MINISTRY OF EDUCATION AND TRAINING MINISTRY OF DEFENCE 108 INSTITUTE OF CLINICAL MEDICAL AND PHARMACEUTICAL SCIENCES VIET TAN NGUYEN ANATOMICAL RESEARCH OF ARTERIAL SUPPLY TO THE GREAT AND SECOND TOES[.]
MINISTRY OF EDUCATION AND TRAINING MINISTRY OF DEFENCE 108 INSTITUTE OF CLINICAL MEDICAL AND PHARMACEUTICAL SCIENCES -VIET TAN NGUYEN ANATOMICAL RESEARCH OF ARTERIAL SUPPLY TO THE GREAT AND SECOND TOES BY COMPUTED TOMOGRAPHY ANGIOGRAPHY AND EVALUATING THE RESULTS OF THE TOE-TO-THUMB TRANSFER SURGERY Speciality: Surgery / Orthopaedic trauma and plastic surgery Code: 9720104 ABSTRACT OF MEDICAL PHD THESIS Hanoi – 2023 THE THESIS WAS DONE IN: 108 INSTITUTE OF CLINICAL MEDICAL AND PHARMACEUTICAL SCIENCES Supervisor: Assoc Prof – Ph.D Van Doan Le Prof – Ph.D Khanh Lam Reviewer: This thesis will be presented at Institute Council at: 108 Institute of Clinical Medical and Pharmaceutical Sciences Day Month Year The thesis can be found at: National Library of Vietnam Library of 108 Institute of Clinical Medical and Pharmaceutical Sciences INTRODUCTION The thumb is the most important digit and constitutes approximately 50 % of the hand function Therefore, when the thumb is lost, the indication of thumb reconstruction is always requested In thumb reconstruction, toe-to-thumb transfer is a gold standard procedure compared to other traditional methods like phalangization, thumb metacarpal lengthening, and osteoplastic reconstruction, pollicization The common types of toe-to-thumb transfers are the second toe, great toe, trimmed great toe, and the great toe wrap-around transfers In general, the basic issues related to it have been comprehensively reported, for example: surgical indications, the surgical technique of toe harvesting and toe transplantation to the thumb, and post-operatively monitoring and treatment However, according to a study by Lin P.Y et al (2011) consisting of evidence-based medicine, there were still several different opinions and comments about toe flap selection, donor foot morbidity, and functional, aesthetic outcomes amongst different methods of the toeto-thumb transfers In the toe-to-thumb transfer surgery, the dorsalis pedis artery (DPA) and the first dorsal metatarsal artery (FDMA) are preferred for use as the arterial pedicle of the toe flaps thanks to the following advantages: these two arteries are superficial and easy to dissect, and the vascular pedicles are long with large diameters However, many studies have shown that DPA and especially FDMA have great anatomical variability In Vietnam, although the first free toe-to-thumb transfer surgery was performed in 1988 by Huy Phan Nguyen, until now it has not been widely applied, the number of reports is limited with small sample sizes, and the conclusions related to the results of the transferred toe, the donor foot morbidity have not been described in detail Regarding to the anatomical study of the arteries supplying blood to the great and second toe flaps, there were only two studies of Vietnam Military Medical University in 2017 and 2022 based on traditional dissection on Vietnamese cadavers preserved in formalin As a response to the above, we performed research entitled “Anatomical research of arterial supply to the great and second toes by computed tomography angiography and evaluating the results of the toe-to-thumb transfer surgery” with two following targets: Describing the anatomical characteristics of the arteries supplying blood to the great and second toe flaps in Vietnamese adults using computed tomography angiography Evaluating the results of the toe-to-thumb transfer surgery and the donor foot morbidity ARRANGEMENT OF THE THESIS The thesis consists of 116 pages (excluding references and appendices), with the following main parts: - Introduction: pages - Chapter Literature Overview: 31 pages - Chapter Subjects and methods: 22 pages - Chapter Results: 33 pages - Chapter Discussion: 26 pages Conclusion: pages - The thesis has 35 tables, 45 figures - References: 149 documents (15 Vietnamese, 134 foreign languages) - 06 articles related to the topic have been published Chapter LITERATURE OVERVIEW 1 Thumb amputation and reconstruction methods 1.1.1 Classification of thumb amputation Campbell – Reid D.A (1960) classified thumb defects into four groups: Group I: Amputation distal to the metacarpophalangeal (MCP) joint, leaving an adequate stump of proximal phalanx or of proximal and distal phalanges Group II: Amputation distal to or through the MCP joint leaving a stump of inadequate length Group III: Amputation through the metacarpal leaving some intrinsic musculature Group IV: Amputation at the carpometacarpal (CMC) joint 