Reducing Incision Tension in Hard-To-Close Keloid Surgery.

Benefits of Reducing Incision Tension in Hard-To-Close Keloid Surgery.

Anterior glottoplasty: the effect of inclusion of the vocal fold lamina propria to frequency elevation

Background Anterior glottoplasty is a commonly used treatment for voice feminization. But it remains in dispute over whether to suture of the ligament as part of the procedure. Objectives This study aimed to explore the effect of inclusion of the vocal lamina propia. Material and methods Anterior webs were created in 8 excised canine larynges by sutures placed at 10%, 20%, and 30% of the vocal fold length, respectively. The suture depth was divided into two groups: epithelium layer (Shallow Suture, SS group) and deep layers of vocal fold lamina propia (Deep Suture, DS group). Results For anterior webs between 0% and 30%, the frequency elevation ranged from 3% to 151% of the pre-web fundamental frequency (fo) in SS group and from 13% to 222% in DS group. No significance was found between two groups at three different sutures (p = .486 for suture at 10% of vocal fold length, 0.686 for 20%, 0.886 for 30%, respectively). Conclusions and significance The frequency in excised canine larynx increased continuously as the anterior glottic webs ranged from 0% to 30%. The inclusion of the vocal fold lamina propia does not affect the frequency elevation.

Sensor-Embedded Automatic Grasping Forceps for Precise Corneal Suture in Penetrating Keratoplasty.

In penetrating keratoplasty (PKP), the proper corneal suture placement is very important for successful transplantation and restoring functional vision. Generating sutures with accurate depth is difficult for the surgeon because of the tissue’s softness, lack of depth information, and hand tremors. In this paper, an automatic cornea grasping device is proposed, which detects when the device reaches the target suture depth. When the device reaches the target depth, the device rapidly grasps the cornea to prevent error induced by human hand tremors. In the paper, the performance of the proposed sensor, the actuator, and the device are experimentally verified with ex vivo experiment. The result showed that the proposed device could enhance the accuracy and precision of the corneal suture depth.

Comparison of Simulation-Based versus Cadaveric-Tissue-Based Ocular Trauma Training on Novice Ophthalmologists: Repair of Corneal Laceration Model.

Purpose The aim of this study was to evaluate whether the simulated tissue models may be used in place of animal-based model for corneal laceration repair for surgical skills acquisition. Design Prospective randomized controlled trial. Participants Seventy-nine military and civilian 2nd- and 3rd-year ophthalmology residents and 16 staff ophthalmologists participating in the Tri-Service Ocular Trauma Skills Laboratory at the Uniformed Services University (Bethesda, MD). Methods Resident ophthalmologists underwent preliminary evaluation of their ability to close a 5-mm linear, full-thickness corneal laceration involving the visual axis. They then were randomized to undergo 90 to 120 minutes of either simulator-based (SIM) or swine cadaveric-tissue-based (CADAVER) corneal laceration repair. The same evaluation was performed post training. On a more limited basis, the study was repeated for attending ophthalmologists to act as a pilot for future analysis and test efficacy for "refresher" training. Main Outcome Measures Successful wound closure with secondary outcomes of suture length, tension, depth, and orientation, as graded by attending ophthalmologists. Results No significant difference in CADAVER versus SIM groups in the primary outcome of watertight wound closure of the corneal laceration. CADAVER group performed better than SIM group for certain metrics (suture depth, p = 0.009; length, p = 0.003; and tension, p = 0.043) that are associated with poor wound closure and increased amount of induced corneal astigmatism. For attending ophthalmologists, six of the eight in each group (SIM and CADAVER) retained or improved their skills. Conclusions For resident ophthalmologists, SIM training is sufficient for achieving the primary outcome of watertight wound closure. However, CADAVER training is superior for wound metrics for the ideal closure. For attending ophthalmologists, SIM training may be useful for retention of skills.

