Pattern variable checking syntax-rules: https://groups.google.com/forum/#!topic/comp.lang.scheme/2DY9nvRGM2s

prefixed-syntax-rules.sls

;; -*- mode: scheme -*-
#!r6rs
(library (prefixed-syntax-rules)
    (export prefixed-syntax-rules)
    (import (rnrs))

(define-syntax prefixed-syntax-rules
  (lambda (x)
    (define (check-pattern p)
      (define (prefiex? id)
        (let ((sym (syntax->datum id)))
          (and (not (pair? sym))
               (or (not (symbol? sym))
                   (eq? sym '_)
                   (eq? sym '...)
                   (char=? (string-ref (symbol->string sym) 0) #\?)))))
      (syntax-case p ()
        ((id rest ...)
         (prefiex? #'id)
         (check-pattern #'(rest ...)))
        (((a . d) rest ...)
         (and (check-pattern #'a) (check-pattern #'d))
         (check-pattern #'(rest ...)))
        ((#(e ...) rest ...)
         (check-pattern #'(e ...))
         (check-pattern #'(rest ...)))
        (() #t)
        (k (prefiex? #'k))))

    (define (check-patterns p*)
      (syntax-case p* ()
        (() #'#t)
        ((p1 p* ...)
         (check-pattern #'p1)
         (check-patterns #'(p* ...)))
        (_ #f)))
    (syntax-case x ()
      ((_ (literals ...) (pat templ) ...)
       (check-patterns #'(pat ...))
       #'(syntax-rules (literals ...) (pat templ) ...))
      (_ (syntax-violation 'prefixed-syntax-rules
                           "pattern doesn't have ?" '#'x)))))
)

test.scm

#!r6rs
(import (except (rnrs) syntax-rules)
        (for (rename (prefixed-syntax-rules)
                     (prefixed-syntax-rules syntax-rules))
             expand))

(define-syntax foo
  (syntax-rules ()
    ((_ (?foo ?bar) "hoge" ?oops)
     (let ((oops (?oops)))
       (+ ?foo oops)))))

(display (foo (1 2) "hoge" (lambda () 1))) (newline)