1.1.2 Thumb reconstruction via non-microsurgical techniques - First web deepening method - Metacarpal lengthening - Osteoplastic reconstruction - Pollicization - The pedicled toe-to-thumb transfer surgery 1.1.3 Thumb reconstruction by free toe-to-thumb transfer surgery - Great toe transfer - Trimmed great toe transfer - Great toe wrap-around transfer - Second toe transfer 1.2 Anatomical study of arteries supplying to the great and second toe flaps 1.2.1 Overview of the arterial anatomy of the foot According to Trinh Van Minh, the foot is supplied blood by three main arterial sources: the dorsalis pedis artery, the lateral plantar artery, and the medial plantar artery 1.2.2 Anatomical study of the arterial supply of the great and second toe flaps in the world 1.2.2.1 Anatomical variations of the dorsalis pedis artery * Frequency of absent DPA This rate is 12% in Huber J.F.’s study (1941); 4/70 (5,7%) in Leung P.C.’s (1983); 6,7% in Yamada T.’s (1993); 20% in Martínez Villén G.’s (2002); 9,5% in Rajeshwari M.S.’s (2013); 2% in George A (2020) * The course of DPA in the ankle According to Huber J.F., most of DPAs travel in the middle third of the ankle in the direction from the mid-point between two malleoli to the proximal end of the first intermetatarsal space * Caliber In the study of Man D (1980), the average external diameter of DPA at the upper limit of the extensor retinaculum is 2,79 mm In the study of Yamada T (1993) with the traditional method of cadaver dissection, the mean diameter of DPA at 3cm distal to the ankle is 2,07 ± 0,77mm 1.2.2.2 First dorsal metatarsal artery and its variations * Variations in the origin of the first dorsal metatarsal artery According to Zhu J., all FDMAs originate from DPAs However, the artery has other origins from the plantar arteries (2%), from the lateral tarsal artery (9,4%) * Variations in the location related to the first dorsal interosseous muscle the rate of absent or slender FDMA is 12% in Gilbert A.’s study (1976), 18,5% in Leung P.C.’s (1983), 5% in Gautam A (2020) In relation to the first dorsal interosseous muscle, FDMA can lie superficially (on the muscle or superficially within it) or deep (beneath the muscle) Most studies have shown that the most common type of FDMA is superficial (the artery course superficially on the muscle) * Caliber The diameter of FDMA ranges from to 1,5mm according to many studies * Classifications of the first dorsal metatarsal artery To simplify, many authors (Greenberg B.M (1988), Earley M.J (1989), ChávezAbraham V (2003), Strauch B (2006), Zhu J (2006), Xu L (2016)) classified FDMA into main types: superficial type, deep type, absent type like type I, II, III of Gilbert A.’s classification 1.2.2.3 First plantar metatarsal artery and its variations FPMA can be a branch of DPA or FDMA 1.2.2.4 The communication between the first dorsal and plantar metatarsal arteries in the first toe web space and the correlation of the blood supply to toes Based on experience in the clinical application of toe transfers, experts from Chang Gung Memorial Hospital, Taiwan classified vascular patterns in the first toe web space into types: FDMA is dominant, accounting for 70% FPMA is dominant, accounting for 20% FDMA and FPMA have similar diameters, accounting for 10% 1.2.2.5 The digital arteries According to May J.W (1977), the average diameter of the lateral plantar digital artery of the great toe and medial plantar digital artery of the second toe are 1,1mm and 0,9mm, respectively 1.2.3 Studying the arterial anatomy of the great and second toe flaps through diagnostic imaging techniques in the world In 2006, Zhu J conducted an anatomical study of FDMA via Doppler sonography on 374 feet The results showed that FDMA of the 374 feet all originated from DPA with an average caliver of ± 0,5mm Angiograhic methods can be catheter angiography (Leung P.C (1983), Greenberg B.M (1988), Yamada T (1993), Upton J (1998), Cheng M.H (2006)) and minimally invasive diagnostic imaging procedure (Hou Z (2013), Xu L (2016)) In 2006, Xu L et al reported the use of CTA to preoperatively investigate the arterial supply of the toe flaps on 158 feet of 79 patients who underwent toe-to-hand transfer surgeries As a result, CTA was able to investigate clearly the types of FDMA according to Gilbert A.’s classification, thus helping the surgical process to be favorable 1.2.4 Anatomical study of the arterial supply of the great and second toe flaps in Vietnam We have just found only two recent studies by Anatomical Department of Vietnam military medical university in 2017 and 2022 In 2022, based on the traditional dissection on 50 cadaveric feet preserved by