Depth and Location of Sacral Suture Placement During Cadaveric Simulation of Open Sacrocolpopexy

OBJECTIVESTo evaluate the location and depth of placement of sacral sutures in a cadaveric sacrocolpopexy model. MATERIALS AND METHODSFollowing a 1-hour instructional session, trainees performed an open sacrocolpopexy on unembalmed cadavers under guidance by a Female Pelvic Medicine & Reconstructive Surgery board-certified surgeon. At completion of the session, the presacral tissues were dissected and the location and depth of each sacral suture was identified. RESULTSA total of 19 sutures were placed by 9 trainees into 8 cadavers. The majority of sutures (14/19, 74%) were placed between L5 and S1. Three sutures (16%) were placed at L5 and 2 (11%) were placed at the S1 vertebral body. The mean depth of the anterior longitudinal ligament (ALL) was 1.4 mm. When assessing depth of suture placement, 13 of 19 (68%) were placed into the ALL without penetrating the disc space. Two sutures (11%) were placed in the tissues superficial to the ALL and 4 (22%) were placed deep to the ALL into the periosteum or disc. CONCLUSIONThis study of cadaveric simulation of open sacrocolpopexy finds that location of sacral suture placement is most commonly at the level of the L5-S1 disc space and that placement of sutures into the underlying disc occurs about 1 in 5 times.

Development of a high-fidelity minimally invasive mitral valve surgery simulator

ObjectivesThe aim of this study was to develop a high-fidelity minimally invasive mitral valve surgery (MIMVS) simulator. MethodsThe process of industrial serial design was applied based on pre-set requirements, acquired by interviewing experienced mitral surgeons. A thoracic torso with endoscopic and robotic access and disposable silicone mitral valve apparatus with a feedback system was developed. The feedback system was based on 4 cameras around the silicone valve and an edge detection algorithm to calculate suture depth and width. Validity of simulator measurements was assessed by comparing simulator-generated values with measurements done manually on 3-dimensional reconstructed micro-computed tomography scan of the same sutures. Independent surgeons tested the simulator between 2014 and 2018, whereupon an evaluation was done through a questionnaire. ResultsThe feedback system was able to provide width and depth measurements, which were subsequently scored by comparison to pre-set target values. Depth did not significantly differ between simulator and micro-computed tomography scan measurements (P = .139). Width differed significantly (P = .001), whereupon a significant regression equation was found (P < .0001) to calibrate the simulator. After calibration, no significant difference was found (P = .865). In total, 99 surgeons tested the simulator and more than agreed with the statements that the simulator is a good method for training MIMVS, and that the mitral valve and suture placement looked and felt realistic. ConclusionsWe successfully developed a high-fidelity MIMVS simulator for endoscopic and robotic approaches. The simulator provides a platform to train skills in an objective and reproducible manner. Future studies are needed to provide evidence for its application in training surgeons.

Observation on the effect of corneal suture depth for wound healing of corneal perforating injury

Objective To observe the effect of corneal suture depth on wound healing after corneal perforating suture surgery. Methods The data of 55 eyes of 55 consecutive cases with corneal perforating injury from Jan.2015 to Jan.2016 were collected. All cases received corneal perforating suture surgery. They were examined with anterior segment panoramic optical coherence tomography (AS-OCT) under panoramic mode. The corneal suture depth, structural changes of cornea and anterior chamber angle were observed and analyzed after surgery. Results All cases were divided into 5 groups according to depths of corneal suture. The depths compared with cornea thickness (CT) were 3/4 CT in 22 cases; 2/3 CT in 25 cases; 1/2 CT in 5 cases; 1/3 CT in 2 cases and 1/4 CT in 1 case. No wound healed or iris prolapse happened in patients with depth≥2/3CT. Corneal wound dislocation, dehiscence and iris attachment occurred in cases with depth ≤1/2CT. Conclusion The corneal suture depth ≥2/3CT for wound healing of patients with corneal perforating injury is effective.Anterior segment panoramic OCT is of value for evaluating outcomes after corneal penetrating suture, determining prognosis, guiding management decisions and surgical planning. Key words: Wound healing; Suture, corneal; Injury, penetrating, corneal

Four-dimensional Microscope-Integrated Optical Coherence Tomography to Visualize Suture Depth in Strabismus Surgery.

The authors report the use of swept-source microscope-integrated optical coherence tomography (SS-MIOCT), capable of live four-dimensional (three-dimensional across time) intraoperative imaging, to directly visualize suture depth during lateral rectus resection. Key surgical steps visualized in this report included needle depth during partial and full-thickness muscle passes along with scleral passes. [J Pediatr Ophthalmol Strabismus. 2017;54:e1-e5.].

