Eligibility for giving the treatment or for performing the surgery acc. to Sushruta.

शरीरे चैव शास्त्रे च दृष्टार्थः स्याद्विशारदः |

दृष्टश्रुताभ्यां सन्देहमवापोह्याचरेत् क्रियाः ||५१|| सु.शा.

शरीरे = in body

चैव = च+एव​= वृद्धि संधि, च= and / or +एव= only, specifically

शास्त्रे = in scientific treatise, scriptures

च= and 

दृष्टार्थः= दृष्ट+अर्थ= दृष्ट=see/ direct vision/ practical/obvious + अर्थ= meaning = obvious/ clear/complete knowledge

स्याद्विशारदः= स्यात्=mostly/perhaps+ विशारदः=wise; = Mostly wise

दृष्टश्रुताभ्यां=  तृतीया/ चतुर्थी / पंचमी विभक्ति द्विवचन​ of दृष्ट=seen/sight & श्रुत=heard/listened = by vision/ heard

सन्देहमवापोह्याचरेत् = सन्देह=doubt+ अवापोह्य=remove+ आचरते=perform/practice

क्रियाः=act/process, here its चिकित्सा​=treatment/ surgery

Translated meaning: One should be expert in the complete knowledge of body and scriptures. One should dispel the doubts by his practical and theoretical knowledge and should perform the actions.

Understanding of the Shloka: The person can perform the surgery or can treat if he is wise, can resolve the doubt by his complete knowledge of practical & theoretical aspects.