formaldehyde embalming fluid, the authors showed the results of the origin, location, pathway of DPA, FDMA as follow: - DPA originates mainly from the anterior tibial artery (49/50), accounting for 98%, not in (01/50) accounting for 2%; average diameter is 3.74 ± 0.69 (mm); average length 7.61 ± 1.16 cm - FDMA originates from DPA (48/50), accounting for 96%, from the deep plantar artery (01/50) accounts for 2%, from the plantar artery arch (01/50) accounts for 2%; original diameter and end diameter: 1.84 ± 0.36 mm and 1.54 ± 0.35 mm, respectively 1.3 Applying free toe transfer for thumb reconstruction 1.3.1 In the world In general, the basic issues related to indications of the surgery, selection of toe transfer, outcomes in reconstructed hands, and morbidity in donor foot have been systematically and detailedly mentioned 1.3.2 Results of the toe-to-thumb transfer surgery In the evidence-based research of Lin P.Y et al in 2011, the author collected 633 english articles related to toe-to-thumb transfer surgery In which, 25 studies representing 450 toe-to-thumb transfers met the inclusion criteria They included 101 second toe transfers, 196 great toe transfers, 122 wrap-around transfers, and 31 TGT transfers for thumb reconstruction The results showed that: the average survival rate was 96,4%; no statistically significant differences could be detected between the four transfers with regards to survival, arc of motion, total active motion, grip and pinch strength, and static two-point discrimination 1.3.3 Donor site morbidity In 2016, Sosin M did evidence-based research via 56 articles evaluating the donor foot morbidity after toe transfer The results showed that functional foot impairment could occur after various toe transfer procedures due to altered biomechanics of weight distribution In particular, great toe transfer left more complications and impacts on the donor foot than the second toe transfer 1.3.4 New trends in toe-to-thumb transfer surgery (1) Immediate toe-to-thumb transfer after acute hand injuries (2) Applying diagnostic imaging techniques to preoperatively investigate the vascular pedicle of toe flaps 1.3.5 In Vietnam Nowadays, besides 108 Military Central Hospital, numerous hospitals are performing this surgery such as Le Huu Trac National Burn Hospital, Saint Paul Hospital, Viet Duc Hospital, Ho Chi Minh Trauma and Orthopedic Hospital, 115 Hospital, Hue Central Hospital… However, the sample sizes in the reports related to the surgery were still limited and the analysis of the results was only the initial comments Chapter SUBJECTS AND METHODS 2.1 Anatomical study of the arteries supplying blood to the great and second toe flaps using 320-detector row computed tomography angiography 2.1.1 Subjects Thirty-six Vietnamese adults with 72 intact feet underwent CTA to investigate the arterial anatomy of the toe flaps preoperatively in the Department of Diagnostic Imaging – 108 Military Central Hospital from June 2017 to December 2019 Out of these 36 patients, 22 received toeto-thumb transfer surgeries in 108 military central hospital Inclusion criteria: Adults, age ≥ 18 Both ankles and feet were intact The patient did not have any diseases or injuries affecting the arterial system to both ankles and feet The patient had to agree, understand and accept the risk factors when performing CTA with contrast injection Exclusion criteria: Pregnant and lactating women Patients with a history of chronic cardiology diseases, diabetes, asthma, allergies 2.1.2 Method 2.1.2.1 Design: Prospective, cross-sectional study 2.1.2.2 Materials: 320-detector row CT scanner (Aquilon One, Toshiba Medical System, Tokyo, Japan) Power injector (Medrad Stellant, Bayer, USA) Nonionic contrast agent bolus (Xenetic 350 mg/100 ml vial, Guerbet, France) 2.1.2.3 CT scanning * Preparation * CTA protocol: - CT acquisition was performed with the following parameters: 120 12 foot and compare with normal non-operated foot The change of foot dimension was identified by finding the change in footwear or patient’s feeling when wearing shoes and comparing with a normal non-operated foot New foot callus, pain point, cold intolerance were looked for Complications, deformity of the adjacent toe were looked for through clinical examination and X-ray Foot function was accessed based on the foot and ankle disability index (FADI) questionnaire 2.3 Statistical analysis All data were collected and analyzed by SPSS 22.0 software (IBM, Armonk, NY) Chapter Results 3.1 Results of anatomical study 3.1.1 Patient characteristics - The age average was 32,0 years (19 – 59 years) - The male-to-female ratio was 31/5 (86,2% / 13,8%) 3.1.2 Dorsalis