The suture pullout characteristics of human and porcine linea alba

There is a substantial prevalence of post-operative incisional hernia for both laparoscopic and laparotomy procedures, but there have been few attempts at quantifying abdominal wound closure methodology in the literature. One method to ascertain a more robust method of wound closure is the identification of the influence of suture placement parameters on suture pullout force. Current surgical practice involves a recommended bite depth and bite separation of 10mm, but the evidence base for this is not clear. In this paper, the suture pullout characteristics of both porcine and human linea alba were investigated to ascertain a suture placement protocol for surgical wound closure. Uniaxial suture pullout force testing on fresh frozen porcine and human linea alba samples was performed using standard materials testing machines. The influence of the number of suture loops, the bite depth and the bite separation of the sutures and the orientation of the sutures with respect to the principal fibre direction in the linea alba were assessed.Results showed a clearly identifiable relationship between pullout force of the suture, bite separation and bite depth, with low suture separation and high suture depth as optimal parameters for increasing pullout force. Resistance to pullout could be improved by as much as 290% when optimizing test conditions. Both human and porcine tissue were observed to exhibit very similar pullout force characteristics, corroborating the use of a porcine model for investigations into wound closure methodology. Orientation of suture application was also found to significantly affect the magnitude of suture pullout, with suturing applied longitudinally across a transverse defect resulting in higher pullout forces for small suture bite separations. Although further assessment in an environment more representative of in vivo conditions is required, these findings indicate that increasing the bite depth and reducing the bite separation with respect to the current surgical recommendations may reduce the risk of post-operative incisional hernia.

Proximity of uterosacral ligament suspension sutures and S3 sacral nerve to pelvic landmarks.

To describe the relationships between pelvic bony landmarks to points along the third sacral nerve and to uterosacral ligament suspension sutures. Three transvaginal uterosacral ligament suspension sutures were placed bilaterally in unembalmed female human cadavers. The third sacral nerve was marked at the foramen (S3a) and at two additional points at 1-cm intervals along its course caudally (S3b, S3c). Three bony pelvic landmarks were identified and marked, including the ischial spine, pubic symphysis, and coccyx. Distances from each landmark to each suture and nerve point were measured. The distance from each landmark to each S3 nerve point was extended radially, encompassing an arbitrary zone in which sutures may be placed and thus where nerve injury may occur. Zones of potential nerve injury included: zone A (closest to the sacral nerve root), zone B, and zone C (closest to the landmark). Descriptive statistics were used and comparisons were made using Student's t test and ANOVA. Ten cadaver specimens were dissected. For the ischial spine, the distances to points S3a, S3b, and S3c were 6.3, 5.4, and 4.6cm respectively. Approximately two thirds of the sutures were noted beyond zone C, indicating a potentially increased risk of nerve injury with suture placement in zones farthest from the ischial spine given their proximity to the sacral nerve. Using the ischial spine as a landmark, increased sacral nerve injury could result from suture placement beyond the mean distance of 4.6cm from the ischial spine. The use of bony landmarks in avoiding sacral nerve injury may be as important as suture depth and angle of suture placement.

Disc at Risk: Sacral Suture Depth in Minimally Invasive Sacrocolpopexy

Disc at Risk: Sacral Suture Depth in Minimally Invasive Sacrocolpopexy

Assessment of suturing in the vertical plane shows the efficacy of the multi-degree-of-freedom needle driver for neonatal laparoscopy

We have developed a thin needle driver with multiple degrees-of-freedom (DOFs) for neonatal laparoscopic surgery. The tip of this needle driver has three DOFs for grasp, deflection and rotation. Our aim was to evaluate the performance of the multi-DOF needle driver in vertical plane suturing. Six pediatric surgeons performed four directional suturing tasks in the vertical plane using the multi-DOF needle driver and a conventional one. Assessed parameters were the accuracy of insertion and exit, the depth of suture, the inclination angle of the needle and the force applied on the model. In left and right direction sutures, the inclination angle of the needle with the multi-DOF needle driver was significantly smaller than that with the conventional one (p = 0.014, 0.042, respectively). In left and right direction sutures, the force for pulling the model with the multi-DOF needle driver was smaller than that with the conventional one (p = 0.036, 0.010, respectively). This study showed that multi-directional suturing on a vertical plane using the multi-DOF needle driver had better needle trajectories and was less invasive as compared to a conventional needle driver.

Randomized Testing Optimizing Parameters for Flexible Endoscopic Suturing in the Stomach Using T-Tag Suture Fasteners

Background: Sutured closure of defects, perforations, and NOTES incisions has been accomplished at flexible endoscopy using T-tagged sutures. Influence of suture depth, angle of tissue approach, method of needle puncture, pre-injection with saline cushion need further study to reduce risk of inadvertent adjacent organ puncture and increase efficacy of this type of suturing. Aim: To study parameters influencing placement of T-tag sutures through stomach: Methods: 4 pigs: 30-34 kg, intralumenal insufflation pressure 12 mm, double channel scope, open abdomen, TAS (Ethicon Endosurgery): 20G needle, 8 mm tag central thread 3.0 Pronova. Parameters randomized in groups of 10: length, 0.5, 1.0, 1.5 mm, angles 90, 45, 15, saline cushion, incision in stomach, overlying adjacent tissue, jabbing, controlled needle advancement. Pull-out and push through forces on bench, stomach thickness. Results: Stomach wall-thickness was 3-4.5 mm. 120 needle punctures were evaluated. At 90 degree angle, exposed needle length of 1.5 cm penetrated gastric serosa (10/10). 1 cm also penetrated through serosal surface in 10/10 and 0.5 cm length in 6/10 (but always reached deep muscle). 1.5 cm exited further than needed to deploy transmural tag in all cases vs 1.0 and 0.5 cm lengths (p = 0.002). Comparing 45 with 90 degree exit angles, serosal penetration was reduced to 2/10 at 0.5, 6/10 at 1.0, and 10/10 but still too long at 1.5 mm. With small intestine (SI) laid over stomach, and angle of 90 degrees, 0.5 cm (7/10 cleanly through the serosa, 6/10 touched SI serosa) vs 1 cm penetrated stomach serosa (10/10) but did not penetrate the small intestine but 7/10 touched serosa of SI. Comparing two methods of needle advancement, with needle length set at 1.5 cm, the jabbing method had needle exit stomach cleanly 9/10 times, with one thrust not exiting. One t-tag penetrated small SI and was delivered into the lumen. An alternative method pushed needle gently while the catheter sheath was held against tissue showed 9/10 exiting the stomach well, without penetrating adjacent tissue. Submucosal injection prevented tags placed with 1.0 mm needle length reaching past serosa in 8/10 vs 0/10 without mucosal cushion. Serosally placed tags with submucosal showed reduction in pull-out force by a third. Needle puncture force was low. Needles were reliable, showing no tendency to blunt with 10 uses. Conclusions: Optimal needle length was slightly longer than tissue thickness (0.5-1 cm). Needle penetration of adjacent tissue was eliminated by limiting needle length and using gentle puncture. Preinjection with saline prevented serosal or adjacent organ penetration. T-tag suturing can be performed safely.

Use of trypan blue for penetrating keratoplasty

Use of trypan blue for penetrating keratoplasty was developed to facilitate the procedure. Trypan blue is injected before and after the addition of 0.25 mL of an ophthalmic viscosurgical device (OVD), sodium hyaluronate, to stain the internal and external cut edge of the cornea as well as the OVD, enabling the surgeon to improve visualization of the incision and suture depth, improve alignment of host and donor tissues, and ensure that all OVD is removed.

Understanding endoluminal gastroplications: A histopathologic analysis of intraluminal suture plications

Background: Endoluminal gastroplication is used to treat GERD, with modest results. Little is known of the histologic reaction to endosutures. Thus, the histologic response to intraluminal plications at different penetration depths within the gastric wall was studied in an animal model. Methods: Intraluminal gastroplications were performed through a laparotomy in 18 New Zealand rabbits. Three sets of everted plications were placed at different penetration depths in each stomach: submucosa (SMpl), muscularis propria (Mpl), and serosa (Spl). Animals were randomized to survival times of 3, 10, or 60 days (respectively, Groups I, II, and III). Plications were compared with a grade scale for each histologic healing phase and gross inspection. Results: Fusion between folds was absent in all groups. Serosa differed from muscularis propria with respect to the proportion of samples with microscopic ischemia (67% vs. 8%; p = 0.015), remaining sutures in Group III (33% vs. 3%; p < 0.05 in a single test of significance, but correction for multiple testing removes this significance), and remaining plications in Group II (96% vs. 54%; p < 0.05 in a single test of significance, but correction for multiple testing removes this significance). All of the total and partial histologic scores for the corresponding healing phase in each group escalated with penetration depth. Overall comparison of the histologic scores showed a significant difference among the plications in the proliferation (Group II, p = 0.004) and maturation (Group II, p = 0.009) phases. Total scores also differed among the plications in Groups II ( p < 0.001) and III ( p < 0.001). Plications were absent in all of Group III, with Spl resulting only in a flat scar. Conclusion: Everted intraluminal gastroplications do not result in fusion between folds irrespective of suture-penetration depth. A flat scar is the final outcome and appears proportional to the amount of ischemia, foreign body reaction, and suture depth. (Gastrointest Endosc 2003;57:868-76.)