pedis artery - The present rate of DPA was: 67/72 (93,1%) - In almost cases (91,7%), DPA ran in the middle third of the ankle from the mid-point between two malleoli to the posterior end of the first intermetatarsal space In one case (1,4%), the artery deviated to the lateral third of the ankle, from the lateral malleolus to the posterior end of the first intermetatarsal space - In 67 feet where DPAs were present: the diameter at the origin: 3,22 ± 0,59mm (2,0 – 4,5mm); the diameter at the termination: 2,56 ± 0,51mm (1,5 – 3,6mm) 13 - No statistically significant difference could be detected between the diameter of DPA between the right and left side (p > 0,05) - 34/36 patients (94,4%) had the bilateral symmetric of DPA with regards to the pathway, size in both sides 3.1.3 Deep plantar arch - Almost (91,7%) deep plantar arches was a circulatory anastomosis formed from the deep plantar artery and the lateral plantar artery - The diameter of the deep plantar artery was: 2,28 ± 0,48mm (1,5 – 3,5mm) - The diameter of the lateral plantar artery was: 1,98 ± 0,54mm (1,2 – 3,3mm) 3.1.4 First dorsal metatarsal artery - The present rate of FDMA was: 51/72 (70,8%) - Most of FDMAs (66,7%) originated from DPAs - The distance from the origin of FDMA to the first MTP joint cleft plane was: 48,26 ± 4,91mm (40 – 58mm) - The diameter at the origin was: 1,98 ± 0,40mm (1,2 – 2,8mm) - The diameter at the termination was: 1,67 ± 0,28mm (1,0 – 2,2mm) - The rate of Gilbert type I, II, III was 52,8%; 18,1%; and 29,2%, respectively - 16 of 36 patients (44,4%) had an asymmetry of FDMA between the two feet 3.1.5 First plantar metatarsal artery - The present rate of FPMA was: 33/72 (45,8%) - The diameter at the origin was: 1,89 ± 0,28mm (1,3 – 2,4mm) 3.1.6 Arterial anatomy of the first toe web space In the correlation between FDMA and FPMA in the blood supply to the great and second toes, there were main types: - The dominant FDMA: 39/72 (54,2%) - The dominant FPMA: 21/72 (29,2%) - Equal between arteries: 12/72 (16,6%) 14 Table 3.11 Diameter and location of the origin of the digital arteries in the first toe web space Diameter at the ̅± Location of the origin (𝐗 ̅ ± SD) origin (𝐗 SD) Lateral plantar digital artery 1,48 ± 0,23mm 2.89 ± 3.02 mm distal to the of the great toe (n = 72) (0,9 – 2,0mm) first MTP joint cleft plane Medial plantar digital artery 1,21 ± 0,18mm 2,96 ± 3,11mm distal to the of the second toe (n = 72) (0,9 – 1,8mm) first MTP joint cleft plane Latral dorsal digital artery 0,69 ± 0,31mm 5,69 ± 4,64mm proximal to of the great toe (n = 17) (0,3 – 1,3mm) the first MTP joint cleft plane Arteries 3.2 Results of clinical study 3.2.1 Characteristics of the study group - Age, gender: The average age of 55 patients in this study was 29,4 years (7 – 61 years).The male-to-female ratio was: 45/10 = 4,5/1 - Causes of thumb amputations: The main causes of thumb loss in this study were labor accidents and daily-life accidents, accounting for 52/55 cases (94,6%) - Characteristics of injured hands: Thumb amputations occurred in the right hand (usually the dominant hand) more than in the left - The condition of remaining long fingers: Intact long fingers: 36/55 (65,5%); Having 1-2 long fingers amputated or damaged: 19/55 (34,5%) 3.2.2 Characteristics of thumb amputations and toe transfers Table 3.12 Thumb amputations and types of toe transfers (n = 55) Thumb TGT transfer amputation level Second toe Total transfer Group I (0%) (3,6%) (3,6%) Group II 13 (23,6%) 16 (29,1%) 29 (52,7%) 15 Group III (5,5%) (9,1%) (14,5%) Group IV 16 (29,1%) (0%) 16 (29,1%) Total 32 (58,2%) 23 (41,8%) 55 (100%) 3.2.3 Primary results 3.2.3.1 In the hand - Survival rate The complete survival rate was: 54/55 flaps (98,2%) The partial necrosis rate was: 1/55 flap (1,8%) The complete necrosis rate was: 0/55 flap (0%) - Complications: + Vascular occlusion: five cases (one of arterial and venous occlusion, two of arterial occlusion, two of venous occlusion) + Infection: was seen in two elder patients 3.2.3.2 In donor foot There were two cases having complications of infection, necrosis of the epidermis of the surgical wound area of the foot 3.2.4 Primary results and related factors - Relationship between primary results and amputation levels: No statistically significant difference could be detected among amputation levels with regards to primary results (p > 0,05) - Relationship between primary results and types of toe transfers: No statistically significant difference could be detected between TGT transfer and second toe transfer with regards to primary results (p > 0,05) - Relationship between primary results and the number of venous anastomoses: The