3473 Depth of endoscopically placed sutures.

Background: Transoral endoscopic suturing is now being evaluated in the treatment of gastroesophageal reflux disease. This novel procedure involves the placement of sutures into the proximal cardia, with extra-corporeal knot tying and creation of a gastric plication using a knot pusher and cutter. This endoscopic valvuloplasty has been shown to be safe and efficacious in early human clinical trials. A study of the depth of suture placement would further contribute to the understanding of this new technique. Methods: An investigation into the placement and depth of endoscopically placed gastric sutures was conducted in the stomachs of 4 farm pigs. Two of these studies were conducted in live anesthetized farm pigs (50-60lbs) and two in stomachs obtained at slaughter from farm pigs (about 200 lbs). The tissue into which the suture is placed is suctioned into the sewing capsule mounted at the distal end of a standard upper endoscope. After creating endoscopic knots, tissue samples containing a suture were frozen till firm, then trimmed to allow visualization of the deepest part of the suture. Measurements were obtained using a dissecting microscope. Photos were obtained of each suture in place within the tissue. Results: In the first stomach on a live animal, suture depth was compared using 10 seconds (2.5 mm +/-0.72, 8 sutures ) and 30 seconds (3.0 mm +/- 0.93, 8 sutures) of vaccum time. This minor difference was not significant (p=0.44). Stomach thickness associated with these sutures averaged 8.62+/- 2.8 mm). In the second live animal suture depth averaged 3.3 +/- 1.1 mm (6 sutures) with a tissue depth of 6.8+/-3.76 mm. Ten sutures were then placed in each of the two ex vivo stomachs. Suture depth averaged 3.31+/- 1.24 mm and 2.81+/- 0.43 mm respectively. Corresponding tissue thickness was 10.25 +/- 3.81 mm and 7.03+/- 1.19 mm. Overall, endoscopically placed sutures averaged a depth of 2.86+/- 0.91mm with a tissue depth of 8.11+/- 3.07mm. Most of the sutures were placed in the submucosal layer of the stomach. Some sutures entered the muscular wall. On three occasions, all of which were associated with gastric tissue thickness of < 5 mm, the suture penetrated the stomach wall. Conclusions: Increasing vacuum suction time beyond 10 seconds does not significantly affect depth of stitch. Knots created endoscopically have a suture depth mainly into the submucosal layer of the stomach. Stomach wall thickness may determine the depth of endoscopically placed sutures. Background: Transoral endoscopic suturing is now being evaluated in the treatment of gastroesophageal reflux disease. This novel procedure involves the placement of sutures into the proximal cardia, with extra-corporeal knot tying and creation of a gastric plication using a knot pusher and cutter. This endoscopic valvuloplasty has been shown to be safe and efficacious in early human clinical trials. A study of the depth of suture placement would further contribute to the understanding of this new technique. Methods: An investigation into the placement and depth of endoscopically placed gastric sutures was conducted in the stomachs of 4 farm pigs. Two of these studies were conducted in live anesthetized farm pigs (50-60lbs) and two in stomachs obtained at slaughter from farm pigs (about 200 lbs). The tissue into which the suture is placed is suctioned into the sewing capsule mounted at the distal end of a standard upper endoscope. After creating endoscopic knots, tissue samples containing a suture were frozen till firm, then trimmed to allow visualization of the deepest part of the suture. Measurements were obtained using a dissecting microscope. Photos were obtained of each suture in place within the tissue. Results: In the first stomach on a live animal, suture depth was compared using 10 seconds (2.5 mm +/-0.72, 8 sutures ) and 30 seconds (3.0 mm +/- 0.93, 8 sutures) of vaccum time. This minor difference was not significant (p=0.44). Stomach thickness associated with these sutures averaged 8.62+/- 2.8 mm). In the second live animal suture depth averaged 3.3 +/- 1.1 mm (6 sutures) with a tissue depth of 6.8+/-3.76 mm. Ten sutures were then placed in each of the two ex vivo stomachs. Suture depth averaged 3.31+/- 1.24 mm and 2.81+/- 0.43 mm respectively. Corresponding tissue thickness was 10.25 +/- 3.81 mm and 7.03+/- 1.19 mm. Overall, endoscopically placed sutures averaged a depth of 2.86+/- 0.91mm with a tissue depth of 8.11+/- 3.07mm. Most of the sutures were placed in the submucosal layer of the stomach. Some sutures entered the muscular wall. On three occasions, all of which were associated with gastric tissue thickness of < 5 mm, the suture penetrated the stomach wall. Conclusions: Increasing vacuum suction time beyond 10 seconds does not significantly affect depth of stitch. Knots created endoscopically have a suture depth mainly into the submucosal layer of the stomach. Stomach wall thickness may determine the depth of endoscopically placed sutures.

Effect of peripheral suture depth on strength of tendon repairs

The peripheral suture in flexor tendon repairs was originally introduced to "tidy up" the repair site and to improve gliding after core suture placement. More recently, it has been proposed that the peripheral suture can be an important structural component of tendon repair; yet, the effect of peripheral suture technique as an independent factor on the strength of the tendon repair has had little attention. We proceeded to determine whether differing levels of penetration of the tendon by the peripheral suture significantly affect the strength of the repair. We performed tensile tests on two groups of fresh frozen cadaver flexor digitorum superficialis tendons that had lacerations repaired by modified Kessler core sutures: one group had supplemental superficial peripheral sutures while the other group had supplemental deep (half the depth to the center of the tendon) peripheral sutures. The mean failure load of the deep peripheral suture group (38.96 N) was almost 80% greater than that of the superficial suture group (21.68 N). This increased strength may be due to an improved tendon-suture interface, with the deep peripheral suture acting as an auxiliary core suture. Our results with deep peripheral sutures, a simple technique based on a modification of commonly employed suture patterns, demonstrate substantially improved repair strength. This suture has the potential to be used in conjunction with early active finger motion rehabilitation program after flexor tendon repair.

Correction of esophageal atresia with distal tracheoesophageal fistula

Correction of the full spectrum of esophageal atresia with tracheoesophageal fistula (TEF) remains controversial. Circular myotomy and other lengthening procedures have shown promise to reduce tension when a relatively wide gap exists between esophageal segments; nevertheless a relatively high complication rate persists. We believe anastomotic tension is commonly found with repair of this anomaly. Therefore, the construction of the anastomosis will be a primary determinant of success. Twenty-four infants with TEF were admitted, 12 (50%) weighing 2.5 kg, nine (37%) 1.8 to 2.5 kg, and three (13%) 1.8 kg. All underwent gastrostomy and end-to-end single-layer anastomosis. Gaps of up to 4.5 cm were encountered, and in one case a cervical incision was necessary for mobilization of the upper pouch. For eight patients (33%) the gap was at least 2.5 cm and significant anastomotic tension was generated. For the series, there were no anastomotic leaks (all confirmed by barium swallow), reoperations, or surgical complications (there were two late, unrelated deaths). Prophylactic dilation was routinely performed 6 weeks and 3 months postoperatively. Subsequently, seven of the 24 (29%) required additional (one to five) dilatations but are now asymptomatic at least 2 years later. Follow-up for the entire series is 5 months to 5 years. Three infants (13%) required fundoplication for reflux without stricture and two infants (8%) an aortopexy. For successful esophageal anastomosis we consider the following technical points important: (1) no-touch technique to minimize tissue damage, (2) generous (5 to 7 mm) full-thickness suture depth, (3) fine (6/0) monofilament suture to reduce tissue reactivity, and (4) in cases of significant tension, the sutures are preplaced and used to provide traction to eliminate tension during tying. Tension is often unavoidable in TEF, yet a carefully constructed anastomosis will withstand this stress. This approach provides results at least as satisfactory as the reported experience with a variety of techniques.

The Gastropod Thais haemastoma in Georgia: T. h. floridana or T. h. canaliculata?