rate of venous occlusion in the group performed only one venous anastomosis was higher than the group performed from two or more The difference was statistically significant with p < 0,05 16 3.2.5 Application results of CTA-320 films into the surgery - The preoperative CTA images were consistent with the anatomical results obtained in the surgical findings (100%) - Comparing operative time, primary results between group received preoperative CTA and without preoperative CTA showed no statistically significant difference with p > 0,05 3.2.6 Secondary results in the hand (n = 54, Following-up time on each patient ≥ 12 months) 3.2.6.1 Results of motor recovery - Results of motor recovery in amputations without thenar muscles Two out of 16 cases did not achieve opposition, could only grasp large objects (suchs as mugs, cups) but coud not pick due to a mispositioning of the reconstructed thumb 14 out of 16 cases achieved basic opposition (the thumb could touch to the long fingers) Out of these 14 cases, nine had the pinch strength > 30% of uninjured side, 11 had grip strength > 50% uninjured side, opposition score achieved 4-9 - Results of motor recovery in amputations preserving thenar muscles There were 38 thumb amputations preserving thenar muscles Out of these 38 cases, 15 were reconstructed by TGT transfers and 23 by second toe transfers Results of motor recovery in this group were as following Pinch strength (% uninjured side): 59,4 ± 25,4 Grip strength (% uninjured side): 83,8 ± 18,3 Total active motion of MC, IP joints: 45,1 ± 28,7o Kapandji socre: 8,3 ± 1,5 3.2.6.2 Results of sensory recovery S2PD was: 13,9 ± 5,0mm Sensory recovery grade S3+ was obtained in 42/54 cases (77,8%), grade S3 in 12/54 cases (22,2%) 17 3.2.6.3 Complications and management Tendon adhesions: 17/54 (31,4%); First web space contracture: one case that underwent a second operation to release There were one case of malunion, one case of nonunion, and four cases of malalignments of reconstructed thumb 3.2.6.4 Patient-reported outcomes QuickDASH score was: 8,8 ± 13,1 MHQ overall score was: 84,7 ± 13,4 3.2.7 Secondary results and related factors - Relationship between secondary results and thenar muscles status: Comparing results of motor recovery (Pinch, grip, Kapandji opposition scores) and QuickDASH, MHQ scores between amputations group without thenar muscles and group preserving thenar muscles showed a statistically significant difference with p < 0,05 - Relationship between secondary results and the status of long fingers: Grip strength obtained in patients group having intact long fingers was higher than group having injured long fingers These differences were statistically significant with p < 0,05 - Relationship between bony fixation methods and complications: No statistically significant difference could be detected in results among fixation methods with p > 0,05 - Comparing results of motor recovery (Pinch, grip, Kapandji opposition scores), sesory recovery and QuickDASH, MHQ scores between TGT transfer and second toe transfer did not show a statistically significant difference with p > 0,05 3.2.8 Donor foot morbidity - The average FADI score was: 96,5 /100 - The There was a statistically significant difference among the group 18 of great toe transfer and the group of second toe transfer with regard to FADI score (p < 0,05) Chapter DISCUSSION 4.1 Anatomical features of the arterial supply of the great and second toes 4.1.1 Pos and cons of applying CTA in anatomical research Compared with the cadaver dissection, studying the arterial anatomy on CTA images has the following advantages (1) The diameter is recorded under the physiological perfusion pressure of the heart in the living body and is close to the actual values (2) The recorded diameter is the internal diameter and reflects the true consideration of the amount of blood flow to the tissue in the living body (3) The data and results are reproducible 4.1.2 Significance of applying CTA to preoperatively investigate vascular anatomy In our study, the CTA results also coincided with surgical results (100%) Therefore, the use of preoperative CTA to assess the arterial supply for the toe flaps will help the surgeon to predict the difficulties, choose the donor foot, thus making the toe transfer surgery more convenient 4.1.3 Anatomy of the arterial supply of the great and second toes 4.1.3.1 Dorsalis pedis artery DPA has a diameter of about 2,0 – 3,0mm and varies from studies to studies due to the different measurement locations and different races In our study, the diameter of DPA at its origin was 3,22 ± 0,59mm and at its termination was 2,56 ± 0,51mm From these