In the southeastern United States, the snail Thais haemastoma has traditionally been subdivided into two subspecies according to the snail‘s locale, size of shell, number and size of spines, and depth of suture. Only Thais haemastoma floridana is supposed to occur in Georgia; since Thais haemastoma canalicukta is supposedly restricted to the Gulf of Mexico region. In Georgia, specimens fitting the description of both subspecies are common. The author concurs with the conclusions of Butler (1953) and Cunter (1979) in that the subspecies nomenclature is invalid and that they are merely ecological variants. In the southeastern United States, the genus Thais (Family Muricidae) is comprised of two subspecies: Thais haemastoma floridana (Conrad, 1837) and Thais haemastoma canaliculata (Gray, 1839) which are differentiated by locale, shell length, number and size of spines, and depth of the suture (Abbott 1974). Previous studies indicate that the Florida Rock-shell Thais haemastoma jloridana ranges from North Carolina to the West Indies and along the Central American coast to Trinidad; Hay’s Rock-shell Thais haemastoma canaliculata ranges from the west coast of Florida to possibly the northern coast of Mexico (Clench 1947). The drills differ in shell length, with T. h. floridana reaching 75 mm and T. h. canaliculata reaching 105 mm. T. h. jloridana has two or more rows of weak shoulder nodules, w’hile T. h. canaliculata has two rows of strong shoulder nodules. T. h. canaliculata has a more deeply channeled suture (Clench 1947). In Georgia, Thais haemastoma is uncommon (Walker 1981, Walker et al. 1980, Hoese 1969), although it may be common in specific areas (Hoese 1969). In a recent drill survey of Wassaw Sound, Georgia (Walker 1981), Thais haemastoma was found inhabiting oyster bars in two areas: approximately 500 meters north of the mouth of Cabbage Creek, Cabbage Island, and at the Deadman Hammock area, Wassaw Island. The snails were found preying on oysters at or near the mean low water mark in the more saline areas (S x > 18) of Wassaw Sound. Due to the rarity of the snail in Georgia, it does not represent any serious threat to the oyster fishery as it does in more southern waters (Butler 1953). According to locale, the Georgia population should be T. h. floridana because T. h. canaliculata is restricted to the Gulf of Mexico. However, many of the specimens found during the drill survey of Wassaw Sound best fit the description of T. h. canaliculata. For example, 11 out of 23 shells were greater than 75 mm in length, the maximum length Manuscript received April 9,1982; accepted April 27,1982. cited for T. h. floridana. Of these, five were over 80 mm, one was over 90 mm and one was 105 mm in length. The shoulder nodule(s) varied in size and number: 22% with two strong shoulder nodules, 26% with one strong and one weak nodule, 22% with two weak nodules, and 26% with only one weak nodule. The remaining shells were heavily infested with Cliona and not enough of the shell remained for adequate analysis. Furthermore, Hoese (1969) found in Georgia (N=62) 43 mais shells over 79 mm, nine over 89 mm and two over 99 mm. The largest reached 101 mm. Chesnut (1955) found Thais reaching 83 mm in North Carolina. Unfortunately, no descriptive characteristics of the shells were given by either Chesnut (1955) or Hoese (1 969). Specimens collected by the author from Shell Island, Florida, south of Mexico Beach, Florida, were also examined. Of these (N=7), 29% had two strong shoulder nodules, 14% had two weak shoulder nodules, 29% had one weak shoulder nodule and 29% had no shoulder nodules. According to locale, they should all be classified as T. h. canaliculata; however, most, due to the absence of two strong shoulder nodules on the majority of the shells collected, fit the description of T. h. floridana. Mayr (1963) defines a subspecies as “an aggregate of local populations of a species inhabiting a geographic subdivision of the range of the species and differing taxonomically from other populations of the species” (p. 672). The occurrence of shells resembling T. h. canaliculata in Georgia and shells resembling T. h. floridana in the Gulf of Mexico region show that the populations (Gulf vs. Atlantic) are not taxonomically different. Furthermore, Butler (1953) reports finding specimens of both subspecies in Pensacola, Florida, as well as in Barataria Bay, Louisiana. Gunter (1979) reports specimens of both subspecies in Apalachicola Bay, Florida. One can explain the presence of shells resembling T. h. canaliculata in Georgia in three ways: (1) that T. h. cana2iculata was introduced into Georgia waters from the Gulf region; (2) that the Georgia population being taxonomically distinct from T. h. floridana should be given another sub183